bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Synthetic Varieties of Maize for Yield1
Authors: Hallauer Arnel R. , Eberhart S. A.
Published: July 2010

Nine maize synthetic varieties were crossed in a diallel series and evaluated for yield performance per se and in crosses. The synthetic varieties and crosses were grown at 3 locations in each of 2 years, and, on the basis of the combined analysis over locations and years, the 6 experiments were considered as representative of 6 random enviromnents.

A nonorthogonal partition of the entry sum of squares obtained estimates of average, variety, and specific heterosis. F‐tests indicated that average heterosis was significant at the 1% level in 5 of the 6 experiments and for the combined analysis over experiments. Of the total sum of squares due to heterosis, 73% was attributed to average heterosis. Variety heterosis was significant in the combined analysis, but the proportion of the heterosis sum of squares due to variety heterosis was only 11%. Specific heterosis was nonsignificant.

Estimated and observed heterosis were obtained for each of the synthetic varieties. Average observed heterosis on the basis of constant, mid‐parent, and high parent was 12, 11, and 6%, respectively. Estimated heterosis, obtained as average heterosis (h̄) plus variety heterosis (hj) for each variety, ranged from 6% for C.B. Syn. #1 to 14% for Ind. Syn. A. Average estimated heterosis (h̄) was 11%.

Estimates of synthetic variety effects (vj), obtained for each variety by least squares analysis, included the performance of a variety per se and in variety crosses. The estimates of variety effects ranged from −5.7 for Ind. Syn. A to 5.2 for L.E. Syn., and formed three distinct groups. The relatively large, positive vj group included C.B. Syn. #3, S.S. Syn., and L.E. Syn. Pa. Int. Syn. had essentially zero variety effects. C.B. Syn. #1 and #2 and Ind. Syn. A. and B had relatively large, negative effects.

The correlation between the predicted (Ŷj = μv + vj) and observed yield performance of the nine synthetic varieties was significant (r = .92**), as was the correlation between predicted [Cjj = μv + 1/2 (vj + vj) + h̄] and observed variety cross performance (r = .74**).
Heterosis and Inbreeding Depression in Diploid and Tetraploid Cottons1
Authors: Young E. F. , Murray Jay C.
Published: July 2010

Heterosis was found in both the diploid and tetraploid species of cotton. Of the traits studied, heterosis was most pronounced in yield in both species. The degrees of heterosis shown by G. arboreum were similar to those reported for self‐pollinated diploid species. The G. hirsutum hybrid combinations exhibited less heterosis than the G. arboreum hybrids and were less sensitive to inbreeding. These results indicate that the tetraploid species may carry an accumulation of favorable dominant growth genes in duplicate, a factor which results in a type of built‐in heterosis.
A Serological Study of Medicago sativa L. Varieties1
Authors: Esposito V. M. , Ulrich V. , Burrell R. G.
Published: July 2010

Certified seed of Medicago sativa L. ‘Atlantic,’ ‘Cayuga,’ ‘Culver,’ ‘DuPuits,’ ‘Haymor,’ ‘Narragansett,’ ‘Orchies,’ ‘Vernal,’ and ‘Warrior’ were utilized in this study to investigate the possibility of employing serological methods for the identification of M. sativa varieties.

Specific serological tests appear to be sufficiently definite for the identification of seed protein phenotypes. The results indicate that it is possible to identify nine varieties and to distinguish one from another. At this time, the basis of this intervarietal variation cannot be entirely ascribed to either genetic or environmental components, since both have been shown to influence protein content in other plants and animals; thus, a combination of genetic and environmental components may also be responsible for the diversifications displayed by Medicago sativa varieties. This method of seed identification, if proven to hold over the entire spectra of varietal seed, will offer a relatively fast and inexpensive means for identifying seed. The extreme economy of materials and time is of real advantage in any analysis, but especially so in this type of testing for varietal purity.
Inheritance and Significance of Dwarfism in an Indica Rice Variety
Authors: Aquino R. C. , Jennings Peter R.
Published: July 2010

Analysis of F1, reciprocal backcross, F2, and F3, data showed that dwarfism in the high‐yielding, nitrogen responsive Taiwanese indica variety, ‘Taichung Native 1,’ is controlled primarily by a single recessive gene. Minor gene action, confirmed from F3, lines, allows flexibility in selecting a range of short‐statured types. Correlation studies with maturity and tiller number and field observation with several traits of primary interest have shown no association with height and, hence, no barrier to free recombination. The dwarf gene shows no association with floret sterility, incomplete panicle exsertion, or abnormal plant and grain development in the parent dwarf or its progenies. Large numbers of fixed lines, carrying the dwarf gene in distinct genetic backgrounds, have been isolated and tested. All results indicate a major advance in the development of short‐statured, lodging resistant, nitrogen responsive, and productive tropical varieties.
Growth Rate and Yield in Sericea Lespedeza in Relation to Seed Size and Outcrossing1
Authors: Cope Will A.
Published: July 2010

