# Patent

## Title
Field pea cultivar CDC 0007

## Abstract

A field pea cultivar designated CDC 0007 is disclosed. The invention relates to the seeds of field pea cultivar CDC 0007, to the plants of field pea cultivar CDC 0007, to plant parts of field pea cultivar CDC 0007 and to methods for producing a field pea plant produced by crossing field pea cultivar CDC 0007 with itself or with another field pea cultivar. The invention also relates to methods for producing a field pea plant containing in its genetic material one or more transgenes and to the transgenic field pea plants and plant parts produced by those methods. This invention also relates to field pea cultivars or breeding cultivars and plant parts derived from field pea cultivar CDC 0007, to methods for producing other field pea cultivars, lines or plant parts derived from field pea cultivar CDC 0007 and to the field pea plants, varieties, and their parts derived from use of those methods. The invention further relates to hybrid field pea seeds, plants and plant parts produced by crossing field pea cultivar CDC 0007 with another field pea cultivar.

## Background
BACKGROUND OF THE INVENTION
The present invention relates to a new and distinctive field pea, Pisum sativum (L) designated CDC 0007. All publications cited in this application are herein incorporated by reference.
There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possesses the traits to meet the program goals. The goal is to combine in a single cultivar an improved combination of desirable traits from the parental germplasm. These important traits may include higher seed yield, resistance to diseases and insects, better stems and roots, tolerance to drought and heat, and better agronomic quality.
Field pea (Pisum sativum L.), an annual legume, is also commonly referred to as pea and dry pea. Field pea most likely originated in Southwest Asia and is widely grown in Russia, China, Canada, Europe, Australia and the United States. It is primarily used as a grain crop, for livestock feed or as a vegetable. Field pea is a grain legume commonly used throughout the world in human cereal grain diets. Field pea is among the oldest crops in the world as it was cultivated as early as 9000 years ago.
The field pea is one of the world's important legume crops and is grown on over 25 million acres worldwide. Annual worldwide production is estimated at 2.5 million metric tons of dry beans harvested from 9 million hectares. Plant breeders have played an important role in the development of the field pea industry as it exists in the United States and Canada today.
The protein in field pea seed is rich in the amino acids lysine and tryptophan as compared to cereal grains. Peas contain high levels of carbohydrates, are low in fiber and contain a large percentage of total digestable nutrients, which makes them excellent livestock feed. Also, field peas contain 5 to 20% less of the trypsin inhibitors than soybean. This allows it to be directly fed to livestock without having to go through the extrusion heating process.
Field pea is a cool-season annual herbaceous legume. There are two main types of field peas. One type has round seeds and is used primarily for food and feed. The other type has wrinkled seeds and is usually harvested when immature and used for freezing and canning. Pea seeds may have either green or yellow cotyledons under a white or sometimes pale green seed coat. Field pea seed weighs from 100 to 350 g/1000 seeds when dry and mature.
Most pea varieties produce white to reddish-purple flowers, which are self-pollinated. Each flower will produce a pod containing four to nine seeds. Pea varieties have either indeterminate or determinate flowering habit. Determinate flowering varieties will flower for long periods and ripening can be prolonged under cool, wet conditions. Indeterminate varieties are later in maturity ranging from 90 to 100 days. Determinate varieties will flower for a set period and ripen with earlier maturity of 80 to 90 days. Field peas are sensitive to heat stress at flowering, which can reduce pod and seed set.
Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of cultivar used commercially (e.g., F1 hybrid cultivar, pureline cultivar, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection.
The complexity of inheritance influences choice of the breeding method. Backcross breeding is used to transfer one or a few favorable genes for a highly heritable trait into a desirable cultivar. This approach has been used extensively for breeding disease-resistant cultivars. Various recurrent selection techniques are used to improve quantitatively inherited traits controlled by numerous genes. The use of recurrent selection in self-pollinating crops depends on the ease of pollination, the frequency of successful hybrids from each pollination, and the number of hybrid offspring from each successful cross.
Each breeding program should include a periodic, objective evaluation of the efficiency of the breeding procedure. Evaluation criteria vary depending on the goal and objectives, but should include gain from selection per year based on comparisons to an appropriate standard, overall value of the advanced breeding lines, and number of successful cultivars produced per unit of input (e.g., per year, per dollar expended, etc.).
Promising advanced breeding lines are thoroughly tested and compared to appropriate standards in environments representative of the commercial target area(s) for three or more years. The best lines are candidates for new commercial cultivars; those still deficient in a few traits may be used as parents to produce new populations for further selection.
These processes, which lead to the final step of marketing and distribution, usually take from eight to 12 years from the time the first cross is made. Therefore, development of new cultivars is a time-consuming process that requires precise forward planning, efficient use of resources, and a minimum of changes in direction.
A most difficult task is the identification of individuals that are genetically superior, because for most traits the true genotypic value is masked by other confounding plant traits or environmental factors. One method of identifying a superior plant is to observe its performance relative to other experimental plants and to a widely grown standard cultivar. If a single observation is inconclusive, replicated observations provide a better estimate of its genetic worth.
The goal of field pea plant breeding is to develop new, unique and superior field pea cultivars and hybrids. The breeder initially selects and crosses two or more parental lines, followed by repeated selfing and selection, producing many new genetic combinations. The breeder can theoretically generate billions of different genetic combinations via crossing, selfing and mutations. The breeder has no direct control at the cellular level. Therefore, two breeders will never develop the same line, or even very similar lines, having the same field pea traits.
Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic and soil conditions, and further selections are then made, during and at the end of the growing season. The cultivars which are developed are unpredictable. This unpredictability is because the breeder's selection occurs in unique environments, with no control at the DNA level (using conventional breeding procedures), and with millions of different possible genetic combinations being generated. A breeder of ordinary skill in the art cannot predict the final resulting lines he develops, except possibly in a very gross and general fashion. The same breeder cannot produce the same cultivar twice by using the exact same original parents and the same selection techniques. This unpredictability results in the expenditure of large amounts of research monies to develop superior new field pea cultivars.
The development of new field pea cultivars requires the development and selection of field pea varieties, the crossing of these varieties and selection of superior hybrid crosses. The hybrid seed is produced by manual crosses between selected male-fertile parents or by using male sterility systems. These hybrids are selected for certain single gene traits such as pod color, flower color, pubescence color or herbicide resistance which indicate that the seed is truly a hybrid. Additional data on parental lines, as well as the phenotype of the hybrid, influence the breeder's decision whether to continue with the specific hybrid cross.
Pedigree breeding and recurrent selection breeding methods are used to develop cultivars from breeding populations. Breeding programs combine desirable traits from two or more cultivars or various broad-based sources into breeding pools from which cultivars are developed by selfing and selection of desired phenotypes. The new cultivars are evaluated to determine which have commercial potential.
Pedigree breeding is used commonly for the improvement of self-pollinating crops. Two parents which possess favorable, complementary traits are crossed to produce an F1. An F2 population is produced by selfing one or several F1s. Selection of the best individuals may begin in the F2 population; then, beginning in the F3, the best individuals in the best families are selected. Replicated testing of families can begin in the F4 generation to improve the effectiveness of selection for traits with low heritability. At an advanced stage of inbreeding (i.e., F6 and F7), the best lines or mixtures of phenotypically similar lines are tested for potential release as new cultivars.
Mass and recurrent selections can be used to improve populations of either self- or cross-pollinating crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population in which further cycles of selection are continued.
Backcross breeding has been used to transfer genes for a simply inherited, highly heritable trait into a desirable homozygous cultivar or inbred line which is the recurrent parent. The source of the trait to be transferred is called the donor parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. After the initial cross, individuals possessing the phenotype of the donor parent are selected and repeatedly crossed (backcrossed) to the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent.
The single-seed descent procedure in the strict sense refers to planting a segregating population, harvesting a sample of one seed per plant, and using the one-seed sample to plant the next generation. When the population has been advanced from the F2 to the desired level of inbreeding, the plants from which lines are derived will each trace to different F2 individuals. The number of plants in a population declines each generation due to failure of some seeds to germinate or some plants to produce at least one seed. As a result, not all of the F2 plants originally sampled in the population will be represented by a progeny when generation advance is completed.
In a multiple-seed procedure, field pea breeders commonly harvest one or more pods from each plant in a population and thresh them together to form a bulk. Part of the bulk is used to plant the next generation and part is put in reserve. The procedure has been referred to as modified single-seed descent or the pod-bulk technique.
The multiple-seed procedure has been used to save labor at harvest. It is considerably faster to thresh pods with a machine than to remove one seed from each by hand for the single-seed procedure. The multiple-seed procedure also makes it possible to plant the same number of seeds of a population each generation of inbreeding. Enough seeds are harvested to make up for those plants that did not germinate or produce seed.
