bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship of Pollen and Pistil Characteristics with Self‐ and Cross‐Compatibility in Alfalfa1
Authors: Rice James S. , Wang C. L. , Gray Elmer
Published: July 2010

The relationship of pollen and pistil characteristics to self‐ and cross‐compatibility was studied in ‘Buffalo’ alfalfa (Medicago sativa L.). Fifty‐three plants were selfed and 11 of these plants were crossed in a diallel design. Percentage of flowers producing pods, seeds/pod, and seeds/flower were used as compatibility indexes. Pollen tube length and pollen viability, as determined in vitro, and pistil length, style length, and number of ovules/ ovary were studied.

Pollen characteristics were more closely associated with self‐ and cross‐compatibility than were pistil characteristics. Pollen tube length was positively associated with the three indexes for both self‐ and cross‐compatibility. Pollen viability was positively correlated with each of the three indexes of cross‐compatibility, but only with percentages of flowers producing pods for self‐compatibility. None of the pistil characteristics was significantly correlated with any index of cross‐compatibility. Style length was negatively correlated with seeds/pod for selfcempatibility.

General, specific, maternal, and reciprocal effects were estimated from the diallel cross for each index as reported by Rice and Gray (13). Pollen tube length was significantly correlated with general effects for each index. Pollen viability was significantly correlated with general effects for seeds/pod and seeds/flower. None of the other effects was significantly correlated with the measured pollen or pistil characteristics.
Alfalfa Flower Aroma and Flower Selection by Honey Bees1
Authors: Loper G. M. , Waller G. D.
Published: July 2010

Honey bee (Apis mellifera L.) selection among flowers from seven clonal lines of alfalfa (Medicago sativa L.) presented in bouquets for three consecutive days was consistent from day to day and similar to results reported at a different locality. Flower aroma differences were noted as a possible basis for this selection. A gas chromatographic technique is described for collecting and separating components of flower aroma from intact plants. The flower aromas of three alfalfa clones were shown to differ greatly in their volatile components.
Influence of Solar Radiation and Date of Planting on Yield of Sweet Sorghum
Authors: Hipp Billy W. , Cowley W. R. , Gerard C. J. , Smith B. A.
Published: July 2010

Experiments were conducted to determine the influence of date of planting and solar radiatiou on yield of sweet sorghum stalks and sugar. Radiation received by the plants during the period between boot and early seed formation accounted for about 75% of the variation in yield. Maximum solar radiation in south Texas occurs during June, July, and August, consequently maximum yields were obtained from April, May, and June plantings.
Genetics and Test of Association of the Fluorescence Genes in Hexaploid Oats1
Authors: Sadanaga K.
Published: July 2010

Avena sativa L., cultivar ‘Cherokee’ carries F, one of two independent dominant genes controlling fluorescence of oat kernels. F is on chromosome 7 of the standard oat karyotype. The other dominant gene L is on a different chromosome.
Foliar Regrowth of Alfalfa Utilizing 14C‐Labeled Carbohydrates Stored in Roots1
Authors: Smith L. H. , Marten G. C.
Published: July 2010

Alfalfa (Medicago sativa L.) at the bud to early‐bloom stage was placed in a 14CO2 atmosphere for 24 hr to label carbohydrates being synthesized. Labeled carbohydrates that were translocated to the crown and roots within the 24 hr were considered as “stored” therein. Immediately following the labeling period, shoots were harvested and discarded, leaving a 5‐cm stubble. Thereafter, plants were harvested during the regrowth period at each of 5 stages — vegetative (15 and 30 cm), bud, first bloom, and 50% bloom and separated into shoots and roots plus crown.

Labeled carbohydrates initially stored in the root and crown were readily redistributed to developing shoots. Greatest redistribution occurred at the early vegetative stage and decreased with advancing maturity. Approximately 40% of the initially‐stored nonstructural carbohydrates were found in the shoots at the early vegetative stage. Only 13% of these labeled carbohydrates remained in the shoots at 50% bloom. A maximum of 9% of the stored carbohydrates was utilized for the synthesis of structural tissues in the developing shoots. This maximum appeared at the 50% bloom stage. Respiratory utilization by the entire plant of labeled stored carbohydrates continued with advancing shoot maturity, ranging from 26% at the youngest vegetative stage to 71% at 50% bloom.
Heterotic Performance and Combining Ability of Two‐Way F1 Soybean Hybrids1
Authors: Weber C. R. , Empig L. T. , Thorne J. C.
Published: July 2010

Eight attributes were measured in spaced F1 soybean (Glycine max (L.) Merrill) hybrids and their parents. The F1 hybrids gave an average of 13.4% heterosis for seed yield over their respective high parent in the 85 crosses evaluated. Nearly 77% of the hybrids exceeded the high parent yield. Seed size in large‐seeded ✕ large‐seeded hybrids was nearly 4% smaller than the large parent, while in small‐seeded ✕ small‐seeded crosses, the F1's and the larger‐seeded parents had about the same average seed size. Thus, an increase in seed number was largely responsible for the increase in seed yield of the F1. Wholeplant dry weight was larger and harvest index was smaller in the hybrids as compared with the high parent, indicating that, while the F1's produced more seed than the parents, their nonseed portion was unproportionately larger than in the parents. The hybrids approximated the midparent average in maturity, were generally shorter than the taller parent, and were not significantly different from the midparent mean in protein and oil contents.