Sericea lespedeza seed were obtained from open‐pollinated chasmogamous flowers and from self‐fertilized cleistogamous flowers from both an outcrossed and a caged plant in each of 10 inbred lines. Chasmogamous seed are approximately 20% heavier than cleistogamous seed; thus, the four progenies in each line allowed comparison of both outcrossing and seed size effects. In a greenhouse test seed size superiority averaged nearly 8% for measurements over a 4‐month period; in the field test initial values were similar but disappeared after 2 months. A superiority for outcrossing was apparent in each test only after several weeks, reaching a maximum of 8.5% over the maternal parents at the end of the first growing season in the field. The small increase from outcrossing possibly reflects both a low level of heterosis and a low percent cross‐pollination. Within the 10 lines seed size was significantly correlated with seedling performance; thus selection for seed size involves genetic factors for growth rate other than seed size alone. Both seed size and heterosis require attention of the plant breeder; however, the levels of effects reported here place definite restrictions on progress to be expected and breeding systems to be used effectively.
Red‐root in Alfalfa: Inheritance and Relationship with Flower Color1
Authors: Clement William M. , Stanford E. H.
Published: July 2010

Inheritance of a character conditioning anthocyanin pigmentation in the roots of alfalfa was determined to be governed by a single dominant gene, Rd, inherited in a tetrasomic manner. The c gene controlling white‐flowers was epistatic to the Rd gene, red‐root being expressed only in plants with colored flowers. The c locus appeared to be a basic color factor for anthocyanin production in all plant parts. The reason for a negative correlation of intensity of flower and root color observed in one family was not evident. Although most of the data were consistent with the hypothesis proposed, the digenic segregations for the Rd and c genes did not fit expected ratios. Linkage and viability problems were among the likely reasons.
Preliminary Groupings of Plant Introductions of Alfalfa (Medicago sativa, L.) for Heterosis Studies1
Authors: Dudley John W. , Davis R. L.
Published: July 2010

In preparation for a study of between and within group crosses as sources of heterotic combinations we classified 144 plant introductions into eight groups. Three replications of five plant plots of each introduction were grown from original seed in North Carolina and Indiana and evaluated for a number of characters. Based on origin, winter‐hardiness, leafhopper yellowing score, growth index in North Carolina and growth index in Indiana we classified 7 introductions of M. sativa var. gaetula as gaetula; 5 introductions as gaetula‐like; 50 as Chilean; 20 as Chilean‐like; 90 as Flemish; 19 as Afghan; 9 as Afghan‐like; and 14 as non‐hardy. When the groups with the suffix “‐like” were combined with groups having the same name, five major groups were formed. Countries considered to be in the center of origin of alfalfa contributed entries to all but the Chilean major groups.

Ways of using the proposed groups for increased efficiency in the search for heterotic combinations and for more precise preliminary classification of new plant introductions are proposed.
Vernstein — a Triticum aestivum Derivative with Vernal‐Emmer‐type Stem Rust Resistance1
Authors: Luig N. H. , Watson I. A.
Published: July 2010

A factor for resistance to wheat stem rust present in the T. durum variety ‘C.I. 7778‘ and transferred to a T. aestivum genotype resembles the gene Srd 1,v of ‘Vernal Emmet.’ In crosses with the susceptible variety ‘W 2691’ this factor is transmitted differentially. Seed of tile derived hexaploid Vernstein is available on request. The nature of other genes derived from C.I. 7778 is also discussed
Heterosis in Oats1
Authors: Petr F. C. , Frey K. J.
Published: July 2010

Several attributes were studied in the F1 and F2 generations of oat crosses grown in space‐planted nurseries in 1955. The F1's of 15 oat crosses and their parents were sown in a randomized complete‐block design with 3 replicates. The plots, spaced 30 cm apart, each contained 5 competitive plants (sown 30 cm apart) upon which measurements were taken for heading date, number of panicles per plant, number of spikelets per primary panicle, plant height and grain yield. In 1957, the F2 and parent plants were spaced 10 cm apart and measured for the same attributes as the F1's.

The grain yields of each F1 exceeded the higher yielding parent. Grain yields in the F1 ranged from 101 to 130% of the higher parent with a mean for all crosses of 112%. The parent, Victory, produced consistently low yielding crosses. The yields of some crosses in the F2 exceeded the higher yielding parent and the mean F2 yields, relative to the higher yielding parent, was 99%. For one cross, the relative yield of the F2 was 120% of the higher parent.

Positive heterosis was expressed for number of panicles per plant, and for each cross the heading date of the F1 was earlier than the midparent. Except in a few crosses, plant height and number of spikelets per panicle in the F1's and F2's closely approximated the midparents.

The correlations of midparental values with Ft and F2 cross means for number of spikelets per panicle, plant height and heading date were all highly significant and above 0.89. For yield, similar correlations were 0.60.
Linkage Studies of Various Barley Mutations (Hordeum Species)1
Authors: Robertson D. W.
Published: July 2010

Linkages of two genes in barley — Albino 2 a2 and rattail rt — have been established on Chromosome 2. The order of genes on the chromosome are: rt, or, a2, f, e, and v. An additional gene has been added to Chromosome 3. The order of genes on this chromosome are: ac, xc, wst, an, and xs.
Thermal Stability of Malic Dehydrogenase from Heat‐Hardened Phaseolus acutifolius ‘Tepary Buff’1
Authors: Kinbacher E. J. , Sullivan Charles Y. , Knull H. R.
Published: July 2010

Malic dehydrogenase was extracted from high temperature hardened and unhardened leaves of 4‐ to 5‐weekold, greenhouse grown, 'Tepary Buff beans. Purified fractions of malic dehydrogenase were exposed to temperatures that ranged from 30 to 62 C for 15 minutes. The specific activity of the enzyme was markedly reduced by temperatures above 50 C. Malic dehydrogenase extracted from hardened plants was significantly more thermostable than the extracts from unhardened tissue. The extracts from hardened tissue also exhibited a significantly higher specific activity over a wider pH range than the extracts from unhardened tissue.