In addition to phenotypic observations, the genotype of a plant can also be examined. There are many laboratory-based techniques available for the analysis, comparison and characterization of plant genotype; among these are Isozyme Electrophoresis, Restriction Fragment Length Polymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs), Amplified Fragment Length polymorphisms (AFLPs), Simple Sequence Repeats (SSRs—which are also referred to as Microsatellites), and Single Nucleotide Polymorphisms (SNPs).
Isozyme Electrophoresis and RFLPs have been widely used to determine genetic composition. Shoemaker and Olsen, (Molecular Linkage Map of Soybean (Glycine max L. Merr.) p 6.131-6.138 in S. J. O'Brien (ed) Genetic Maps: Locus Maps of Complex Genomes, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., (1993)) developed a molecular genetic linkage map that consisted of 25 linkage groups with about 365 RFLP, 11 RAPD, three classical markers and four isozyme loci. See also, Shoemaker, R. C., RFLP Map of Soybean, p 299-309, in Phillips, R. L. and Vasil, I. K., eds. DNA-Based Markers in Plants, Kluwer Academic Press, Dordrecht, the Netherlands (1994).
SSR technology is currently the most efficient and practical marker technology; more marker loci can be routinely used and more alleles per marker locus can be found using SSRs in comparison to RFLPs. For example, Diwan and Cregan described a highly polymorphic microsatellite locus in soybean with as many as 26 alleles. (Diwan, N. and Cregan, P. B., Theor. Appl. Genet. 95:22-225, 1997.) SNPs may also be used to identify the unique genetic composition of the invention and progeny varieties retaining that unique genetic composition. Various molecular marker techniques may be used in combination to enhance overall resolution.
Molecular markers, which includes markers identified through the use of techniques such as Isozyme Electrophoresis, RFLPs, RAPDs, AP-PCR, DAF, SCARs, AFLPs, SSRs, and SNPs, may be used in plant breeding. One use of molecular markers is Quantitative Trait Loci (QTL) mapping. QTL mapping is the use of markers which are known to be closely linked to alleles that have measurable effects on a quantitative trait. Selection in the breeding process is based upon the accumulation of markers linked to the positive effecting alleles and/or the elimination of the markers linked to the negative effecting alleles from the plant's genome.
Molecular markers can also be used during the breeding process for the selection of qualitative traits. For example, markers closely linked to alleles or markers containing sequences within the actual alleles of interest can be used to select plants that contain the alleles of interest during a backcrossing breeding program. For example, molecular markers are used in soybean breeding for selection of the trait of resistance to soybean cyst nematode, see U.S. Pat. No. 6,162,967. The markers can also be used to select toward the genome of the recurrent parent and against the markers of the donor parent. This procedure attempts to minimize the amount of genome from the donor parent that remains in the selected plants. It can also be used to reduce the number of crosses back to the recurrent parent needed in a backcrossing program. The use of molecular markers in the selection process is often called Genetic Marker-Enhanced Selection or Marker-Assisted Selection. Molecular markers may also be used to identify and exclude certain sources of germplasm as parental varieties or ancestors of a plant by providing a means of tracking genetic profiles through crosses.
Mutation breeding is another method of introducing new traits into field pea varieties. Mutations that occur spontaneously or are artificially induced can be useful sources of variability for a plant breeder. The goal of artificial mutagenesis is to increase the rate of mutation for a desired characteristic. Mutation rates can be increased by many different means including temperature, long-term seed storage, tissue culture conditions, radiation (such as X-rays, Gamma rays, neutrons, Beta radiation, or ultraviolet radiation), chemical mutagens (such as base analogues like 5-bromo-uracil), antibiotics, alkylating agents (such as sulfur mustards, nitrogen mustards, epoxides, ethyleneamines, sulfates, sulfonates, sulfones, or lactones), azide, hydroxylamine, nitrous acid or acridines. Once a desired trait is observed through mutagenesis the trait may then be incorporated into existing germplasm by traditional breeding techniques. Details of mutation breeding can be found in “Principles of Cultivar Development” by Fehr, Macmillan Publishing Company, 1993.
The production of double haploids can also be used for the development of homozygous varieties in a breeding program. Double haploids are produced by the doubling of a set of chromosomes from a heterozygous plant to produce a completely homozygous individual. For example, see Wan et al., Theor. Appl. Genet., 77:889-892, 1989
Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr, 1987).
Proper testing should detect any major faults and establish the level of superiority or improvement over current cultivars. In addition to showing superior performance, there must be a demand for a new cultivar that is compatible with industry standards or which creates a new market. The introduction of a new cultivar will incur additional costs to the seed producer, the grower, processor and consumer; for special advertising and marketing, altered seed and commercial production practices, and new product utilization. The testing preceding release of a new cultivar should take into consideration research and development costs as well as technical superiority of the final cultivar. For seed-propagated cultivars, it must be feasible to produce seed easily and economically.
SUMMARY OF THE INVENTION
According to the invention, there is provided a new field pea cultivar designated CDC 0007. This invention thus relates to the seeds of field pea cultivar CDC 0007, to the plants of field pea cultivar CDC 0007 and to methods for producing a field pea plant produced by crossing the field pea cultivar CDC 0007 with itself or another field pea cultivar, and the creation of variants by mutagenesis or transformation of field pea cultivar CDC 0007.
Thus, any such methods using the field pea cultivar CDC 0007 are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using field pea cultivar CDC 0007 as at least one parent are within the scope of this invention. Advantageously, this field pea cultivar could be used in crosses with other, different, field pea plants to produce first generation (F1) field pea hybrid seeds and plants with superior characteristics.
In another aspect, the present invention provides for single or multiple gene converted plants of field pea cultivar CDC 0007. The transferred gene(s) may preferably be a dominant or recessive allele. Preferably, the transferred gene(s) will confer such traits as herbicide resistance, insect resistance, resistance for bacterial, fungal, or viral disease, male fertility, male sterility, enhanced nutritional quality, and industrial usage. The gene may be a naturally occurring field pea gene or a transgene introduced through genetic engineering techniques.
In another aspect, the present invention provides regenerable cells for use in tissue culture of field pea plant CDC 0007. The tissue culture will preferably be capable of regenerating plants having the physiological and morphological characteristics of the foregoing field pea plant, and of regenerating plants having substantially the same genotype as the foregoing field pea plant. Preferably, the regenerable cells in such tissue cultures will be embryos, protoplasts, meristematic cells, callus, pollen, leaves, anthers, roots, root tips, flowers, seeds, pods or stems. Still further, the present invention provides field pea plants regenerated from the tissue cultures of the invention.
DEFINITIONS
In the description and tables which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:
Allele. Allele is any of one or more alternative forms of a gene, all of which relate to one trait or characteristic. In a diploid cell or organism, the two alleles of a given gene occupy corresponding loci on a pair of homologous chromosomes.
Backcrossing. Backcrossing is a process in which a breeder repeatedly crosses hybrid progeny back to one of the parents, for example, a first generation hybrid F1 with one of the parental genotypes of the F1 hybrid.
Cotyledon. A cotyledon is a type of seed leaf. The cotyledon contains the food storage tissues of the seed.
Embryo. The embryo is the small plant contained within a mature seed.
Emergence. This score indicates the ability of the seed to emerge when planted 3′′ deep in sand and with a controlled temperature of 25° C. The number of plants that emerge each day are counted. Based on this data, each genotype is given a 1 to 9 score based on its rate of emergence and percent of emergence. A score of 9 indicates an excellent rate and percent of emergence, an intermediate score of 5 indicates average ratings and a 1 score indicates a very poor rate and percent of emergence.
Hilum. This refers to the scar left on the seed which marks the place where the seed was attached to the pod prior to the seed being harvested.
Hypocotyl. A hypocotyl is the portion of an embryo or seedling between the cotyledons and the root. Therefore, it can be considered a transition zone between shoot and root.
Lodging Resistance. Lodging resistance is measured on a subjective scale of very good (VG), good (G), fair (F) and poor (P).
Phenotypic Score. The Phenotypic Score is a visual rating of general appearance of the cultivar. All visual traits are considered in the score including healthiness, standability, appearance and freedom from disease. Ratings are scored from 1 being poor to 9 being excellent.
Plant Height. Plant height is taken from the top of the soil to the top node of the plant and is measured in centimeters.
Pod. This refers to the fruit of a field pea plant. It consists of the hull or shell (pericarp) and the field pea seeds.
Protein Percent. Field pea seeds contain a considerable amount of protein. Protein is generally measured by NIR spectrophotometry, and is reported on an as is percentage basis.
Quantitative Trait Loci (QTL). Quantitative trait loci (QTL) refer to genetic loci that control to some degree numerically representable traits that are usually continuously distributed.
Regeneration. Regeneration refers to the development of a plant from tissue culture.
Relative maturity. “Early maturity” is defined as being around 80 days, “medium maturity” is defined as being 90-92 days and “late maturity” is defined as 98 days and beyond.
Seed Protein Peroxidase Activity. Seed protein peroxidase activity refers to a chemical taxonomic technique to separate cultivars based on the presence or absence of the peroxidase enzyme in the seed coat. There are two types of field pea cultivars: those having high peroxidase activity (dark red color) and those having low peroxidase activity (no color).
Seeds per Pound. Field pea seeds vary in seed size, therefore, the number of seeds required to make up one pound also varies. This affects the pounds of seed required to plant a given area and can also impact end uses.
Single Gene Converted (Conversion). Single gene converted (conversion) plant refers to plants which are developed by a plant breeding technique called backcrossing wherein essentially all of the desired morphological and physiological characteristics of a cultivar are recovered in addition to the single gene transferred into the cultivar via the backcrossing technique or via genetic engineering.
Stem vine length. Stem vine length is measured in centimeters from the stem of the plant to the ground and is observed after flowering when pods are fully swollen.
Time of flowering. Time of flowering is observed when approximately 30% of plants have one flower open.


