bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
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 cycleIn 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%
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.
Gene Action Conditioning Resistance to Northern Leaf Blight in Maize1
Authors: Hughes G. R. , Hooker A. L. 
Published: July 2010

SummaryThe 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.
Isolines in Cotton: Effects of Nine Dominant Genes1
Authors: Kohel R. J. , Richmond T. R. 
Published: July 2010

SummaryNine isolines of cotton, Gossypium hirsutum L., were developed by backcrossing lines carrying dominant marker alleles at a total of nine loci to Texas Marker‐1. The marker alleles were isolated into separate lines and backcrossed for eight generations to provide a common genetic background in which the effects of the individual marker loci could be evaluated and characterized. The effects of the qualitative characters on quantitative agronomic traits were determined for each line in a replicated performance test and compared to the performance of the recurrent parent. Certain quantitative traits of the isolines remained variable, and this variability was interpreted to be caused by linkage associations.
Microenvironment and Plant Characteristics of Corn (Zea mays L.) Planted at Two Row Spacings
Authors: Rumawas F. R. , Blair B. O. , Bula R. J. 
Published: July 2010

Development and yield of hybrid corn planted at 50‐ and 75‐cm row spacings and thinned to final stands of 44,000 plants/ha were studied. Micrometeorological parameters were recorded during the 3 weeks before and 3 weeks after anthesis. Carbohydrate levels of ear leaves were determined during the same period.Temperature, precipitation and solar radiation levels during the 1967 growing season were below recorded norreals. Air and soil temperatures, dew point temperatures, wind speeds, and carbon dioxide concentrations were similar at all canopy heights for the 50‐ and 75‐cm row spacings. Likewise, the daily maximums and minimums for the above listed parameters occurred at approximately the same time in the two row spacings.Carbohydrate percentages of plants grown in 50‐ or 75‐cm row spacings were similar. For both row spacings, diurnal changes in carbohydrate concentration were highly significant. Concentration of water‐soluble carbohydrates increased considerably during anthesis and early ear formation. Acid‐soluble carbohydrate concentration decreased during this same period. Under the climatic conditions of the 1967 growing season a wider row spacing resulted in better yield performance although these differences were not statistically significant.
F1 Hybrids Versus Random F5 Line Performance and Estimates of Genetic Effects in Spring Wheat1
Authors: Busch R. H. , Lucken K. A. , Frohberg R. C. 
Published: July 2010

Three hard red spring wheat (Triticum aestivum L.) crosses which had exhibited significant heterosis in a previous study were analyzed genetically by Hayman's generation mean analysis. Approximately 90 random F3‐ derived F5 lines were used as an agronomic comparison with the F1 hybrid generation and to determine if the genetic analysis based on parental, F1, F2, F3, F4, and backcross selfed generation means were of use in determining the possible results of selection.Results of the genetic analysis indicated that selection of individual plants should be effective for plant height and heading date. Less value was realized from the analysis of the three crosses for yield.F5 lines which performed significantly better than the F1 hybrid were found in each cross. One F1 hybrid failed to exceed the yield of its high parent, but both of the other hybrids were heterotic. F0 lines, derived from the best‐yielding F5 lines, and their respective parental F5 lines performed similarly when grown in the same experiments.
Influence of Drought Stress on Female Gametophyte Development in Corn (Zea mays L.) and Subsequent Grain Yield1
Authors: Moss G. I. , Downey L. A. 
Published: July 2010

Many abnormal embryosacs (43% of the total observed) were recorded in ears from corn plants that had been drought stressed twice over a period of 10 days during embryosac formation (treatment T3). Also, hermaphrodite spikelets were commonly observed. Yery few grains were produced by these plants. In ears of plants drought stressed once over a period of five days during embryosac formation (treatment T2), 15% of the observed embryosacs were abnorraal compared with only 2.5% in ears of the unstressed control plants. The grain yield of T2 plants was not significantly reduced. Both T2 and T3 treatments greatly delayed silking; in the former there was a lag of 13 days between anthesis and silk emergence, and 16 days in T3 as compared to 3 days in the controls. Plants were hand‐pollinated to prevent sterility caused by the lack of pollen during silking, so that the large reduction in grain yield by treatment T3 was due mostly to embryosac abortion.The surmise that femaleness of corn plants was reduced by drought stress because of a reduction in auxin levels was discussed.
Response of Different Rice Varieties to Gibberellin1
Authors: Harada J. , Vergara B. S. 
Published: July 2010

The response to gibberellin of 119 rice (Oryza sativa L.) varieties, including some dwarf mutants, was studied. The japonica, indica and dwarf mutants showed a negative correlation between the lengths of their second leaf sheaths and their responses to gibberellin. No such correlation was obtained with the javanica varieties.There was a negative relationship between gibberellin response and culm length. Some short varieties, however, showed a low response to gibberellin, indicating that lack of endogenous gibberellin is not the only factor responsible for dwarfness.
Combining Ability, Heritability, and Cytoplasmic Effects in Oats1
Authors: Muehlbauer F. J. , Marshall H. G. , Hill R. R. 
Published: July 2010

Combining abilities, heritabilities, and cytoplasmic influences in oats (Avena saliva L.) were investigated in the F1, F2, and F3 generations of reciprocal crosses involving winter and spring oat cultivars. Reciprocal differences between F1 hybrids in the greenhouse were frequent for days to first head, growth habit, number of tillers, and plant height; maternal effects were a major component of variation. The need for vernalization appeared to be under cytoplasmic control, and this requirement may have influenced the expression of the other characteristics measured in the F1 generation. Only a few significant differences between reciprocal populations were found in the F2 and F2 generations under field conditions, and maternal effects were of no general importance. Reciprocal effects were important in some cases for maturityand seed weight differences.Specific combining ability was significant for plant height and tiller number in the F1, but generally was not important in the F2 and F3, for maturity, plant height, straw strength, and yield. General combining ability was a consistent source of significant variation in the F2 and F3. Heritability estimates were highest for maturity and plant height and lowest for straw strength and yield. Combining ability and heritability estimates were influenced by the environment.
Effect of Leaf Pubescence on Transpiration, Photosynthetic Rate and Seed Yield of Three Near‐Isogenic Lines of Soybeans1
Authors: Ghorashy S. R. , Pendleton J. W. , Bernard R. L. , Bauer M. E. 
Published: July 2010

Apparent photosynthesis (AP), transpiration (TR) and seed yield were determined under field conditions for three near‐isogenic lines (isolines) of ‘Clark’ soybeans (Glycine max (L.) Merr.) differing in pubescence. AP of fully expanded leaves near the top of the plant and TR of individual plants were measured during the flowering stage.Seed yields artd AP rates were not affected by pubescence but the dense pubescent isoline had lower transpiration rates than the normal or glabrous isoline.