The results from heat tolerance tests with intact leaf discs correlated well with the reduction in activity of the extracted malic dehydrogenase. These data indicate that enzyme denaturation is an important factor in heat tolerance. One way that high temperature hardening may increase the heat tolerance of higher plants is by increasing the thermal stability of enzymes.
Seedling Growth of a Hypogeal Legume, Vicia dasycarpa, in Relation to Seed Weight1
Authors: Williams William A.
Published: July 2010

Increasing seed weight resulted in increased seedling dry weight and increased leaf area but did not affect the relative growth rate of Vicia dasycarpa. Varying the depth of planting did not significantly affect seedling dry weight or leaf area during time intervals measured from emergence. The inference was drawn that cotyledonary reserves do not have a major influence on the size of the photosynthetic organs of this hypogeal species.

Since these results are similar to those reported by others for epigeal legumes, it is suggested that the positioning of the cotyledons in either the aerial or the subterranean enviroment has no marked effect on the growth in dry weight or leaf area of forage legumes.
Estimates of Genetic and Environmental Variability in Barley1
Authors: Rasmusson D. C. , Glass R. L.
Published: July 2010

Two populations of F3 derived lines of barley were studied in the F5, F6, and F7 generations. Variance components and heritability were estimated and genetic advance predicted for each of seven traits. The genotype ✕ environment interaction components of variance were smaller than the genotype and plot error components for all traits, except percent nitrogen in one population. Estimates of the second order interaction, σ2gly, were generally larger than those of the first order interactions, σ2gl, and σ3gy Heritability estimates were highest for heading date and diastatic power, intermediate for kernel plumpness, height, and extract, and lowest for yield, for percent nitrogen, heritability was relatively high in population 1 and low in population 2.

Under the conditions of this study, a single trial with 3 replicates gave sufficient information for each of the seven traits to provide favorable odds of including the elite lines if the top 25% were selected.

Data from triplicate determinations of percent nitrogen, percent extract, and diastatic power indicated that replication in our laboratory testing is unnecessary.
Development of Single‐Cross Hybrids from Two‐Eared Maize Populations1
Authors: Hallauer Arnel R.
Published: July 2010

A procedure for the development of single‐cross hybrids from two‐eared maize populations was outlined. Selections are made among individual plant crosses in each generation of inbreeding. Selection among individual plant genotypes is continued until the plants are relatively homozygous, at which time one should have a group of selected single‐cross hybrids that have been tested at each level of inbreeding. The procedure is designed to maximize selection for nonadditive genetic effects.

Two generations of individual plant selection for yield have been completed. A mild selection intensity (approximately 36%) was used in each generation. Relative to six common hybrid checks, selection was effective in the first generation.
Reaction of Permutations of Maize Double Crosses to Leaf Feeding of European Corn Borers1
Authors: Scott Gene E. , Guthrie W. D.
Published: July 2010

We tested the 3 permutations of 12 double‐cross hybrids plus all possible single crosses among 8 inbred lines for their reaction to first‐brood infestation by European corn borers. Double crosses with three or more resistant lines in their pedigree had a high level of resistance. Double crosses containing two highly resistant lines had an acceptable level of resistance. The differences which occurred in double‐cross permutations were primarily in hybrids composed of two resistant and two susceptible inbreds. However, the differences among permutations were small as compared to the total difference between resistant and susceptible plants. Differences between observed and predicted values of some permutations indicated that some type(s) of epistatic gene action was important in the expression of corn borer resistance.
Further Studies on the Inheritance of Ovule Number in Pisum1
Authors: Marx G. A. , Mishanec W.
Published: July 2010

Ovule number in Pisum was shown to be controlled by a simple, additive genetic system, with perhaps as few as three loci governing the entire range. An association was demonstrated between the Bt locus (conditioning the shape of the pod apex) and the number of ovules per ovary. The nature of the association, linkage or pleiotropy, remains unsettled.
Maternal Line Selection for Persistence in Red Clover, Trifolium pratense L.1
Authors: Mokhtarzadeh A. , Leffel R. C. , Beyer E. H.
Published: July 2010

Effectiveness of maternal line and phenotypic selection for persistence among and within locally adapted strains of red clover and concurrent shifts in population characteristics were studied in two field studies at Fairland, Md. Original parental strains were compared with breeding materials derived by breeding procedures in spaced and simulated broadcast plantings. Maternal line selection and synthesis of varieties from clones selected phenotypically within the third cycle of maternal line selection were both effective in improving persistence of red clover; the latter method appeared to be the most efficient one. Improvement in persistence was accompanied by decreased forage yields in first year stands and increased forage yields in second year stands, decreased flowering in first year and delayed flowering date in second year, and a more rosette type of plant growth in the fall.
Bivalents in Metaphase I of Haploid Linum africanum L.1
Authors: Yermanos D. M. , Gill K. S.
Published: July 2010

Bivalents with chiasmate at metaphase I in pollen mother cells of haploid Linum africanurn L. (n=15) indicate that it may have evolved through autopolyploidy.
Light and Carbon Assimilation by Plant Communities1
Authors: Hesketh J. , Baker D.
Published: July 2010