Specific combining ability effects were significant for seed yield, maturity date, plant height, and oil content. Except for oil content, general combining ability estimates were significant and were two to six times larger than specific combining ability effects.
Cytogenetics of Resistance to Wheat Leaf Blotch (Septoria tritici) in Backcross Derivatives of an Agrotricum Line1
Authors: Rillo A. O. , Caldwell R. M. , Glover D. V.
Published: July 2010

Plants of a wheat‐Agropyron elongatum derivative (Purdue 39120A4), resistant to Septoria tritici, had chromosome numbers varying from 52 to 56, with a mode of 54. P39120A4 was crossed to a susceptible hexaploid wheat variety ‘Riley’ sib. The F1 plants had a modal chromosome constitution of 21″ ‐J‐ 6′, suggesting that P39120A4 commonly had three complete wheat genomes plus six pairs of Agropyron chromosomes. The F1 hybrids from reciprocal crosses were generally intermediate in reactions to S. tritici. However, the initial high resistance of P39120A4 retrogressed to intermediacy, while F1 reactions declined to susceptibility in the later part of the 4‐year study.

Segregation in F2 families generally fitted a ratio of seven resistant to nine susceptible. The backcross F1 plants fitted a ratio of one resistant to three susceptible, which suggested that resistance was on a single Agropyron chromosome transmitted 25% of the tune through the male and female gametes.

Resistant addition plants monosomic or disomic for the complete Agropyron chromosome or one of its isochromosomes were found among selected backcross F3 progenies. The disomic addition plants (22″) were cytologically stable, wheat‐like, and resistant at the seedling and mature stages. The other addition plants were cytologically unstable and exhibited resistance only in the seedling stage. The two identical isochromosomes in the di‐isosomic addition plant paired in only 27.4% of the sporocytes examined.

Irradiation was used in an attempt to induce transfer of resistance through translocations. No resistant plants with 21″ were recovered with a reciprocal translocation of an Agropyron segment or substitution of an entire Agropyron chromosome pair.
Effect of Outcrossing on Protein Quality, Kernel Weight, and Related Characters in Opaque‐2 and Floury‐2 Maize (Zea mays L.)1
Authors: Sreeramulu C. , Bauman L. F. , Roth Gary
Published: July 2010

Outcrossing of opaque‐2 and floury‐2 single crosses of corn, Zea mays L., to the same mutant but unrelated genotype, significantly increased kernel weight and weight of grain per ear of opaque‐2 and floury‐2 single crosses, and this increase was greater than in the normal counterparts. When sibbed, opaque‐2 and floury‐2 kernels had heavier germs than the normal kernels. Outcrossing also increased weight of endosperm in opaque‐2, floury‐2, and normal kernels; and germ weight in opaque‐2 and normal kernels. Protein and lysine content were apparently not affected by outcrossing.
Peroxidase Polymorphism in Cultivated Oats, Avena saliva L. and A. byzantina C. Koch1
Authors: Smith Rex L.
Published: July 2010

Three variant peroxidases in cultivated oats, Avena saliva L. and A. byzantina C. Koch, and their distribution among 29 winter and 33 spring oat cultivars and lines are reported. The winter cultivars were polymorphic in 3 variable isoperoxidases, and 6 enzyme combinations were present. The spring cultivars, with one exception, were not polymorphic for these enzymes and contained only one enzyme combination. It is proposed that the source of the polymorphism originated in A. byzantina, a species that has been used extensively as a source of germ plasm in breeding whiter oats. Two possible reasons for the lack of variation in spring oat isoperoxidases are discussed, namely, the existence of an association of the enzyme pattern found in spring oats with some physiological process having adaptive value to spring cultivars and genetic isolation.
Stimulation of Growth in Zinc‐Deficient Corn Seedlings by the Addition of Tryptophan1
Authors: Salami A. U. , Kenefick D. G.
Published: July 2010

L‐tryptophan added to the nutrient solution has been shown to eliminate retarded growth and deficiency symptoms resulting from omission of zinc in the growth of young corn seedlings (Zea mays L.). Compared to those which received zinc, seedlings treated with tryptophan had about a five‐fold reduction in tissue‐zinc content. No additive effect on growth was observed when tryptophan and zinc were supplied together. Addition of indole‐3‐acetic acid (IAA) failed to correct deficiency symptoms or restore growth rate in zinc‐deficient plants. The results indicated that optimal synthesis of tryptophan depended on suitable levels of zinc in the tissue and that the leaf‐streaking symptom was actually caused by low levels of this amino acid in the tissue under zincdeficient conditions.
Post‐Harvest Drying Rate and Germination of Kentucky Bluegrass Seed1
Authors: Canode C. L. , Law A. G. , Maguire J. D.
Published: July 2010

Kentucky bluegrass (Poa pratensis L.) seed was harvested with 26 to 29% moisture and dried in the swath. Different shade conditions were used to impose various drying rates. Seed germination was not influenced by the two different times of harvest (8 am and 8 pm) nor by any of the five drying conditions. The maximum exposure temperatures for the first day of curing varied from 24 to 49 C for the drying treatments.
A Technique to Determine Cold Hardiness in Plants1
Authors: Hodges H. F. , Svec L. V. , Barta A. L.
Published: July 2010