DETAILED DESCRIPTION OF THE INVENTION
Field pea cultivar CDC 0007 is a yellow field pea with medium-range relative maturity under Saskatoon, Saskatchewan, Canada location conditions.
The cultivar has shown uniformity and stability, as described in the following cultivar description information. It has been self-pollinated a sufficient number of generations with careful attention to uniformity of plant type. The cultivar has been increased with continued observation for uniformity.
Field pea cultivar CDC 0007 has the following morphologic and other characteristics (based primarily on data collected at Saskatoon, Saskatchewan, Canada).







TABLE 1





CULTIVAR DESCRIPTION INFORMATION
















Plant type:
Yellow field pea


Plant habit:
Between determinate



and interdeterminate



(between tall and



bushy)


Plant height:
Greater than 50 cm


Stem vine length:
80 cm


Stem fasciation:
Absent


Presence of leaflets:
Semi-leafless


Relative maturity:
Medium (90-92 days)


Flower color:
White


Flower color wing:
White


Flower shape of base:
Level or straight


Time of flowering:
Medium


Protein content:
24%


Stipule:


Development:
Normal


Marbling (before flowering):
Present


Maxium density of marbling:
Between sparse



and medium


Pod:


Length (observe at first flowering node):
Medium


Width (observe at first flowering node):
Medium


Curvature (when fully swollen):
Absent


Color (immature):
Light Green


Color (when fully swollen):
Green


Parchment (when dry and papery):
Entirely present


Shape of distal part (when fully swollen):
Blunt


Seed:


Shape:
Spherical


Size:
Medium


Weight (g/1000 seed):
230


Color of cotyledon:
Yellow


Black color of hilum:
Absent


Time of maturity:
Medium


Reaction to Diseases:


Root Rot (Fusarium oxysporum f. sp pisi):
Moderately susceptible


Mycosphaerella blight (Mycosphaerella pinodes):
Moderately susceptible


Ascochyta root rot (Phoma medicaginis
Moderately susceptible


var. pinodella):