In general, the shape of the response curves of leaf CO2‐assimilation rate plotted against light intensity is predictable from the CO2‐assimilation rate in intense light. Of four factors limiting photosynthesis in intense light, the one causing differences between tropical grasses and other species has received much attention recently. Two other factors, associated with diffusion of CO2, have been well defined; little is known about a fourth factor. Four hypotheses are discussed. The photosynthetic rate of a crop stand may be defined as the product of the amount of light intercepted and the efficiency of the intercepting tissue. Interception depends on solar angle and stand geometry. Efficiency is often constant over considerable periods of time (several examples are discussed). This indicates, in species whose leaves exhibit hyperbolic light response curves, either (a) that there are other important light‐intercepting tissues, e.g., stems and fruit, with different photosynthetic light response curves, or (b) that the manner in which light is received by the leaves changes. In the second case, it is implied that leaves move.
Electrophoretic Differences in Seed Proteins among Varieties of Soybean, Glycine max (L.) Merrill1
Authors: Larsen Arnold L.
Published: July 2010

Seed proteins of 61 soybean varieties were analyzed by disc electrophoresis. The stained proteins in the polyacrylamide gels revealed two components that separated the varieties into two major groups. Component “A” was present in 13 varieties, and component “B” was present in 48 varieties. In no instance were A and B observed in a single variety. Repeated tests with seed from various environments produced no exceptions to the varietal grouping with respect to these two proteins.
Relationship of Winter Habit and Malting Quality in Spring ✕ Winter Barley Crosses1
Authors: Smith D. H.
Published: July 2010

Twelve crosses of winter ✕ spring barley were made using hardy winter varieties and high‐malting‐quality spring lines as parents. F3 rows of the progenies of these crosses were classified as spring, winter, and intermediate, based on heading date. Bulks were made within crosses of each growth habit class and malted in micromalting equipment. Quality evaluation of the bulk malts show that malt quality is independent of growth habit. Winter growth habit proved independent of any association detrimental to malting quality.
Heritability of Sr‐89 and Ca‐45 Accumulation in Barley Seedlings1
Authors: Fick Gerhardt N. , Rasmusson Donald C.
Published: July 2010

Heritability of Sr‐89 and Ca‐45 accumulation in seedling plants was studied in two crosses of barley. Seedling plants of parent, F1, F2, F3, and F4 generations were grown in nutrient solution containing Sr‐89 and Ca‐45. Broad sense heritability estimates for Sr‐89 and Ca‐45 accumulation in the F2 generation of the two crosses ranged from 36% to 58%. Estimates of heritability in the F3 generation as obtained from the correlation of F3 with F4, lines were 55% and 50% for Sr‐89 accumulation and 49% and 41% for Ca‐45. These estimates are sufficiently large to indicate that selection for high or low Sr‐89 and Ca‐45 accumulation would be effective on a single plant basis in F2 and on the line basis in F3. Actual gains in FF4 from hypothetical selection in FF3 were substantial and similar to those predicted, particularly when selection was for low Sr‐89 and low Ca‐45 accumulation.

Differences among lines in the ratio of Sr‐89/Ca‐45 were not heritable in the F3 generation. Accumulation of Sr‐89 and Ca‐45 was highly correlated in the F3 and F4 generations. Thus, the data indicate a close relationship between Sr‐89 and Ca‐45 accumulation in the populations studied.
Phytotoxicity of Herbicides to Spanish Peanuts (Arachis hypogaea L.) as Influenced by Planting Depth and Simulated Rainfall1
Authors: Santelmann P. W. , Matlock R. S. , Six Lee
Published: July 2010

The phytotoxicity of five herbicides to spanish peanuts was evaluated under conditions of two planting depths (2 and 4 on) and two sprinkler irrigation regimes. In one regime 5 cm of water were applied immediately after planting and treating and the other regime consisted of natural rainfall. No herbicide treatment consistently reduced peanut yields below the untreated check over a 3‐year period, regardless of planting depth or moisture regimes. Peanut grades were also not affected. Weed control was good with all treatments.
Use of Area‐Weight Relationship to Estimate Leaf Area in Alfalfa (Medicago sativa L. Cultivar ‘Moapa’)1
Authors: Robison Cayland D. , Massengale M. A.
Published: July 2010

The relationship of leaf area to leaf weight was studied in Moapa alfalfa to determine if leaf weight could be used as an estimation of leaf area. Four harvest management regimes and three growth periods were utilized. Leaflets were removed, weighed, verifaxed for measuring with a planimeter, and the oven‐dry weight determined. The seasonal change in total leaf area and in size of individual leaves did not appreciably influence the leaf area‐leaf weight relationship. Data show that leaf weight can be used to determine leaf area in Moapa alfalfa.
Vegetative Development and Organic Reserves of Tall Fescue Under Conditions of Accumulated Growth1
Authors: Lopez Restituto R. , Matches Arthur G. , Baldridge J. D.
Published: July 2010