A device was constructed to provide continuous temperature gradients with a −40 C minimum temperature. A technique is described to determine the killing temperature of plants. Winter wheat and barley seedlings grown in the natural environment and in controlled environmental chambers were used to illustrate the application of this device for freezing plants and the technique for determining their level of hardiness.
Comparative Culm Elongation Rates of Isogenic Sorghum Lines Differing by a Single Height Gene (Dw3)1
Authors: Campbell L. G. , Casady A. J.
Published: July 2010

Results of a preliminary study comparing culm elongation rates of isogenic lines of ‘Japanese Dwarf’ broomcorn (Sorghum bicolor (L.) Moench) differing by a single height (Dw3) gene are reported. Culm elongation proceeded slowly until 36 to 39 days after seedling emergence and then proceeded rapidly until near the time of anthesis. The line with dominant Dw3 had a much more rapid and extensive internode elongation than did the line with dw3. A possible relationship between floral initiation and the period of rapid culm elongation and the differential rate of culm elongation is indicated.
Modifications of the Ozalid Paper Technique for Measuring Integrated Light Transmission Values in the Field1
Authors: Francis C. A.
Published: July 2010

The Ozalid paper technique for measuring integrated light values in the field has been modified in several ways. Blue and black Ozalid paper is suggested to replace the traditional sepia because of greater sensitivity and ease in evaluation of the meters. Use of several sheets of neutral gray plastic as filters extends the length of time which a set of meters may be used in the field. Filters may also decrease the variation in gram calorie measuremnts of a replicated series of samples. Plastic boxes, 5 cm ✕ 5 cm, with hinged plastic lids are filled with plastic sponge, and plastic black electrical tape used to exclude lateral light from the region of the meter. These modifications simplify light transmission measurements even under unfavorable weather conditions.
Factors Influencing Persistence and Depletion in Buried Seed Populations. II. The Effects of Soil Temperature and Moisture1
Authors: Schafer D.E. , Chilcote D.O.
Published: July 2010

Field and controlled environment studies were conducted to evaluate the effects of certain environmental factors on the persistence of buried seed of annual ryegrass (Lolium multiflorum Lain.), a free‐volunteering species; and perennial ryegrass (Lolium perenne L.), nonpersistent species. Buried seed of annual ryegrass persisted in both nondormant and dormant condition. Buried seed of perennial ryegrass lost virtually all viability after 60 days of burial in the field. This dissipation occurred largely via in situ germination. Dormancy was induced in annual ryegrass when seeds were buried in cold, wet soils. High soil temperature associated with intermediate soil moisture level was effective in depleting viable seed through in situ germination. Loss of buried seed viability increased with soil temperature and moisture.
Inheritance Studies in Interspecific Hybrids Between Carthamus flavescens and C. tinctorius1
Authors: Imrie B.C. , Knowles P.F.
Published: July 2010

Carthamus flavescens Spreng is an annual herbaceous weed, indigenous to the Middle East, and closely related to C. tinctorius L. (cultivated safflower). Inheritance of the following characters was found to be determined by a single gene each in interspecific crosses between these species: short vs. long rosette stage of growth, lobed vs. entire leaf margins, shattering vs. nonshattering of the achenes, white vs. pigmented achenes, presence vs. absence of pappus, and purple vs. green midveins of the cotyledonary leaves. The role of C. flavescens in the evolution of cultivated safflower is discussed.
Genetic Male Sterility for Hybrid Seed Production in Wheat
Authors: Gill B. S. , Anand S. C.
Published: July 2010

Partially male sterile stocks possessing different degrees of seed set ranging from 5 to 65% have been developed in wheat (Triticum aestivum L.). The degree of male sterility in these stocks is known to depend upon the cumulative effect of three recessive genes. It is proposed to use the stock with 5% seed set as the female for hybrid seed production. This stock can be maintained in isolation and its use would eliminate the necessity of restorer genes in pollinator lines.
Wheat and Barley Vernalization in a Precise Temperature Gradient1
Authors: Trione E. J. , Metzger R. J.
Published: July 2010

Rate of meristem elongation of the primary culm in winter wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) was a function of temperature and length of cold treatment. Elongation of the wheat meristems did not begin unless the seedlings had a minimum of 15 days at 5 to 8 C. Effectiveness of the cold treatment in wheat seedlings was maximum at 7 C but decreased very rapidly if the vernalization temperature was raised to 9 C or lowered to 3 C. The barley variety required a vernalization period greater than 12 days. Effectiveness of the cold treatment of barley seedlings was maximum at 9 C and decreased rapidly if the vernalization temperature was raised to 12 C or lowered to4 C.
Effects of Super Okra Leaf Shape on Boll Rot, Yield, and Other Characters of Upland Cotton, Gossypium hirsutum L.1
Authors: Andries J. A. , Jones J. E. , Sloane L. W. , Marshall J. G.
Published: July 2010

The effects of the super okra leaf shape on boll rot. yield, plant and fiber characters of Upland cotton, Gossypium hirsutum L., were investigated at three locations in Louisiana. Near isogenic populations of super okra leaf and normal leaf on each of three varietal backgrounds were used.

Super okra leaf shape, as an average of varieties and locations, caused a significant reduction in boll rot, yield, fiber length, and total leaf surface area in comparison with normal leaf cotton. Super okra leaf shape caused an increase in earliness, lint percentage, fruiting rate, and micronaire value, but had no effects or inconsistent effects on boll size, fiber length uniformity, fiber strength, and fiber elongation. The interactions of variety ✕ leaf shape and location ✕ leaf shape were significant for some of the characters studied.