Powdery mildew (Erysiphe polygoni):
Resistant









This invention is also directed to methods for producing a field pea plant by crossing a first parent field pea plant with a second parent field pea plant, wherein the first or second field pea plant is the field pea plant from the field pea cultivar CDC 0007. Further, both first and second parent field pea plants may be from cultivar CDC 0007. Therefore, any methods using field pea cultivar CDC 0007 are part of this invention: selfing, backcrosses, hybrid breeding, and crosses to populations. Any plants produced using field pea cultivar CDC 0007 as at least one parent are within the scope of this invention.
Useful methods include but are not limited to expression vectors introduced into plant tissues using a direct gene transfer method such as microprojectile-mediated delivery, DNA injection, electroporation and the like. More preferably expression vectors are introduced into plant tissues by using either microprojectile-mediated delivery with a biolistic device, or by using Agrobacterium-mediated transformation. Transformant plants obtained with the protoplasm of the invention are intended to be within the scope of this invention.
Field pea cultivar CDC 0007 is similar to field pea cultivar CDC Mozart. While similar to field pea cultivar CDC Mozart, there are significant differences including: field pea cultivar CDC 0007 has a stem vine length of 80 cm while field pea cultivar CDC Mozart has a stem vine length of 70 cm. Field pea cultivar CDC 0007 has a level or straight shape of flower base while field pea cultivar CDC Mozart has an arched (2 lobes) shape of flower base. In addition, field pea cultivar CDC 0007 has better lodging resistance than soybean cultivar CDC Mozart.
FURTHER EMBODIMENTS OF THE INVENTION
With the advent of molecular biological techniques that have allowed the isolation and characterization of genes that encode specific protein products, scientists in the field of plant biology developed a strong interest in engineering the genome of plants to contain and express foreign genes, or additional, or modified versions of native, or endogenous, genes (perhaps driven by different promoters) in order to alter the traits of a plant in a specific manner. Such foreign additional and/or modified genes are referred to herein collectively as “transgenes”. Over the last fifteen to twenty years several methods for producing transgenic plants have been developed and the present invention, in particular embodiments, also relates to transformed versions of the claimed cultivar or line.
Plant transformation involves the construction of an expression vector which will function in plant cells. Such a vector comprises DNA comprising a gene under control of, or operatively linked to, a regulatory element (for example, a promoter). The expression vector may contain one or more such operably linked gene/regulatory element combinations. The vector(s) may be in the form of a plasmid and can be used alone or in combination with other plasmids to provide transformed field pea plants using transformation methods as described below to incorporate transgenes into the genetic material of the field pea plant(s).
Expression Vectors for Field Pea Transformation: Marker Genes
Expression vectors include at least one genetic marker operably linked to a regulatory element (a promoter, for example) that allows transformed cells containing the marker to be either recovered by negative selection, i.e., inhibiting growth of cells that do not contain the selectable marker gene, or by positive selection, i.e., screening for the product encoded by the genetic marker. Many commonly used selectable marker genes for plant transformation are well known in the transformation arts, and include, for example, genes that code for enzymes that metabolically detoxify a selective chemical agent which may be an antibiotic or an herbicide, or genes that encode an altered target which is insensitive to the inhibitor. A few positive selection methods are also known in the art.
One commonly used selectable marker gene for plant transformation is the neomycin phosphotransferase II (nptII) gene which, when under the control of plant regulatory signals, confers resistance to kanamycin. Fraley et al., Proc. Natl. Acad. Sci. U.S.A., 80:4803 (1983). Another commonly used selectable marker gene is the hygromycin phosphotransferase gene which confers resistance to the antibiotic hygromycin. Vanden Elzen et al., Plant Mol. Biol., 5:299 (1985).
Additional selectable marker genes of bacterial origin that confer resistance to antibiotics include gentamycin acetyl transferase, streptomycin phosphotransferase, and aminoglycoside-3′-adenyl transferase, the bleomycin resistance determinant. Hayford et al., Plant Physiol. 86:1216 (1988), Jones et al., Mol. Gen. Genet., 210:86 (1987), Svab et al., Plant Mol. Biol. 14:197 (1990), Hille et al., Plant Mol. Biol. 7:171 (1986). Other selectable marker genes confer resistance to herbicides such as glyphosate, glufosinate or bromoxynil. Comai et al., Nature 317:741-744 (1985), Gordon-Kamm et al., Plant Cell 2:603-618 (1990) and Stalker et al., Science 242:419-423 (1988).
Selectable marker genes for plant transformation not of bacterial origin include, for example, mouse dihydrofolate reductase, plant 5-enolpyruvylshikimate-3-phosphate synthase and plant acetolactate synthase. Eichholtz et al., Somatic Cell Mol. Genet. 13:67 (1987), Shah et al., Science 233:478 (1986), Charest et al., Plant Cell Rep. 8:643 (1990).
Another class of marker genes for plant transformation requires screening of presumptively transformed plant cells rather than direct genetic selection of transformed cells for resistance to a toxic substance such as an antibiotic. These genes are particularly useful to quantify or visualize the spatial pattern of expression of a gene in specific tissues and are frequently referred to as reporter genes because they can be fused to a gene or gene regulatory sequence for the investigation of gene expression. Commonly used genes for screening presumptively transformed cells include β-glucuronidase (GUS), β-galactosidase, luciferase and chloramphenicol acetyltransferase. Jefferson, R. A., Plant Mol. Biol. Rep. 5:387 (1987), Teeri et al., EMBO J. 8:343 (1989), Koncz et al., Proc. Natl. Acad. Sci. U.S.A. 84:131 (1987), DeBlock et al., EMBO J. 3:1681 (1984).
In vivo methods for visualizing GUS activity that do not require destruction of plant tissue are available. Molecular Probes publication 2908, Imagene GreenTM, p. 1-4 (1993) and Naleway et al., J. Cell Biol. 115:151a (1991). However, these in vivo methods for visualizing GUS activity have not proven useful for recovery of transformed cells because of low sensitivity, high fluorescent backgrounds and limitations associated with the use of luciferase genes as selectable markers.
More recently, a gene encoding Green Fluorescent Protein (GFP) has been utilized as a marker for gene expression in prokaryotic and eukaryotic cells. Chalfie et al., Science 263:802 (1994). GFP and mutants of GFP may be used as screenable markers.
Expression Vectors for Field Pea Transformation: Promoters
Genes included in expression vectors must be driven by nucleotide sequence comprising a regulatory element, for example, a promoter. Several types of promoters are now well known in the transformation arts, as are other regulatory elements that can be used alone or in combination with promoters.
As used herein, “promoter” includes reference to a region of DNA upstream from the start of transcription and involved in recognition and binding of RNA polymerase and other proteins to initiate transcription. A “plant promoter” is a promoter capable of initiating transcription in plant cells. Examples of promoters under developmental control include promoters that preferentially initiate transcription in certain tissues, such as leaves, roots, seeds, fibers, xylem vessels, tracheids, or sclerenchyma. Such promoters are referred to as “tissue-preferred”. Promoters which initiate transcription only in a certain tissue are referred to as “tissue-specific”. A “cell type” specific promoter primarily drives expression in certain cell types in one or more organs, for example, vascular cells in roots or leaves. An “inducible” promoter is a promoter which is under environmental control. Examples of environmental conditions that may effect transcription by inducible promoters include anaerobic conditions or the presence of light. Tissue-specific, tissue-preferred, cell type specific, and inducible promoters constitute the class of “non-constitutive” promoters. A “constitutive” promoter is a promoter which is active under most environmental conditions.
A. Inducible Promoters—An inducible promoter is operably linked to a gene for expression in field pea. Optionally, the inducible promoter is operably linked to a nucleotide sequence encoding a signal sequence which is operably linked to a gene for expression in field pea. With an inducible promoter the rate of transcription increases in response to an inducing agent.
Any inducible promoter can be used in the instant invention. See Ward et al., Plant Mol. Biol. 22:361-366 (1993). Exemplary inducible promoters include, but are not limited to, that from the ACEI system which responds to copper (Mett et al., PNAS 90:4567-4571 (1993)); In2 gene from maize which responds to benzenesulfonamide herbicide safeners (Hershey et al., Mol. Gen. Genetics 227:229-237 (1991) and Gatz et al., Mol. Gen. Genetics 243:32-38 (1994)) or Tet repressor from Tn10 (Gatz et al., Mol. Gen. Genetics 227:229-237 (1991)). A particularly preferred inducible promoter is a promoter that responds to an inducing agent to which plants do not normally respond. An exemplary inducible promoter is the inducible promoter from a steroid hormone gene, the transcriptional activity of which is induced by a glucocorticosteroid hormone (Schena et al., Proc. Natl. Acad. Sci. U.S.A. 88:0421 (1991)).
B. Constitutive Promoters—A constitutive promoter is operably linked to a gene for expression in field pea or the constitutive promoter is operably linked to a nucleotide sequence encoding a signal sequence which is operably linked to a gene for expression in field pea.
Many different constitutive promoters can be utilized in the instant invention. Exemplary constitutive promoters include, but are not limited to, the promoters from plant viruses such as the 35S promoter from CaMV (Odell et al., Nature 313:810-812 (1985)) and the promoters from such genes as rice actin (McElroy et al., Plant Cell 2:163-171 (1990)); ubiquitin (Christensen et al., Plant Mol. Biol. 12:619-632 (1989) and Christensen et al., Plant Mol. Biol. 18:675-689 (1992)); pEMU (Last et al., Theor. Appl. Genet 81:581-588 (1991)); MAS (Velten et al., EMBO J. 3:2723-2730 (1984)) and maize H3 histone (Lepetit et al., Mol. Gen. Genetics 231:276-285 (1992) and Atanassova et al., Plant Journal 2 (3): 291-300 (1992)). The ALS promoter, Xba1/NcoI fragment 5′ to the Brassica napus ALS3 structural gene (or a nucleotide sequence similarity to said Xba1/NcoI fragment), represents a particularly useful constitutive promoter. See PCT application WO96/30530.