We evaluated tiller and bud development and storage of organic reserves by ‘Kentucky 31’ tall fescue under accumulated growth conditions. Number of tillers increased from June to July and remained fairly constant thereafter. Number of buds increased progressively from June to September before leveling off. Buds were located predominantly on the stem bases, with fewer buds on the nodes of connecting rhizomes. Most buds remained short or dormant from June 23 to November 12. Apparently, summer growth under accumulated growth conditions arose largely from tillers that were present in June; only a few buds elongated to form new tillers. Organic reserves increased 174% between August and November, followed by a 30% decline between January and February.
Field Evaluation of Glanded and Glandless Cotton (Gossypium hirsutum L.) Lines for Boll Weevil (Anthonomus grandis Boh.) Susceptibility1
Authors: Jenkins Johnie N. , Maxwell Fowden G. , Parrott W. L.
Published: July 2010

The boll weevil is the major cotton insect in the rain grown cotton belt. We investigated glandless cottons to determine if they were more susceptible to the boll weevil than the currently grown glanded varieties. Two years' results from large field plots with two pairs of glanded glandless cottons indicated that the glandless genes gl2 and gl3 did not cause greater susceptibility in the Acala 4‐42‐77 and Rex Smoothleaf lines. Thirteen pairs of glanded‐glandless lines were compared in small field plots. In each of the 13 comparisons no significant differences were found. Antibiosis tests showed slightly larger weevils on some glandless lines. These data suggest that the glandless character should not create any increased boll weevil susceptibility, especially with careful selection of genetic background.
Jointing and Survival of Rye Plants and Clones Through Successive Seasons1
Authors: Wells D. G. , Albrechtsen R. S. , Yeh Yung‐Yen
Published: July 2010

Clones can be used in rye improvement if portions are preserved vegeatively long enough for evaluation and use in breeding. Plants and clones of ‘Von Lochow’ and ‘Caribou’ rye were observed in the greenhouse under 8‐hour, natural, and 24‐hour days. Continuous light prevented jointing of both varieties. Natural daylength prevented jointing of Von Lochow. Survival of over‐summering clones was best in full shade and natural daylength, poorest in full shade with continuous artificial illumination, and fair in partial shade with natural daylength. Some segments of all clones over‐wintered successfully in the field. Jointed tillers winterkilled but had no apparent effect on adjacent vegetative tillers in the same clonal segment.
Variegated Mutants in Cotton, Gossypium hirsutum L.1
Authors: Kohel R. J.
Published: July 2010

Variegated plants were observed as spontaneous mutations in the cotton nurseries, as an induced mutation in a line isolated from a seed‐irradiated population, and as reoccurring mutations in a genetic marker line. Genetic analysis of this mutant‐condition indicated that it is maternally inherited. Observations of the segregation patterns and development of this mutant led to the conclusion that mutant plants result from plastid mutations. The influence of the environment on the expression of this mutant phenotype and the possibility of nuclear control of the plastid mutation were discussed.
A Diallel Analysis of Several Fiber Property Traits in Upland Cotton (Gossypium hirsutum L.)1
Authors: Verhalen Laval M. , Murray Jay C.
Published: July 2010

Diallel analyses of upper 2.5% span length, micronaire, ⅛″ gauge stele‐meter strength, and 0″ gauge stelometer strength were conducted on 10 selected varieties of upland cotton and the 45 possible F1 crosses among them using the procedure of Jinks and Hayman. A partial failure of the basic assumptions of the analysis was noted for length and micronaire. The assumptions were valid for ⅛″ gauge stelometer and O″ gauge stelometer.
Components of Height Inheritance of the Semidwarf Straw Character in Wheat Triticum aestivum L.1
Authors: Powell Jerrel B. , Schlehuber A. M.
Published: July 2010

Internode patterns of both the semidwarf and tall parents, used in a cross to study the inheritance of plant stature, revealed that: I) Average internode lengths were progressively longer from the base of the culm to the spike, and 2) The peduncle contributed approximately one‐half the total height of the tall parent and about one‐third the total height of the semidwarf parent in field plantings. The analysis of means for the three components, head length, peduncle length, and culm length (less peduncle), showed that head length in the segregating tall progeny added negative genetic components to total plant height. Gene effects tended to cumulate additively for peduncle length and culm length (less peduncle). Partitioning of populations for the two major components of plant height and total plant height pointed to one major nondominant factor accounting for most of the genetic variation differentiating the semidwarf and normal‐statured wheat.
Frequencies of Induced Mutations In M2 and M3 Generations in Bread Wheat
Authors: Goud J. V.
Published: July 2010

The mutation frequency was high in the M2 generation as compared to the M3 generation. The progenies which segregated to mutation in M2 contained a higher mutation frequency in M2 than those which were normal in the M2 generation.
Digestibility, Morphology, and Chemical Composition of Pearl Millet1
Authors: Hart Richard H.
Published: July 2010

Dry matter digestibility (DMD) of stems and whole plants of eight pearl millet genotypes was positively and significantly correlated with leafiness from about the boot stage to maturity, but not before. DMD of leaves was not significantly correlated with leafiness at any stage. Within genotypes, DMD of leaves, stems, and whole plants was positively correlated with leafiness and negatively correlated with age; nearly all correlations were significant, but the latter were generally larger in absolute value. Lignin content was an excellent predictor of DMD; correlation coefficients were −.91 for leaves and −.88 for stems. DMD of leaves, but not of stems, was significantly correlated with crude protein and crude fiber content, but less closely than with lignin content.
Phenotypic Stability in Soybean Populations1
Authors: Smith R. R. , Byth D. E. , Caldwell B. E. , Weber C. R.
Published: July 2010

Phenotypic stability of various soybean (Glycine max (L.) Merrill) genotypes to a series of environments investigated by computing, for each genotype, a linear regression of yield onto the mean of all genotypes for each environment. Genotypes expressing above average stability were influenced less by changing environmental conditions. Low deviations from regression tended to be associated with regression coefficients below 1.0.