A mixed population of super okra leaf and normal leaf plants in a 1:1 ratio was investigated. The mixed leaf population was found to have no advantage over the pure populations of the contrasting leaf shapes.
Genetic Diversity and Heterosis in Nicotiana. III. Crosses among Tobacco Introductions and Flue‐Cured Varieties1
Authors: Vandenberg Pieter , Matzinger D. F.
Published: July 2010

Crosses of flue‐cured varieties of Nicotiana tabacum L. to introductions of N. tabacum from South and Central American countries in the presumed center of origin of the species were evaluated at two locations in North Carolina. Heterosis in these crosses for most characters was greater than that found in crosses among flue‐cured varieties, was similar to that found for crosses of flue‐cured varieties to Oriental varieties, but considerably less than that obtained from crossing flue‐cured varieties to the presumed progenitor species. Diallel analyses of the data detected considerable general combining ability ✕ location interaction effects, significant variance of general combining ability for all characters, and significant variance of specific combining ability for five of nine characters evaluated.
Genetics of Isozyme Variants in Barley. I. Esterases1
Authors: Kahler A. L. , Allard R. W.
Published: July 2010

The 30 parents of barley (Hordeum vulgare L.) Composite Cross V (CC‐V), F1 and F2 progenies from crosses between selected parents, and progenies obtained by selling individuals from advanced generations of CC‐V were studied by starch‐gel electrophoresis. Data are presented demonstrating that the 21 esterase bands observed in plumule tissue of seedlings are governed by seven loci, designated EA‐EG; four codominant alleles were found for locus EA, three for loci EB and EC, and three for locus ED, plus a recessive null or silent allele. Loci EE, EF, and EG show either a single‐banded or null expression, with banded dominant to null. Loci EA, EB, and EC are tightly linked (recombination values EA‐EB = .0023, EB‐EC = .0059, EA‐EC = .0048). The ED and EG loci each segregate independently of loci EA, EB, and EC and also segregate independently of each other. There is extensive allelic polymorphism among the parents of CC‐V for the EA, EB, EC, and ED loci; only 3 of the 30 parents are monomorphic for all four loci whereas 6 arc polymorphic for one, two, or three loci, and 9 are polymorphic for all four loci. The EG locus, in contrast, is nearly invariant in the parents of CC‐V. The extent of polymorphism for loci EE and EF could not be determined precisely due to poor resolution obtained for these loci with the electrophoretic technique used during most of the present experiment. It was concluded that the esterase isozymes are useful research tools for determining the extent and geographical distribution of allelic variability in barley populations, and for studies of various factors involved in its development and maintenance.
Hill versus Row Plot for Testing Wheat Lines1
Authors: Khadr F. H. , Kassem A. A. , ElKhishen A. A.
Published: July 2010

Parents and 107 F4 lines derived from three wheat (Triticum aestivum L. em Thell) crosses were tested in hills and rows in 1967 and 1968. Comparisons of hill plot vs. row plot using means, ranges, mean squares, heritabilities, and correlations indicated that both techniques were equally efficient to discriminate among the wheat lines for heading date, plant height, seed weight, but not for yield.

The number of entries that were common in the extreme 25% portion of the population using each method appeared quite satisfactory to justify the use of hill plots for testing large populations.
Inbreeding and Heterosis in Red Clover1
Authors: Taylor N. L. , Johnston Karl , Anderson M. K. , Williams J. C.
Published: July 2010

The effects of inbreeding and heterosis in red clover (Trifolium pratense L.) were investigated in two experiments. Objectives were to study the effects of one generation of selfing on pseudo‐self‐compatibility (PSC) and on seed and forage characteristics, and to ascertain the degree of hybrid vigor obtained and its relation to persistence in single crosses of I1 parents.

In the first experiment, five I0 parental clones and four I1 clones from each of the five parents were compared in spaced‐planted field plots for PSC, cross‐compatibility, florets per head, and heads per plant. In all characteristics, some inbred families contained clones which equalled or exceeded their non‐inbred parents.

In the second experiment, a diallel cross was made among four I0 clones, and another among four I1 clones (one from each I0). Plants from these crosses and from open‐pollinated seed of the four I0's, and three varietal checks were compared for yield and persistence in spaced‐planted field plots, which also included vegetative propagules of the four I0 and four I1 clones. Hybrid vigor was expressed in the I1 single crosses, but their yields were no greater than the single crosses of the parental I0 clones. I1 clones yielded as much and were as persistent as I0 clones, but both yield and persistence were less than other non‐inbred materials, except for the varietal checks and O.P.'s of I0 clones. It was inferred that inbred parental lines may be maintained either by seed through PSC or by vegetative reproduction, and that yield and persistence lowered by selfing will be regained in single crosses.
Inheritance of Forage Yield and Certain Morphological and Fruiting Characteristics in Crownvetch1
Authors: Cope W. A. , Rawlings J. O.
Published: July 2010

We estimated general and specific combining ability variances (GCA and SCA) and certain phenotypic and genotypic correlations in crownvetch (Coronilla varia L.) by using an unbalanced partial dialleL The unbalanced design resulted when certain clones failed to flower and cross‐incompatibility was encountered. We made estimates by using data from a field planting of 108 crosses and the parental clones. Yield data were obtained from three hay cuts, and other measurements included flower date, seed set, stem angle, leaf and stem size, and final stand percent.