C. Tissue-specific or Tissue-preferred Promoters—A tissue-specific promoter is operably linked to a gene for expression in field pea. Optionally, the tissue-specific promoter is operably linked to a nucleotide sequence encoding a signal sequence which is operably linked to a gene for expression in field pea. Plants transformed with a gene of interest operably linked to a tissue-specific promoter produce the protein product of the transgene exclusively, or preferentially, in a specific tissue.
Any tissue-specific or tissue-preferred promoter can be utilized in the instant invention. Exemplary tissue-specific or tissue-preferred promoters include, but are not limited to, a root-preferred promoter such as that from the phaseolin gene (Murai et al., Science 23:476-482 (1983) and Sengupta-Gopalan et al., Proc. Natl. Acad. Sci. U.S.A. 82:3320-3324 (1985)); a leaf-specific and light-induced promoter such as that from cab or rubisco (Simpson et al., EMBO J. 4(11):2723-2729 (1985) and Timko et al., Nature 318:579-582 (1985)); an anther-specific promoter such as that from LAT52 (Twell et al., Mol. Gen. Genetics 217:240-245 (1989)); a pollen-specific promoter such as that from Zm13 (Guerrero et al., Mol. Gen. Genetics 244:161-168 (1993)) or a microspore-preferred promoter such as that from apg (Twell et al., Sex. Plant Reprod. 6:217-224 (1993)).
Signal Sequences for Targeting Proteins to Subcellular Compartments
Transport of protein produced by transgenes to a subcellular compartment such as the chloroplast, vacuole, peroxisome, glyoxysome, cell wall or mitochondrion or for secretion into the apoplast, is accomplished by means of operably linking the nucleotide sequence encoding a signal sequence to the 5′ and/or 3′ region of a gene encoding the protein of interest. Targeting sequences at the 5′ and/or 3′ end of the structural gene may determine during protein synthesis and processing where the encoded protein is ultimately compartmentalized.
The presence of a signal sequence directs a polypeptide to either an intracellular organelle or subcellular compartment or for secretion to the apoplast. Many signal sequences are known in the art. See, for example Becker et al., Plant Mol. Biol. 20:49 (1992); Close, P. S., Master's Thesis, Iowa State University (1993); Knox, C., et al., Plant Mol. Biol. 9:3-17 (1987); Lerner et al., Plant Physiol. 91:124-129 (1989); Fontes et al., Plant Cell 3:483-496 (1991); Matsuoka et al., Proc. Natl. Acad. Sci. 88:834 (1991); Gould et al., J. Cell. Biol. 108:1657 (1989); Creissen et al., Plant J. 2:129 (1991); Kalderon, et al., Cell 39:499-509 (1984); Steifel, et al., Plant Cell 2:785-793 (1990).
Foreign Protein Genes and Agronomic Genes
With transgenic plants according to the present invention, a foreign protein can be produced in commercial quantities. Thus, techniques for the selection and propagation of transformed plants, which are well understood in the art, yield a plurality of transgenic plants which are harvested in a conventional manner, and a foreign protein then can be extracted from a tissue of interest or from total biomass. Protein extraction from plant biomass can be accomplished by known methods which are discussed, for example, by Heney and Orr, Anal. Biochem. 114:92-6 (1981).
According to a preferred embodiment, the transgenic plant provided for commercial production of foreign protein is a field pea plant. In another preferred embodiment, the biomass of interest is seed. For the relatively small number of transgenic plants that show higher levels of expression, a genetic map can be generated, primarily via conventional RFLP, PCR and SSR analysis, which identifies the approximate chromosomal location of the integrated DNA molecule. For exemplary methodologies in this regard, see Glick and Thompson, Methods in Plant Molecular Biology and Biotechnology, CRC Press, Boca Raton 269:284 (1993). Map information concerning chromosomal location is useful for proprietary protection of a subject transgenic plant. If unauthorized propagation is undertaken and crosses made with other germplasm, the map of the integration region can be compared to similar maps for suspect plants, to determine if the latter have a common parentage with the subject plant. Map comparisons would involve hybridizations, RFLP, PCR, SSR and sequencing, all of which are conventional techniques.
Likewise, by means of the present invention, agronomic genes can be expressed in transformed plants. More particularly, plants can be genetically engineered to express various phenotypes of agronomic interest. Exemplary genes implicated in this regard include, but are not limited to, those categorized below:
1. Genes That Confer Resistance to Pests or Disease and That Encode:
A. Plant disease resistance genes. Plant defenses are often activated by specific interaction between the product of a disease resistance gene (R) in the plant and the product of a corresponding avirulence (Avr) gene in the pathogen. A plant cultivar can be transformed with one or more cloned resistance genes to engineer plants that are resistant to specific pathogen strains. See, for example Jones et al., Science 266:789 (1994) (cloning of the tomato Cf-9 gene for resistance to Cladosporium fulvum); Martin et al., Science 262:1432 (1993) (tomato Pto gene for resistance to Pseudomonas syringae pv. tomato encodes a protein kinase); Mindrinos et al., Cell 78:1089 (1994) (Arabidopsis RSP2 gene for resistance to Pseudomonas syringae).
B. A gene conferring resistance to a pest, such as soybean cyst nematode. See e.g., PCT Application WO96/30517; PCT Application WO93/19181.
C. A Bacillus thuringiensis protein, a derivative thereof or a synthetic polypeptide modeled thereon. See, for example, Geiser et al., Gene 48:109 (1986), who disclose the cloning and nucleotide sequence of a Bt-δ-endotoxin gene. Moreover, DNA molecules encoding δ-endotoxin genes can be purchased from American Type Culture Collection, Manassas, Va., for example, under ATCC Accession Nos. 40098, 67136, 31995 and 31998.
D. A lectin. See, for example, the disclosure by Van Damme et al., Plant Molec. Biol. 24:25 (1994), of the nucleotide sequences of several Clivia miniata mannose-binding lectin genes.
E. A vitamin-binding protein such as avidin. See PCT application US93/06487.
The application teaches the use of avidin and avidin homologues as larvicides against insect pests.
F. An enzyme inhibitor, for example, a protease or proteinase inhibitor or an amylase inhibitor. See, for example, Abe et al., J. Biol. Chem. 262:16793 (1987) (nucleotide sequence of rice cysteine proteinase inhibitor); Huub et al., Plant Molec. Biol. 21:985 (1993) (nucleotide sequence of cDNA encoding tobacco proteinase inhibitor I); Sumitani et al., Biosci. Biotech. Biochem. 57:1243 (1993) (nucleotide sequence of Streptomyces nitrosporeus α-amylase inhibitor) and U.S. Pat. No. 5,494,813 (Hepher and Atkinson, issued Feb. 27, 1996).
G. An insect-specific hormone or pheromone such as an ecdysteroid or juvenile hormone, variants thereof, mimetics based thereon, or antagonists or agonists thereof. See, for example, the disclosure by Hammock et al., Nature 344:458 (1990), of baculovirus expression of cloned juvenile hormone esterase, an inactivator of juvenile hormone.
H. An insect-specific peptide or neuropeptide which, upon expression, disrupts the physiology of the affected pest. For example, see the disclosures of Regan, J. Biol. Chem. 269:9 (1994) (expression cloning yields DNA coding for insect diuretic hormone receptor), and Pratt et al., Biochem. Biophys. Res. Comm. 163:1243 (1989) (an allostatin is identified in Diploptera puntata). See also U.S. Pat. No. 5,266,317 to Tomalski et al., which discloses genes encoding insect-specific, paralytic neurotoxins.
I. An insect-specific venom produced in nature by a snake, a wasp, etc. For example, see Pang et al., Gene 116:165 (1992), for disclosure of heterologous expression in plants of a gene coding for a scorpion insectotoxic peptide.
J. An enzyme responsible for a hyperaccumulation of a monoterpene, a sesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid derivative or another non-protein molecule with insecticidal activity.
K. An enzyme involved in the modification, including the post-translational modification, of a biologically active molecule; for example, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme, a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, a phosphatase, a kinase, a phosphorylase, a polymerase, an elastase, a chitinase and a glucanase, whether natural or synthetic. See PCT application WO 93/02197 in the name of Scott et al., which discloses the nucleotide sequence of a callase gene. DNA molecules which contain chitinase-encoding sequences can be obtained, for example, from the ATCC under Accession Nos. 39637 and 67152. See also Kramer et al., Insect Biochem. Molec. Biol. 23:691 (1993), who teach the nucleotide sequence of a cDNA encoding tobacco hornworm chitinase, and Kawalleck et al., Plant Molec. Biol. 21:673 (1993), who provide the nucleotide sequence of the parsley ubi4-2 polyubiquitin gene.
L. A molecule that stimulates signal transduction. For example, see the disclosure by Botella et al., Plant Molec. Biol. 24:757 (1994), of nucleotide sequences for mung bean calmodulin cDNA clones, and Griess et al., Plant Physiol. 104:1467 (1994), who provide the nucleotide sequence of a maize calmodulin cDNA clone.
M. A hydrophobic moment peptide. See PCT application WO95/16776 (disclosure of peptide derivatives of tachyplesin which inhibit fungal plant pathogens) and PCT application WO95/18855 (teaches synthetic antimicrobial peptides that confer disease resistance).
N. A membrane permease, a channel former or a channel blocker. For example, see the disclosure of Jaynes et al., Plant Sci 89:43 (1993), of heterologous expression of a cecropin-β lytic peptide analog to render transgenic tobacco plants resistant to Pseudomonas solanacearum. 
O. A viral-invasive protein or a complex toxin derived therefrom. For example, the accumulation of viral coat proteins in transformed plant cells imparts resistance to viral infection and/or disease development effected by the virus from which the coat protein gene is derived, as well as by related viruses. See Beachy et al., Ann. Rev. Phytopathol. 28:451 (1990). Coat protein-mediated resistance has been conferred upon transformed plants against alfalfa mosaic virus, cucumber mosaic virus, tobacco streak virus, potato virus X, potato virus Y, tobacco etch virus, tobacco rattle virus and tobacco mosaic virus. Id.
P. An insect-specific antibody or an immunotoxin derived therefrom. Thus, an antibody targeted to a critical metabolic function in the insect gut would inactivate an affected enzyme, killing the insect. Cf. Taylor et al., Abstract #497, Seventh Int'l Symposium on Molecular Plant-Microbe Interactions (Edinburgh, Scotland) (1994) (enzymatic inactivation in transgenic tobacco via production of single-chain antibody fragments).
Q. A virus-specific antibody. See, for example, Tavladoraki et al., Nature 366:469 (1993), who show that transgenic plants expressing recombinant antibody genes are protected from virus attack.