A positive association was observed between mean homogeneous daughter line and heterogeneous maternal line performance. However, heterogeneous, homozygous lines responded less radically to environmental changes than corresponding homogeneous, homozygous lines.
Preliminary Investigation on the Reproductive and Morphological Behavior of Several Selections of Colonial Bentgrass, Agrostis tenuis, Sibth.1
Authors: Dudeck A. E. , Duich J. M.
Published: July 2010

The purpose of this investigation was to determine if a systematic program of inbreeding and selection is a practical method of breeding colonial bentgrass, Agrostis tenuis Sibth. Inbreeding effects were investigated in 95 parental selections having open‐pollinated origins in Oregon and in 277 first inbred generation progenies. Self‐ and open‐pollinated seed‐setting, self‐fertility, pollen quality and the creeping habit of growth were studied.

The results of this experiment indicate that it is possible to obtain highly vigorous second generation inbred plants. Inbreeding and selection within inbred lines is a practical method for breeding colonial bentgrass. Most plants were observed to spread by means of determinate stolons which originated as determinate rhizomes.
Inbreeding in Two Populations of Zea mays L.1
Authors: Sing C. F. , Moll R. H. , Hanson W. D.
Published: July 2010

Inbreeding effects on five characteristics of two Zea mays varieties were estimated. Seven inbred subpopulations, ranging from F = O to 9/16, of each variety were obtained by using double‐double (8‐line) pedigrees. Environmental error and genotype‐by‐environment interaction components of variance were not significantly affected by the level of inbreeding. The regression of performance on expected inbreeding was linear for yield, number of days to tassel, ear height, and plant height. If epistatic effects are contributing to the variability in these two populations they must be of the type which lead to a linear relationship between average performance and inbreeding. Inbred progenies derived from sets of inbred lines were analyzed separately. Variability in response to inbreeding among such sets of genetic material was detected.
Morphology and Chlorophyll Content of Shade and Sun Leaves of Two Legumes1
Authors: Cooper Clee S. , Qualls Mickey
Published: July 2010

The increase in the ratio of leaf area to leaf weight which occurs with shading of legumes was associated with changes in leaf morphology and chlorophyll content. Alfalfa and birdsfoot trefoil had more stomata per cm2 of leaf when grown in the sun than in the shade. Sun leaves of both species were thicker than shade leaves. Number of palisade and mesophyll cells and cell volume appeared greatest in sun leaves, and the palisade layer was more clearly differentiated. Shaded leaves contained more chlorophyll per unit of leaf weight but less per unit of leaf area than sun leaves.
Chromosomal Association with Gliadin Proteins in the Wheat Variety ‘Cheyenne’
Authors: Eastin Jerry D. , Morris Rosalind , Schmidt J. W. , Mattern P. J. , Johnson V. A.
Published: July 2010

Gliadin protein patterns from ‘Cheyenne’ chromosome substitution lines in ‘Chinese Spring’ were examined for possible association with desirable dough‐handling and bread‐baking properties. In a previous report, chromosomes 4B, 7B, and 5D have been associated with desirable dough‐handling properties. However, in the present study, glaidln protein patterns of chromosomes 4B, 7B and 5D were not similar. Likewise, chromosomes 1B, 4B, and 7B which were previously noted for their association with desirable loaf characteristics did not share distinctive protein patterns. Marked differences among gliadin patterns for Cheyenne chromosomes both between and within the three genomes of wheat were apparent. Their meaning in terms of flour quality factors is unclear.
Effect of Nitrogen on Accumulation of Ketone Bodies in Orchardgrass1
Authors: McKee W. H.
Published: July 2010

Two experiments were conducted in a growth chamber to study effects of carbohydrate reserves, nitrogen fertilization, and carbohydrate intermediates on accumulation of ketone bodies and carbohydrate depletion in orchardgrass stubble.

Acetate as a ketone body precursor caused a marked increase in ketone body levels, especially with low as compared with high carbohydrate reserves. When glucose was added a further drop in the ketone body level occurred. Ketone body levels varied with nitrogen and carbohydrate reserves in the stubble in a second experiment. There was an inverse relationship between reducing sugars and the amount of ketone bodies extracted from the stubble for low carbohydrate reserve treatments. Ketone body contents did not vary with treatments for plants high in carbohydrate reserves.
Combining Ability of Transgressive Segregates in Sugarbeets1
Authors: Hecker R. J.
Published: July 2010

Transgressive segregation in an F2 generation for increased root size in sugarbeets (Beta vulgaris L,) indicates the presence of genes with additive effects which condition this character. These genes are probably not unique to the inbred parents of this F2. Seven interpollinated transgressive segregants produced heavier roots than an interpollinated random sample from the F2. However, the combining ability of these seven transgressive segregants was not different from that of an F2 random sample, or a less intensely selected group of 64 plants. This study indicates that individuals superior because of additive genes may have no better combining ability than a random sample from their parent population.
Effects of Genetic Heterogeneity Within Two Soybean Populations I. Variability Within Environments and Stability Across Environments1
Authors: Byth D. E. , Weber C. R.
Published: July 2010

Two random and unselected populations of genetically heterogeneous F2‐derived, and homogeneouls F2‐derived soybean lines were evaluated for nine agronomic and chemical characters in three environments in F6‐F7 generations. Average performance of the heterogeneous and homogeneous lines was equal across environments for all traits except maturity and plant height, which were possibly overestimated in heterogeneous populations.