GCA estimates were significant for all traits, and SCA was significant for all but 2 of 12 traits. SCA estimates were small in relation to GCA for all characters except yield. The estimate of SCA for yield at the first hay cut was twice that for GCA, with SCA declining on successive cuts. Phenotypic correlations of total yield with flower date and seed set were low, but genotypic correlations were high and negative, indicating some difficulty in combining maximmn forage yield with adequate seed yield.

The phenotypic range and the high GCA estimates indicate the possibility of rapidly changing crownvetch populations by selection. If hay yield were the major consideration, a variety could be produced by a limited crossing system to exploit SCA. However, a cyclic selection system would be more practical with the present objective of developing a variety for a geographic area of marginal adaptation.
A Six‐Parent Diallel Cross Analysis of Coleoptile Elongation in Wheat, Triticum aestivum L.1
Authors: Parodi P. C. , Patterson F. L. , Nyquist W. E.
Published: July 2010

The F1 generation of a diallel cross among the soft red winter wheat genotypes ‘Vermillion,’ ‘Seneca,’ ‘Knox 62,’ ‘Benhur,’ ‘Arthur,’ and Purdue 5215 showed a significant expression of heterosis and heterobeltiosis in coleoptile elongation; all F1 progenies surpassed midparent and higher parent coleoptile lengths. However, this superiority was probably due in part to the larger seed size of the hand‐crossed seed, because the F2 progenies essentially equalled the midparental values. Genetic variation in coleoptile elongation appeared to be controlled largely by additive gene action. Regression coefficients of F1 on midparent and F2 on F1 were .957 to .783, respectively, indicating high heritability of the character. Study of small and large size seed fractions of the parents revealed a significant influence of seed size upon coleoptile elongation and seedling fresh weight.
Tester Performance Level for the Evaluation of Lines for Hybrid Performance1
Authors: Lonnquist J. H. , Lindsey M. F.
Published: July 2010

A total of 348 S1 lines of corn, Zea Mays L., (116 from each of three sources) were topcrossed to a high‐ and a low‐yielding tester. Based upon topcross performance, a high‐ and a low‐yielding group of lines were selected within each source for each topcross series. Subsequently, these selected groups of lines were evaluated in crosses with four elite lines as testers. In these latter trials the difference (H‐L) averaged greater for lines selected originally on the basis of the low‐yielding tester. Furthermore, lines selected as high yielding on the basis of crosses with the low tester averaged 5% higher yielding in testcrosses with the elite lines than those selected high on the basis of topcross performance with the high tester. The data substantiate previously published suggestions based upon theoretical considerations relative to the value of low‐yielding testers for line evaluation.
Fluorometric Assay of Free And Bound, cis‐ and trans‐σ‐Hydroxycinnamic Acid in a Single Plant Extract1
Authors: Haskins F. A. , Gorz H. J.
Published: July 2010

Fluorescence is measured on unhydrolyzed and hydrolyzed plant extracts, with and without prior ultraviolet treatment. Readings permit direct determination of free σ‐hydroxycinnamic acid (σ‐HCA), free trans‐σ‐HCA, total σ‐HCA, and total trans‐σ‐HCA. Levels of bound trans‐σ‐HCA and free and bound cis‐σ‐HCA are calculated by appropriate subtraction.
Location of a Gene in Maize Conditioning a Reduced Plant Stature1
Authors: Glover D. V.
Published: July 2010

A new reduced plant stature mutant (reduced‐2, rd2) in corn controlled by a single recessive gene was found to be non‐allelic to several dwarf and semidwarf characters previously described. Chromosomal translocations were used to locate the linkage group that carries the reduced gene. The results suggest that rd2 is located on chromosome 6.
Effect of Verticillium Wilt on Cotton Yield, Fiber Properties, and Seed Quality1
Authors: Bugbee W. M. , Sappenfield W. P.
Published: July 2010

Three varieties of upland cotton (Gossypium hirsutum L.) that differed in susceptibility to Verticillium alboatrum (microsclerotial form) were planted on three dates at 10‐day intervals. They were inoculated with V. albontrum by stem puncture in July, August, and September. Most of the damage to fiber properties and seed germination resulted from the August inoculation when bolls were in early stages of maturation. Most of the seed weight loss occurred following the September inoculation. No reduction in yield, fiber properties, or seed weight and only occasional loss of germination occurred following the July inoculation.

Poor quality seed from infected plants resulted in poor stands. The amount of damage correlated with known varietal susceptibility. This method of inoculation permitted detailed assessment of resistance to V. albo‐atrum under field conditions.
Effect of Seed Source on Seedling Vigor, Yield, and Lint Characteristics of Upland Cotton, Gossypmm hirsutum L.1
Authors: Peacock H. A. , Hawkins B. S.
Published: July 2010