R. A developmental-arrestive protein produced in nature by a pathogen or a parasite. Thus, fungal endo-α-1,4-D-polygalacturonases facilitate fungal colonization and plant nutrient release by solubilizing plant cell wall homo-α-1, 4-D-galacturonase. See Lamb et al., Bio/Technology 10:1436 (1992). The cloning and characterization of a gene which encodes a bean endopolygalacturonase-inhibiting protein is described by Toubart et al., Plant J. 2:367 (1992).
S. A developmental-arrestive protein produced in nature by a plant. For example, Logemann et al., Bio/Technology 10:305 (1992), have shown that transgenic plants expressing the barley ribosome-inactivating gene have an increased resistance to fungal disease.
T. Genes involved in the Systemic Acquired Resistance (SAR) Response and/or the pathogenesis-related genes. Briggs, S. Current Biology, 5(2) (1995).
U. Antifungal genes. See Cornelissen and Melchers, Plant Physiol., 101:709-712 (1993); Parijs et al., Planta 183:258-264 (1991) and Bushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998).
2. Genes That Confer Resistance to an Herbicide, For Example:
A. An herbicide that inhibits the growing point or meristem, such as an imidazolinone or a sulfonylurea. Exemplary genes in this category code for mutant ALS and AHAS enzyme as described, for example, by Lee et al., EMBO J. 7:1241 (1988), and Miki et al., Theor. Appl. Genet. 80:449 (1990), respectively.
B. Glyphosate (resistance conferred by mutant 5-enolpyruvishikimate-3-phosphate synthase (EPSP) and aroA genes, respectively) and other phosphono compounds such as glufosinate (phosphinothricin acetyl transferase (PAT) and Streptomyces hygroscopicus PAT, bar, genes), and pyridinoxy or phenoxy proprionic acids and cyclohexones (ACCase inhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 to Shah, et al., which discloses the nucleotide sequence of a form of EPSP which can confer glyphosate resistance. A DNA molecule encoding a mutant aroA gene can be obtained under ATCC accession number 39256, and the nucleotide sequence of the mutant gene is disclosed in U.S. Pat. No. 4,769,061 to Comai. European patent application No. 0 333 033 to Kumada et al., and U.S. Pat. No. 4,975,374 to Goodman et al., disclose nucleotide sequences of glutamine synthetase genes which confer resistance to herbicides such as L-phosphinothricin. The nucleotide sequence of a PAT gene is provided in European application No. 0 242 246 to Leemans et al. DeGreef et al., Bio/Technology 7:61 (1989), describe the production of transgenic plants that express chimeric bar genes coding for phosphinothricin acetyl transferase activity. Exemplary of genes conferring resistance to phenoxy proprionic acids and cyclohexones, such as sethoxydim and haloxyfop are the Acc1-S1, Acc1-S2 and Acc1-S3 genes described by Marshall et al., Theor. Appl. Genet. 83:435 (1992).
C. An herbicide that inhibits photosynthesis, such as a triazine (psbA and gs+genes) or a benzonitrile (nitrilase gene). Przibila et al., Plant Cell 3:169 (1991), describe the transformation of Chlamydomonas with plasmids encoding mutant psbA genes. Nucleotide sequences for nitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, and DNA molecules containing these genes are available under ATCC Accession Nos. 53435, 67441, and 67442. Cloning and expression of DNA coding for a glutathione S-transferase is described by Hayes et al., Biochem. J. 285:173 (1992).
D. Acetohydroxy acid synthase, which has been found to make plants that express this enzyme resistant to multiple types of herbicides, has been introduced into a variety of plants. See Hattori et al., Mol. Gen. Genet. 246:419, 1995. Other genes that confer tolerance to herbicides include a gene encoding a chimeric protein of rat cytochrome P4507A1 and yeast NADPH-cytochrome P450 oxidoreductase (Shiota et al., Plant Physiol., 106:17, 1994), genes for glutathione reductase and superoxide dismutase (Aono et al., Plant Cell Physiol. 36:1687, 1995), and genes for various phosphotransferases (Datta et al., Plant Mol. Biol. 20:619, 1992).
E. Protoporphyrinogen oxidase (protox) is necessary for the production of chlorophyll, which is necessary for all plant survival. The protox enzyme serves as the target for a variety of herbicidal compounds. These herbicides also inhibit growth of all the different species of plants present, causing their total destruction. The development of plants containing altered protox activity which are resistant to these herbicides are described in U.S. Pat. Nos. 6,288,306; 6,282,837; 5,767,373; and international publication WO 01/12825.
3. Genes That Confer or Contribute to a Value-Added Trait, Such as:
A. Modified fatty acid metabolism, for example, by transforming a plant with an antisense gene of stearyl-ACP desaturase to increase stearic acid content of the plant. See Knultzon et al., Proc. Natl. Acad. Sci. U.S.A. 89:2624 (1992).
B. Decreased phytate content-1) Introduction of a phytase-encoding gene would enhance breakdown of phytate, adding more free phosphate to the transformed plant. For example, see Van Hartingsveldt et al., Gene 127:87 (1993), for a disclosure of the nucleotide sequence of an Aspergillus niger phytase gene. 2) A gene could be introduced that reduced phytate content. In maize for example, this could be accomplished by cloning and then reintroducing DNA associated with the single allele which is responsible for maize mutants characterized by low levels of phytic acid. See Raboy et al., Maydica 35:383 (1990).
C. Modified carbohydrate composition effected, for example, by transforming plants with a gene coding for an enzyme that alters the branching pattern of starch. See Shiroza et al., J. Bacteol. 170:810 (1988) (nucleotide sequence of Streptococcus mutants fructosyltransferase gene); Steinmetz et al., Mol. Gen. Genet. 20:220 (1985) (nucleotide sequence of Bacillus subtilis levansucrase gene); Pen et al., Bio/Technology 10:292 (1992) (production of transgenic plants that express Bacillus licheniformis α-amylase); Elliot et al., Plant Molec. Biol. 21:515 (1993) (nucleotide sequences of tomato invertase genes); Søgaard et al., J. Biol. Chem. 268:22480 (1993) (site-directed mutagenesis of barley α-amylase gene), and Fisher et al., Plant Physiol. 102:1045 (1993) (maize endosperm starch branching enzyme II).
Methods for Field Pea Transformation
Numerous methods for plant transformation have been developed, including biological and physical plant transformation protocols. See, for example, Miki et al., “Procedures for Introducing Foreign DNA into Plants” in Methods in Plant Molecular Biology and Biotechnology, Glick B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages 67-88. In addition, expression vectors and in vitro culture methods for plant cell or tissue transformation and regeneration of plants are available. See, for example, Gruber et al., “Vectors for Plant Transformation” in Methods in Plant Molecular Biology and Biotechnology, Glick B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pages 89-119.
A. Agrobacterium-mediated Transformation—One method for introducing an expression vector into plants is based on the natural transformation system of Agrobacterium. See, for example, Horsch et al., Science 227:1229 (1985). A. tumefaciens and A. rhizogenes are plant pathogenic soil bacteria which genetically transform plant cells. The Ti and Ri plasmids of A. tumefaciens and A. rhizogenes, respectively, carry genes responsible for genetic transformation of the plant. See, for example, Kado, C. I., Crit. Rev. Plant Sci. 10:1 (1991). Descriptions of Agrobacterium vector systems and methods for Agrobacterium-mediated gene transfer are provided by Gruber et al., supra, Miki et al., supra, and Moloney et al., Plant Cell Reports 8:238 (1989). See also, U.S. Pat. No. 5,563,055 (Townsend and Thomas), issued Oct. 8, 1996.
B. Direct Gene Transfer—Several methods of plant transformation, collectively referred to as direct gene transfer, have been developed as an alternative to Agrobacterium-mediated transformation. A generally applicable method of plant transformation is microprojectile-mediated transformation wherein DNA is carried on the surface of microprojectiles measuring 1 to 4 μm. The expression vector is introduced into plant tissues with a biolistic device that accelerates the microprojectiles to speeds of 300 to 600 m/s which is sufficient to penetrate plant cell walls and membranes. Sanford et al., Part. Sci. Technol. 5:27 (1987); Sanford, J. C., Trends Biotech. 6:299 (1988); Klein et al., Bio/Technology 6:559-563 (1988); Sanford, J. C., Physiol Plant 7:206 (1990); Klein et al., Biotechnology 10:268 (1992). See also U.S. Pat. No. 5,015,580 (Christou, et al.), issued May 14, 1991; U.S. Pat. No. 5,322,783 (Tomes, et al), issued Jun. 21, 1994.
Another method for physical delivery of DNA to plants is sonication of target cells. Zhang et al., Bio/Technology 9:996 (1991). Alternatively, liposome and spheroplast fusion have been used to introduce expression vectors into plants. Deshayes et al., EMBO J., 4:2731 (1985), Christou et al., Proc Natl. Acad. Sci. U.S.A. 84:3962 (1987). Direct uptake of DNA into protoplasts using CaCl2 precipitation, polyvinyl alcohol or poly-L-ornithine has also been reported. Hain et al., Mol. Gen. Genet 199:161 (1985) and Draper et al., Plant Cell Physiol. 23:451 (1982). Electroporation of protoplasts and whole cells and tissues have also been described. Donn et al., In Abstracts of VIIth International Congress on Plant Cell and Tissue Culture IAPTC, A2-38, p 53 (1990); D'Halluin et al., Plant Cell 4:1495-1505 (1992) and Spencer et al., Plant Mol. Biol. 24:51-61 (1994).
Following transformation of field pea target tissues, expression of the above-described selectable marker genes allows for preferential selection of transformed cells, tissues and/or plants, using regeneration and selection methods now well known in the art.
The foregoing methods for transformation would typically be used for producing a transgenic cultivar. The transgenic cultivar could then be crossed with another (non-transformed or transformed) cultivar, in order to produce a new transgenic cultivar. Alternatively, a genetic trait which has been engineered into a particular field pea line using the foregoing transformation techniques could be moved into another line using traditional backcrossing techniques that are well known in the plant breeding arts. For example, a backcrossing approach could be used to move an engineered trait from a public, non-elite cultivar into an elite cultivar, or from a cultivar containing a foreign gene in its genome into a cultivar or cultivars which do not contain that gene. As used herein, “crossing” can refer to a simple X by Y cross, or the process of backcrossing, depending on the context.
Single Gene Conversions of Field Pea