F2‐derived lines revealed greater phenotypic stability across environments than F2derived lines. This was related to the degree of genetic heterogeneity within F2‐derived lines, while genetic uniformity within F5‐derived lines resulted in large genotype ✕ environment interactions in all characters. Also, homeostatic effects due to heterogeneity within a line were shown by lower variance among heterogeneous F2‐derived lines than for homogeneous F5‐derived lines for all characters in all environments.

Implications in selection procedures of homeostatic effects within and across environments resulting from heterogeneity within relatively homozygous soybean lines were discussed.
Further Evidence on Testcross Versus Line Performance in Maize1
Authors: Lonnquist John H.
Published: July 2010

A total of 169 S1 lines out of KrugIII synthetic were evaluated as (1) lines per se, (2) testcrosses to an unrelated tester, and (3) testcrosses to the parental population. The three highest‐ and three lowest‐yielding from each of the three evaluation series were used to study their intercross behaviour. The 18 lines were intercrossed. Composites of HH, HL, and LL crosses within each set of 6 lines and crosses between sets (H1H1, H1L1, L1H1 and L1L1) provided the material for test evaluation in 1965‐66. In each evluation series the superior lines [>(p̄ + σp)] had been selected to form new cycle populations. These populations (Cycle IV) together with the parental, KIII synthetic, were included in the performance trials.

The LL, HL, and HH groups from line per se selections exhibited a linear trend for yield. Selection on the basis of an unrelated tester resulted in the HL group ≥ the HH group. Intercrosses of lines selected on the basis of the parental population as the tester exhibited a linear yield trend but with evidence of partial dominance for high yield. Highest yields resulted from intercrosses of lines selected on the basis of performance in testcrosses with the parental population.

With respect to the newly derived populations, that based upon selection from testcrosses with the parental population (KIV‐3) exhibited a 15% increase in yield relative to KIII synthetic. Line per se selection resulted in a 4% gain in yield, whereas no gain resulted from selection based upon evaluation in testcrosses with the unrelated tester parent.
Influence of Defoliation and Nitrogen on the Development and the Fructan Composition of the Vegetative Reproductive System of Timothy (Phleum pratense, L.)1
Authors: Sheard R. W.
Published: July 2010

A sequence of development of the vegetative reproductive system of timothy consisting of primary and secondary haplocorms and tertiary shoots is proposed. Initiation of spring growth was from tertiary shoots and independent of the primary and secondary haplocorms. Nitrogen fertilization at 280 kg N/ha decreased the dry weight and fructan in primary haplocorms but increased the dry weight and fructan in the secondary haplocorms, particularly during the initial formative period. Nitrogen increased the dry weight but lowered the fructan concentration in the tertiary shoot. Survival and spring growth were not restricted where the fructan in the tertiary shoot was reduced by two‐thirds to a level of 5% over the winter dormancy period.
Total Available Carbohydrates in Roots of Sainfoin (Onobrychis viciaefolia Scop.) and Alfalfa (Medicago sativa L.) when Grown Under Several Management Regimes1
Authors: Cooper C. S. , Watson C. A.
Published: July 2010

Total available carbohydrate (TAC) in roots of alfalfa (Medicogo sotiva L.) and sainfoin (Onobrychis viciaefolia Scop.) was measured throughout the growing season when plants were left uncut or cut two, three, and four times. TAC in roots of uncut alfalfa declined with the advent of spring growth, increased to a peak at 1/10 bloom, declined again with new growth, and then increased to a stable level in late summer and fall. In contrast, TAC in roots of uncut sainfoin decreased until flowering and then increased until seed had matured. New basal shoot growth did not occur during this period. At seed maturity, new basal shoot growth was accompanied by a slight decrease in root TAC followed by an increase and stabilization of TACle vel in early fall.

Whenc cut two, three, or four times, TACin roots of alfalfa followed a typical pattern of accumulation and utilization. TAC in roots of sainfoin showed less cyclic fluctuation with cutting and remained at low levels until late summer and early fall. It was hypothesized that following the use of TAC reserves in early spring, growth of sainfoin depends primarily upon carbohydrates synthesized in existing leaf area.
Hybrid Vigor in a Seven‐Parent Diallel Cross in Common Winter Wheat (Triticum aestivum L.)1
Authors: Fonseca Santiago , Patterson Fred L.
Published: July 2010

Levels of hybrid vigor for earliness, height, three components of yield, and grain yield were examined in the F1 and F2 generations of a diallel cross of seven varieties selected from hard red, soft white, and soft red winter wheats. Entries planted in hills showed little interaction with seeding rates of 3 to 15 plants per 930 cm2 (1 ft2), but the degree of hybrid vigor tended to be greater for hill seeding than for normal seeding.
Quality Tests on Six Substitution Lines Involving ‘Cheyenne’ Wheat Chromosomes1
Authors: Morris Rosalind , Schmidt J. W. , Mattern P. J. , Johnson V. A.
Published: July 2010