Seed of ‘Empire WR 61’ and ‘Coker 100A WR’ Upland cotton (Gossypium hirsutum L.) from a common source were selfed or grown in isolated blocks for one generation at nine locations (sources). These seed were subsequently planted at Experiment, Georgia, in 1965 and 1966. Lint yield and seedling vigor data indicated that differences in progeny performance each year, and for both years combined, were associated with seed source. Seed source did not affect lint percent, seed index, boll size, fiber length, fiber strength, and fiber fineness either year. Correlations between progeny yield and vigor rating (r = 0.988 in 1965, r = 0.977 in 1966, and r = 0.988 for the combined data) were highly significant (P≤.Ol) indicating that vigor ratings were good indicators of progeny performance. Correlations between progeny yield and September minimum temperature at seed source (r = _0.519 in 1965, r = _0.553 in 1966, and r = _0.540 for the combined data), and between progeny yield and August rainfall at seed source (r = 0.524 in 1965, r = 0.535 in 1966, and r = 0.532 for the combined data) were significant (P≤.05) and each accounted for about 27% of the variability among seed sources. Higher temperatures and lower rainfall were associated with lower yield and poorer seedling vigor.
Inheritance of in vitro Digestibility in Smooth Bromegrass1
Authors: Ross J. G. , Bullis S. S. , Lin K. C.
Published: July 2010

The potentially useful variability for selection towards greater digestibility within a breeding nursery of smooth bromegrass (Bromus inermis Leyss.) was investigated by estimating the additive genetic effects for in vitro digestibility in a 6‐clone diallel cross. General combining ability was found to be a highly significant source of variation in determinations made on both the 1965 and 1967 harvests. An estimate of heritability obtained by doubling the regression of array means on the corresponding parental means was high, h2 = 1.06. Though correlations between such agronomic characters as height and seed set with in vitro digestibility were negative, they were low enough to make possible the selection of a more digestible synthetic variety with desirable agronomic characteristics.
Exotic Germplasm for Yield Improvement in 2‐way and 3‐way Soybean Crosses1
Authors: Thorne J. C. , Fehr W. R.
Published: July 2010

We evaluated homozygous populations froin 2‐way adapted × exotic and 3‐way (adapted × exotic) × adapted soybean (Glycine max (L.) Merrill) crosses for seed yield. The average yield of our 3‐way populations was significantly greater than the 2‐way population mean, but differences were not significant in some 2‐, 3‐way sets. Mean population performance was generally predictable from parental performance, although a masking inhence of genes from the third parent was observed in the 3‐way crosses.

Estimates oC genetic variance for 3‐way populations generally were larger than for 2‐way populations for yield. Transgressive segregation was observed in all populations, but in most 2‐, 3‐way sets, the 3‐way cross produced more of the superior lines for yield than the 2‐way cross.
Multiple Chemical Treatment of Cotton Seed, Effects on Seedling Survival
Authors: Ranney C. D.
Published: July 2010

Multiple chemical seed treatments which included fungicides and combination of systemic fungicides and insecticides were of value for pest control in cotton, Gossypium hirsutum L. Nonmercurial protectant fungicides were as effective as organic mercury compounds. Inclusion of a systemic fungicide in the treatment combination significantly increased plant survival. Inclusion of a systemic insecticide in the treatment combination resulted in consistent reductions in plant survival. Reduction in plant survival was minimized when a systemic fungicide was included in the treatment combination. Significant interactions between chemical treatments indicate a need to identify desirable combinations of chemicals for seed treatment.
Screening Rice for Resistance to the Planthopper, Sogatodes oryzicola (Muir)1
Authors: Jennings Peter R. , Alicia Pineda T.
Published: July 2010

Studies were conducted on resistance in rice (Oryza sativa L.) to direct damage caused by the planthopper, Sogatodes oryzicola (Muir). Reistance was expressed throughout the growing period of the plant. Nymphs, males, and females all caused damage and killing of susceptible rice varieties. Resistant to the insect was independent of resistance to the hoja blanca virus (HBV) vectored by the same species. A mass screening technique for evaluation of large numbers of varieties or plant selections was developed along with a scale for evaluation of damage.

A survey of 534 varieties indicated that about 20% were highly resistant or resistant, 40% were intermediate, and 40% were susceptible. All resistant varieties were indicas from southeast Asia which showed little or no damage while susceptible ones were killed. Resistance appears to be highly heritable, is easily recombined with other agronomic traits, and is unassociated with plant pubescence. It is believed that resistance to the planthopper will protect varieties in the field from appreciable virus damage, even though the variety is susceptible to hoja blanca when the viruliferous insects are obliged to feed on it.
Effect of Resistant Rice Plants on Multiplication of the Planthopper, Sogatodes ozyzicola (Muir)1
Authors: Jennings Peter R. , Alicia Pineda T.
Published: July 2010

Studies were conducted to determine the effect of resistant rice plants (Oryza sativa L.) on the multiplication of the planthopper Sogatodes oryzicola (Muir). Plant resistance affected all phases of the life cycle of both nonvirulifcrous and viruliferous insects. Resistance reduced the number of eggs deposited and the number of nymphs hatched, lowered nymphal survival, prolonged the nymphal period, and reduced adult longevity. Because of more eggs deposited per day, greater egg fertility, and increased nymphal survival, susceptible plants supported about 10 to 12 times as many nymphs as did resistant plants. Of these, about 3 to 5 times as many nymphs became adults on susceptible rice as on resistant rice.
Colchicine‐Induced Polyploids from Cell Suspension Cultures of Sugarcane1
Authors: Heinz Don J , Mee Grace W. P.
Published: July 2010