When the term field pea plant is used in the context of the present invention, this also includes any single gene conversions of that cultivar. The term single gene converted plant as used herein refers to those field pea plants which are developed by a plant breeding technique called backcrossing wherein essentially all of the desired morphological and physiological characteristics of a cultivar are recovered in addition to the single gene transferred into the cultivar via the backcrossing technique. Backcrossing methods can be used with the present invention to improve or introduce a characteristic into the cultivar. The term backcrossing as used herein refers to the repeated crossing of a hybrid progeny back to the recurrent parent, i.e., crossing back 1, 2, 3, 4, 5, 6, 7, 8, 9 or more times to the recurrent parent. The parental field pea plant which contributes the gene for the desired characteristic is termed the nonrecurrent or donor parent. This terminology refers to the fact that the nonrecurrent parent is used one time in the backcross protocol and therefore does not recur. The parental field pea plant to which the gene or genes from the nonrecurrent parent are transferred is known as the recurrent parent as it is used for several rounds in the backcrossing protocol (Poehlman & Sleper, 1994; Fehr, 1987). In a typical backcross protocol, the original cultivar of interest (recurrent parent) is crossed to a second cultivar (nonrecurrent parent) that carries the single gene of interest to be transferred. The resulting progeny from this cross are then crossed again to the recurrent parent and the process is repeated until a field pea plant is obtained wherein essentially all of the desired morphological and physiological characteristics of the recurrent parent are recovered in the converted plant, in addition to the single transferred gene from the nonrecurrent parent, as determined at the 5% significance level when grown in the same environmental conditions.
The selection of a suitable recurrent parent is an important step for a successful backcrossing procedure. The goal of a backcross protocol is to alter or substitute a single trait or characteristic in the original cultivar. To accomplish this, a single gene of the recurrent cultivar is modified or substituted with the desired gene from the nonrecurrent parent, while retaining essentially all of the rest of the desired genetic, and therefore the desired physiological and morphological, constitution of the original cultivar. The choice of the particular nonrecurrent parent will depend on the purpose of the backcross; one of the major purposes is to add some commercially desirable, agronomically important trait to the plant. The exact backcrossing protocol will depend on the characteristic or trait being altered to determine an appropriate testing protocol. Although backcrossing methods are simplified when the characteristic being transferred is a dominant allele, a recessive allele may also be transferred. In this instance it may be necessary to introduce a test of the progeny to determine if the desired characteristic has been successfully transferred.
Many single gene traits have been identified that are not regularly selected for in the development of a new cultivar but that can be improved by backcrossing techniques. Single gene traits may or may not be transgenic; examples of these traits include but are not limited to, male sterility, waxy starch, herbicide resistance, resistance for bacterial, fungal, or viral disease, insect resistance, male fertility, enhanced nutritional quality, industrial usage, yield stability and yield enhancement. These genes are generally inherited through the nucleus. Several of these single gene traits are described in U.S. Pat. Nos. 5,959,185, 5,973,234 and 5,977,445.
Further reproduction of the cultivar can occur by tissue culture and regeneration. Tissue culture of various plant tissues and regeneration of plants therefrom is well known and widely published. For example, reference may be had to Komatsuda, T. et al., Crop Sci. 31:333-337 (1991); Stephens, P. A., et al., Theor. Appl. Genet (1991) 82:633-635; Komatsuda, T. et al., Plant Cell, Tissue and Organ Culture, 28:103-113 (1992); Dhir, S. et al., Plant Cell Reports (1992) 11:285-289; Pandey, P. et al., Japan J. Breed. 42:1-5 (1992); and Shetty, K., et al., Plant Science 81:245-251 (1992); as well as U.S. Pat. No. 5,024,944 issued Jun. 18, 1991 to Collins et al., and U.S. Pat. No. 5,008,200 issued Apr. 16, 1991 to Ranch et al. Thus, another aspect of this invention is to provide cells which, upon growth and differentiation, produce field pea plants having the physiological and morphological characteristics of field pea cultivar CDC 0007.
As used herein, the term “tissue culture” indicates a composition comprising isolated cells of the same or a different type or a collection of such cells organized into parts of a plant. Exemplary types of tissue cultures are protoplasts, calli, plant clumps, and plant cells that can generate tissue culture that are intact in plants or parts of plants, such as embryos, pollen, flowers, seeds, pods, leaves, stems, roots, root tips, anthers, and the like. Means for preparing and maintaining plant tissue culture are well known in the art. By way of example, a tissue culture comprising organs has been used to produce regenerated plants. See also U.S. Pat. Nos. 5,959,185; 5,973,234 and 5,977,445; Brar, M. S., et al, In Vitro Cell. Deve. Biol.-Plant 35:8-12, January-February, 1999 and Brar, M. S., et al, In Vitro Cell. Deve. Biol.-Plant 35:222-225, May-June, 1999.
This invention also is directed to methods for producing a field pea plant by crossing a first parent field pea plant with a second parent field pea plant wherein the first or second parent field pea plant is a field pea plant of field pea cultivar CDC 0007. Further, both first and second parent field pea plants can come from field pea cultivar CDC 0007. Thus, any such methods using the field pea cultivar CDC 0007 are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using field pea cultivar CDC 0007 as at least one parent are within the scope of this invention, including those developed from varieties derived from field pea cultivar CDC 0007. Advantageously, this field pea cultivar could be used in crosses with other, different, field pea plants to produce first generation (F1) field pea hybrid seeds and plants with superior characteristics. The cultivar of the invention can also be used for transformation where exogenous genes are introduced and expressed by the cultivar of the invention. Genetic variants created either through traditional breeding methods using field pea cultivar CDC 0007 or through transformation of field pea cultivar CDC 0007 by any of a number of protocols known to those of skill in the art are intended to be within the scope of this invention.
The following describes breeding methods that may be used with field pea cultivar CDC 0007 in the development of further field pea plants. One such embodiment is a method for developing a field pea cultivar CDC 0007 progeny field pea plant in a field pea plant breeding program comprising: obtaining the field pea plant, or a part thereof, of field pea cultivar CDC 0007 utilizing said plant or plant part as a source of breeding material and selecting a field pea cultivar CDC 0007 progeny plant with molecular markers in common with field pea cultivar CDC 0007 and/or with morphological and/or physiological characteristics selected from the characteristics listed in Tables 1 or 2. Breeding steps that may be used in the field pea plant breeding program include pedigree breeding, backcrossing, mutation breeding, and recurrent selection. In conjunction with these steps, techniques such as RFLP-enhanced selection, genetic marker enhanced selection (for example SSR markers) and the making of double haploids may be utilized.
Another method involves producing a population of field pea cultivar CDC 0007 progeny field pea plants, comprising crossing field pea cultivar CDC 0007 with another field pea plant, thereby producing a population of field pea plants, which, on average, derive 50% of their alleles from field pea cultivar CDC 0007. A plant of this population may be selected and repeatedly selfed or sibbed with a field pea cultivar resulting from these successive filial generations. One embodiment of this invention is the field pea cultivar produced by this method and that has obtained at least 50% of its alleles from field pea cultivar CDC 0007.
One of ordinary skill in the art of plant breeding would know how to evaluate the traits of two plant varieties to determine if there is no significant difference between the two traits expressed by those varieties. For example, see Fehr and Walt, Principles of Cultivar Development, p 261-286 (1987). Thus the invention includes field pea cultivar CDC 0007 progeny field pea plants comprising a combination of at least two CDC 0007 traits selected from the group consisting of those listed in Tables 1 and 2 or the CDC 0007 combination of traits listed in the Summary of the Invention, so that said progeny field pea plant is not significantly different for said traits than field pea cultivar CDC 0007 as determined at the 5% significance level when grown in the same environmental conditions. Using techniques described herein, molecular markers may be used to identify said progeny plant as an CDC 0007 progeny plant. Mean trait values may be used to determine whether trait differences are significant, and preferably the traits are measured on plants grown under the same environmental conditions. Once such a cultivar is developed its value is substantial since it is important to advance the germplasm base as a whole in order to maintain or improve traits such as yield, disease resistance, pest resistance, and plant performance in extreme environmental conditions.
Progeny of field pea cultivar CDC 0007 may also be characterized through their filial relationship with field pea cultivar CDC 0007, as for example, being within a certain number of breeding crosses of field pea cultivar CDC 0007. A breeding cross is a cross made to introduce new genetics into the progeny, and is distinguished from a cross, such as a self or a sib cross, made to select among existing genetic alleles. The lower the number of breeding crosses in the pedigree, the closer the relationship between field pea cultivar CDC 0007 and its progeny. For example, progeny produced by the methods described herein may be within 1, 2, 3, 4 or 5 breeding crosses of field pea cultivar CDC 0007.
As used herein, the term plant includes plant cells, plant protoplasts, plant cell tissue cultures from which field pea plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as embryos, pollen, ovules, flowers, pods, leaves, roots, root tips, anthers, and the like.
The seed of field pea cultivar CDC 0007, the plant produced from the seed, the hybrid field pea plant produced from the crossing of the cultivar with any other field pea plant, hybrid seed, and various parts of the hybrid field pea plant can be utilized for human food, livestock feed, and as a raw material in industry.
Tables
In Table 2, traits and characteristics of field pea cultivar CDC 0007 are compared to several competing varieties of commercial field peas of similar maturity found in the Canada Yield Trials in 2005. In the table below, column 1 shows the variety, column 2 indicates the number of years in the test, column 3 indicates the average percent yield for three southern locations as compared to Alfetta, column 4 indicates the average percent yield from two northern locations as compared to Alfetta, column 5 shows the vine length and column 6 shows the seed weight (g/1000 seeds). The Alfetta variety is the “control” or “standard” the other varieties are compared to. CDC 0001 is also known as CDC Striker.