Mixing curves and baking tests were obtained for four substitution lines involving chromosomes 2A (XIII), 2B (II), 2D, and 7A of the hard red winter wheat variety Triticum aestivum L. em. Thell (aestivum group) ‘Cheyenne’ after four backcrosses to the ‘Chinese Spring’ variety. At the time of a previous report these lines had not had sufficient backcrosses. Tests also were made for the parental varieties, and for Cheyenne substitution lines 4B, which resembled Cheyenne, and 3D, which resembled Chinese Spring, in previous tests. Lines 2A, 2B, 2D and 7A were similar to Chinese Spring in mixing curve and baking characteristics, indicating that these Cheyenne chromosomes do not demonstrate any genetic control over the Cheyenne flour properties, at least when isolated from the rest of the complement.
Technique for Space Planting Wet Barley Seeds in the Field1
Authors: Myhill R. R. , Nilan R. A.
Published: July 2010

A technique involving wooden bars for space planting barley (Hordeum vulgare) seeds in the field is described. The bars are drilled with holes 1″ apart to contain the seeds and are fitted into a specially constructed wooden box for transporting. A special furrow‐making tool which can be attached to a tractor is also described. This technique has been used successfully for planting mutagen‐treated barley seeds, even when they are wet.
Polyethylene versus Glassine Shoot Bags in Pollination of Corn (Zea mays L.)1
Authors: Tsangarakis C. Z. , Fleming A. A.
Published: July 2010

Individual plant data from 300 single‐cross plants consisting of 10 replications were used. Of the eight characteristics studied, the glassine bags were significantly better than the polyethylene bags with respect to the following: 1) moisture inside the bag one day before pollination; 2) moisture inside the bag on day of pollination; 3) number of kernels per ear; and 4) distribution of kernels per ear.

A significantly better rating was obtained for condition of bags on the day of pollination than on one day before pollination within the polyethylene treatment. The better rating is attributed to silk growth during the interval.

The simple correlation value of ‐.45** indicated that an increase in the amount of moistiire inside the shoot bag caused a decrease in number of Kernels. Ears under glassine bags produced 14.40 kernels more per ear than those under polyethylene. Moisture inside the bag and length of silks were negatively correlated (r = ‐.23**). An r value of +.27** was obtained between length of silks and number of kernels per ear. Bags standing upright on the shoot had less moisture (r = ‐‐.21*).
Fatty Acid Composition of the Oil of Developing Seeds of Different Varieties of Safflower1
Authors: Hill A. B. , Knowles P. F.
Published: July 2010

The seed weight of safflower (Carthamus tinctorius L.) increased most rapidly during the first 15 days after flowering, and reached maximum dry weight in about 28 days. On a weight basis, oil content increased 5‐ to 10‐fold in the period 10 to 15 days after flowering. Expression of control by the genes governing differences in fatty acid composition began about l0 days after flowering.
Canopy Architecture at Various Population Densities and the Growth and Grain Yield of Corn1
Authors: Williams W. A. , Loomis R. S. , Duncan W. G. , Dovrat A. , Nunez F. A.
Published: July 2010

Parameters of canopy architecture were related to light interception and productivity using data from a field experiment with corn grown at population densities from 17,500 to 125,000 plants per hectare. With nutrients and soil moisture nonlimiting, the amount of solar radiation intercepted by the foliage canopy was a major determinant of crop growth during the vegetative stage. Leaf arrangements with a preponderance of erect leaves, occurring just before the tassels emerged, allowed the deepest penetration of light into the foliage canopy and gave the highest crop growth rates. Computer simulation of photosynthetic production using the measured foliage display characteristics closely approximated measured rates of growth before anthesis. The yield of grain correlated well with crop growth rates up to an optimum population density, but then became negatively associated with density as further increases in the numbers of growing pouits apparently placed too great a demand on the community's metabolite‐producing ability.
Genetic Variation in Quantitative Characters in Maize Inbred Lines, II. Effects on Performance in Single‐Cross and Double‐Cross Hybrids1
Authors: Higgs R. L. , Russell W. A.
Published: July 2010

Six inbred lines and seven single crosses involving these lines were obtained from four Corn Belt foundation seed stock organizations and the Iowa Agriculture Experiment Station. The genetic variation among the strains within inbred lines and among single crosses of the same pedigree was investigated. The inbred strains were compared in testcrosses with three unrelated inbred lines and the single crosses were compared in nine double‐cross hybrids. Tests in 10 environments, five locations for two years, revealed significant differences for percentage moisture among strain testcrosses within all inbreds and for yield in all except two of the inbreds. Strains included pollen restorer (Rf) and nonrestorer (rf) versions, except for two lines in which only rf versions were available. Significant variations were obtained for Rf vs. rf strain testcrosses, among Rf strain testcrosses, and among rf strain testcrosses. The Iowa Rf strain testcrosses were not different from the remaining Rf strain testcrosses for yidd, but the Iowa rf strain testcrosses compared with the remaining rf strain testcrosses were significantly different for yield within three of the six inbreds and for moisture within five of the six inbreds. Among strains within double crosses there were significant differences for percentage moisture in eight hybrids and for yield in four hybrids. Yield differences were great enough to be of practical importance in some cases, whereas moisture differences were not considered of practical importance even though many were statistically significant.