A high percentage of endoreduplicated chromosomes resulted when cell suspension cultures of sugarcane (Saccharum officinarum L.) were treated with colchicine. Cytological examination of 46 plants from H 57‐1627 callus differentiated from the colchicine‐treated cells showed 22 to be polyploids, 2 to be mixoploids, and 22 to be diploids. This is the first report of chromosome doubling in commercial sugarcane hybrids. The proposed method of treating cells in suspension with colchicine should prove beneficial to sugarcane breeders and other breeders interested in obtaining polyploid plants.
Use of R Alleles in Obtaining the Modified Protein Double Mutant (Opaque‐2, Floury‐2) in Zea Mays L.1
Authors: Lambert R. J. , Cochran D. E.
Published: July 2010

Certain R alleles of maize were used to test for the presence of the floury‐2 allele in putative double mutants opaque‐2, floury‐2. With the use of double pollinations a generation of testcrossing could be eliminated for floury‐2. The results indicate the Rnj allele could be used to advantage in the genetic backgrounds tested.
Morphology of Pubescence in Soybeans and Its Relationship to Plant Vigor1
Authors: Singh B. B. , Hadley H. H. , Bernard R. L.
Published: July 2010

The morphology and performance of near‐isogenic lines of soybeans with monogenically different pubescence types were investigated. Hairs of the normal, dense, and sparse types are similar, each consisting of a very long (1‐ to 3‐mm) cylindrical cell with one, two, or three basal cells. Hairs of curly pubescence are similar initially to normal hairs, but then become flat, curl, and tend to fall off. Glabrous plants have hair stubs made up of one to seven nearly isometric cells. Puberulent plant hairs consist of a single elongate (0.1 mm) apical cell with one, two, or three basal cells.

Marked growth differences in the field were associated with differences in infestation by the potato leafhopper (Empoasca fabae (Harris)). Dense pubescent plants grew tallest followed in descending order by normal, sparse, curly, and glabrous types. Yields of lines with normal, dense, and sparse pubescence were similar, and superior to yields of the curly and glabrous lines.
Evaluation of 10 Generations of Mass Selection for Corn Earworm Resistance1
Authors: Zuber M. S. , Fairchild M. L. , Keaster A. J. , Fergason V. L. , Krause G. F. , Hilderbrand E. , Loesch P. J.
Published: July 2010

Mass selection for resistance to corn earworm (Heliothis zea (Boddie)) was made in two corn, Zea mays L., populations (Synthetics C and S) grown in isolation for 10 generations during the period 1956 to 1965. Plantings were made on or about 15 June to enhance the chances for a high infestation of earworm. From each planting at least 1,000 ears were classified into three categories: (1) penetration of the earworm to the kernel resulting in damage, (2) earworm entry into the silk channel but no kernel damage, and (3) no evidence of earworm entry into the silk channel. Ears from class 2 were used for planting the subsequent cycle

In 1965, remnant seed of five cycles (spanning the 10 generations) for each synthetic was increased by sibpollinating approximately 200 plants. Evaluation tests were grown at two locations in 1966.

Mass selection in both synthetics was effective. for Synthetic C the percentage of ears with kernel damage was reduced from 80.8% (1957) to 58.7% (1965), a reduction of 2.76% per generation. The percentage of ears with earworm damage for Synthetic S was reduced from 64.5% (1956) to 39.2% (1965). The average reduction per generation was 2.81%
Yield Component Compensation — Alternative Interpretations1
Authors: Adams M. W. , Grafius J. E.
Published: July 2010

The patterns of response to selection in two barley populations (Hordeum vulgare L.) for yield and its components were interpreted by Rasmusson and Cannell as indicative of genetic linkage. We propose an alternative explanation based on an oscillatory response of components due to the sequential nature of components development and a limitation of environmental resources. Use is made of a recurslon equation which under specified conditions leads to the expectation of oscillatory behavior of components. The data of Rasmusson and Cannell conform to the oscillatory hypothesis.
A Diallel Analaysis of Several Agronomic Traits in Upland Cotton (Gossypium hirsutum L.)1
Authors: Verhalen Laval M. , Morrison Walter C. , Al‐Rawi Baha A. , Fun Kwee‐Chong , Murray Jay C.
Published: July 2010

Diallel analyses of seed cotton yield per plant, lint yield per plant, lint percent, and earliness were conducted on 10 selected wtrieties of upland cotton (Gossypium hirsutum L.) and the 45 F1 crosses among them in 1965 and on the parents, Fl's, and their 45 F2 progenies in 1966 using the procedure developed by Jinks and Hayman. A partial failure of the assumptions was observed for each trait. However, lint percent more nearly fulfilled the assumptions than did the measurements for yield or earliness. Epistasis did not appear to be a factor in any of those failures. A genotype by environment interaction lot the additive components of variation was noted for lint percent. A single interaction for the dominance components influenced earliness.

All traits appeared to be governed by a weighted overall degree of dominance in the overdominanee range except for lint percent in the 1966 F1 where partial dominance was indicated. The magnitudes of their heritability estimates indicated that mass selection on a plot mean basis when plots are small would not be very effective in altering any of these traits. Pedigrees, sib tests, or progeny tests (or various combinations among them) almost certainly Will be required to improve seed cotton yield, lint yield, or earliness in this material and may be necessary to improve lint percent.