TABLE 2







PAIRED COMPARISONS

















Seed




% yield for
% yield for
Vine
Weight



Years in
South (3
North (2
length
(g/1000


Variety
Test
locations)
locations)
(cm)
seeds)















CDC 0007
6
117
109
85
230


Alfetta
9
100
100
60
290


CDC Mozart
9
114
107
70
220


Nitouche
9
94
97
75
250


CDC 0001
6
100
108
80
230









DEPOSIT INFORMATION
A deposit of the Alternative Seeds Strategies, Inc., proprietary field pea cultivar designated CDC 0007 disclosed above and recited in the appended claims has been made with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va. 20110. The date of deposit was Jan. 17, 2008. The deposit of 2500 seeds was taken from the same deposit maintained by Alternative Seeds Strategies, Inc., since prior to the filing date of this application. All restrictions upon the deposit have been removed, and the deposit is intended to meet all of the requirements of 37 C.F.R. §1.801-1.809. The ATCC accession number is PTA-8891. The deposit will be maintained in the depository for a period of 30 years, or 5 years after the last request, or for the effective life of the patent, whichever is longer, and will be replaced as necessary during that period.
Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications such as single gene modifications and mutations, somaclonal variants, variant individuals selected from large populations of the plants of the instant cultivar and the like may be practiced within the scope of the invention, as limited only by the scope of the appended claims.

## Claims

1. A seed of field pea cultivar CDC 0007, wherein a representative sample of seed of said cultivar was deposited under ATCC Accession No. PTA-8891.

2. A field pea plant, or a part thereof, produced by growing the seed of claim 1.

3. A tissue culture of regenerable cells produced from the plant of claim 2, wherein said cells of the tissue culture are produced from a plant part selected from the group consisting of leaf, pollen, embryo, cotyledon, hypocotyl, meristematic cell, root, root tip, pistil, anther, flower, stem and pod.

4. A protoplast produced from the plant of claim 2.

5. A protoplast produced from the tissue culture of claim 3.

6. A field pea plant regenerated from the tissue culture of claim 3, wherein the plant has all the morphological and physiological characteristics of cultivar CDC 0007.

7. A method for producing an F1 hybrid field pea seed, wherein the method comprises crossing the plant of claim 2 with a different field pea plant and harvesting the resultant F1 hybrid field pea seed.

8. A hybrid field pea seed produced by the method of claim 7.

9. A hybrid field pea plant, or a part thereof, produced by growing said hybrid seed of claim 8.

10. A method of producing an herbicide resistant field pea plant wherein the method comprises transforming the field pea plant of claim 2 with a transgene that confers resistance to an herbicide selected from the group consisting of imidazolinone, sulfonylurea, glyphosate, glufosinate, L-phosphinothricin, triazine and benzonitrile.

11. An herbicide resistant field pea plant produced by the method of claim 10.

12. A method of producing an insect resistant field pea plant wherein the method comprises transforming the field pea plant of claim 2 with a transgene that confers insect resistance.

13. An insect resistant field pea plant produced by the method of claim 12.

14. The field pea plant of claim 13, wherein the transgene encodes a Bacillus thuringiensis endotoxin.

15. A method of producing a disease resistant field pea plant wherein the method comprises transforming the field pea plant of claim 2 with a transgene that confers disease resistance.

16. A disease resistant field pea plant produced by the method of claim 15.

17. A method of producing a field pea plant with modified fatty acid metabolism, modified carbohydrate metabolism, or decreased phytate content, wherein the method comprises transforming the field pea plant of claim 2 with a transgene encoding a protein selected from the group consisting of phytase, fructosyltransferase, levansucrase, α-amylase, invertase and starch branching enzyme or transforming a plant with an antisense gene of stearyl-ACP desaturase.

18. A field pea plant having modified fatty acid metabolism, modified carbohydrate metabolism or modified phytate content produced by the method of claim 17.

19. A method of introducing a desired trait into field pea cultivar CDC 0007 wherein the method comprises:
(a) crossing a CDC 0007 plant, representative seed having been deposited under ATCC Accession No. PTA-8891, with a plant of another field pea cultivar that comprises a desired trait to produce progeny plants wherein the desired trait is selected from the group consisting of male sterility, herbicide resistance, insect resistance, modified fatty acid metabolism, modified carbohydrate metabolism, or decreased phytate content and resistance to bacterial disease, fungal disease or viral disease;
(b) selecting one or more progeny plants that have the desired trait to produce selected progeny plants;
(c) crossing the selected progeny plants with the CDC 0007 plants to produce backcross progeny plants;
(d) selecting for backcross progeny plants that have the desired trait and the physiological and morphological characteristics of field pea cultivar CDC 0007 listed in Table 1 to produce selected backcross progeny plants; and
(e) repeating steps (c) and (d) three or more times in succession to produce selected fourth or higher backcross progeny plants that comprise the desired trait and all of the physiological and morphological characteristics of field pea cultivar CDC 0007 listed in Table 1.

20. A plant produced by the method of claim 19 wherein the plant has the desired trait and all of the physiological and morphological characteristics of field pea cultivar CDC 0007 listed in Table 1.

21. The plant of claim 20 wherein the desired trait is herbicide resistance and the resistance is conferred to an herbicide selected from the group consisting of imidazolinone, sulfonylurea, glyphosate, glufosinate, L-phosphinothricin, triazine and benzonitrile.

22. The plant of claim 20 wherein the desired trait is insect resistance and the insect resistance is conferred by a transgene encoding a Bacillus thuringiensis endotoxin.

23. The plant of claim 20 wherein the desired trait is modified fatty acid metabolism, modified carbohydrate metabolism, or decreased phytate content, and said desired trait is conferred by a nucleic acid encoding a protein selected from the group consisting of phytase, fructosyltransferase, levansucrase, α-amylase, invertase and starch branching enzyme or transforming a plant with an antisense gene of stearyl-ACP desaturase.