The reliability of F1. diallel estimates from year to year at a single location was investigated. Comparisons between F1's and F2's were also made.
Chilling Injury in Cotton Seedlings: Changes in Permeability of Cotyledons1
Authors: Guinn Gene
Published: July 2010

Chilling at 5C caused cotton seedlings (Gossypium hirsutum L.) to wilt and apparently increased permeability of cotyledonary membranes. Chilling greatly increased the amounts of reducing sugars, ninhydrin‐positire material, and ionic material which subsequently leached from cotyledons when they were floated in 0.2M mannitol after the chilling treatment. Permeability did not increase until seedlings were chilled for at least 3 hr. Moisture stress, caused by decreased water uptake at low root temperature, may have affected permeability of cotyledons. Cold‐hardened seedlings, upon chilling, showed less visible injury and less leakage from cotyledons than control seedlings.
Carbohydrate Trends in Alfalfa (Medicago sativa L.) Roots under Several Forage Harvest Schedules1
Authors: Reynolds John H.
Published: July 2010

Nonstructural carbohydrate trends in ‘Buffalo’ alfalfa (Medicago sativa L.) roots were compared in six harvest frequencies (8, 6, 5, 4, 3, and 2 cuts per year) for 2 years at Knoxville, Tenn. Carbohydrate levels in the first year were generally lowest when cut eight times, and the stand in this treatment was very sparse at the end of the first year. A depletion and replacement pattern of carbohydrates between harvests was usually evident, especially in the four‐cut harvest frequency. The greatest drop in carbohydrate concentration usually occurred after the first harvest of the year. Under a uniform harvest schedule in the third year, the two‐cut, three‐cut, and four‐cut treatments had the most vigorous and productive stands. Yield in the third year did not have a significant positive correlation with carbohydrate concentrations at the end of the second year.
Cytology and Agronomic Performance of Lolium‐Festuca Hybrid Derivatives1
Authors: Webster G. T. , Buckner R. C.
Published: July 2010

Interpollination of colchicine‐induced 56‐chromosome amphiploids selected for fertility and seed set through six generations resulted in meiotically unstable plants representing nearly the entire range of 42 to 56 chromosomes. Within one line, meiotically stable plants (2n42) were recovered from crosses between amphiploids and F1 annual ryegrass ✕ tall rescue. Several of these were superior to tall rescue in seedling vigor, total forage yield and palatability. Meiosis of progenies of reciprocal cross combinations tended to be similar to that of the maternal parent as measured by the number of micronuclei perpollen quartets.
Resistance of Selected Alfalfa Strains to Ozone1
Authors: Howell R. K. , Devine T. E. , Hanson C. H.
Published: July 2010

Fourteen strains of alfalfa, Medicago sativa L., were evaluated for sensitivity to ozone. Plants were exposed to 20 parts per hundred million (pphm) v/v for 4 hr at 26C, 92% relative humidity, and an illumination of 2,000 ft‐c. The variety ‘Team,’ developed partially in greenhouses and routinely selected for resistance to foliar injury, was more tolerant of ozone than varieties not so selected. We believe that this is the first report demonstrating the effectiveness of greenhouse selection, during periods of high levels of air pollutants, as part of a program to expedite the development of plant varieties resistant to phytotoxicants.
Gene Action Conditioning Resistance to Northern Leaf Blight in Maize1
Authors: Hughes G. R. , Hooker A. L.
Published: July 2010

The nature of gene action conditioning the quantitative type of resistance in maize (Zea mays L.) to Northern leaf blight caused by Helminthosporium turcicum Pass. was studied in crosses between four Australian resistant inbred lines (D21, HB, 21H, and 25) and three tester inbred lines (susceptibles H10 and 701, and moderately resistant Oh43). Populations composed of the P1, P2, F1, F2, BC1P1 and BC1P2 generations were studied for the 12 possible crosses in 1966 and with the addition of F3, BC1P1S and BC1P2S families for four crosses in 1967.

Additive, dominance, and epistatic gene action were detected by analysis of generation means. Additive gene action was of major importance in all crosses in both years. The relative importance of non‐additive effects was generally small and varied with the population involved and, to a lesser extent, with the year of study. Although biased by limitations in experimental and analytical design, estimates of components of genetic variance were in general agreement with the results of the generation mean analysis.

It was concluded that leaf blight resistance in these lines was conditioned by a relatively low number of genes, primarily additive in effect. Breeding for resistance to this disease should be effectively accomplished by such simple procedures as phenotypic recurrent selection or mass selection.
Yield Stability of Selected Spring Wheat Cultivars (Triticum aestivum L. em Thell) in the Uniform Regional Nurseries, 1959 to 19681
Authors: Joppa L. R. , Lebsock K. L. , Busch R. H.
Published: July 2010

Yield data from Uniform Regional Spring Wheat Nurseries (URSWN) grown at 15 to 20 locations in the North‐Central USA and Canada in each of the 10 years, 1959‐1968, were subjected to regression analysis. Within a year, nurseries consisted of a standard set of cultivars and experimental lines. The regression of cultivar or line yield on the average yield of the nursery (b) and the mean square deviation from regression (s̄d2) were calculated for each cultivar or line in each of the years. Each cultivar tended to have its own characteristic value for b and for s̄d2. We defined specific genotype‐environment interaction as one which was due to a specific cause, such as susceptibility to a pathogen. The magnitude of s̄d2 was an excellent indicator of specific genotype‐environment interactions. The use of regression analysis on data from uniform regional nurseries could materially assist the plant breeder in making decisions regarding cultivar release.