bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heritability and Interrelationships of Grain‐Protein Content with Other Agronomic Traits of Sorghum1
Authors: Crook Wayne. J. , Casady A. J. 
Published: July 2010

Forty grain sorghum (Sorghum bicolor (L.) Moench) hybrids were produced by crossing each of 4 cytoplasmic male‐sterile lines with 10 diverse restorer lines. The parents and their hybrids were grown at four locations in 1972. Characters studied included protein percentage, grain yield, days to 50% bloom, height, panicle exsertion, leaf area, panicles per pl,ant, kernel weight, and test weight.Location significantly affected all characters except test weight in the hybrid populations. The genetic variance was significant for all characters measured. The specific combining ability, estimated by the male) ✕ female interaction, was significant for protein percentage, days to 50% bloom, height, panicle exsertion, panicles per plant, kernel weight, and test weight.Heritability estimates were calculated from variance components and midparent‐offspring correlation. High heritability estimates were obtained from correlations for protein percentage, height, and panicles per plant; medium heritability estimates were obtained for yield and kernel weight; and low heritability estimates were obtained for day to 50% bloom, panicle exsertion, leaf area, and test weight. Heritability estimates for all characters were high when calculated from variance components.
Simulated Selection in Autotetraploid Populations. I. Computer Methods and Effects of Linkage1
Authors: Swanson M. R. , Dudley J. W. , Carmer S. G. 
Published: July 2010

A computer simulation model for mass selection in a random mating autotetraploid population was presented. Selection was based on a single quantitative trait controlled genetically by 40 genes, 4 on each of 10 chromosomes. The model allowed for arbitrary gene frequency, double reduction, linkage, dominance, epistatic deviations involving two loci, population size, intensity of selection, and environmental variance. Effects of mutation, migration, and natural selection were ignored.Preliminary results revealed that linkage affected selection response in diploid and autotetraploid populations about equally when genetic variance was primarily additive. With dominance, linkage had a greater effect on diploids.
Simulated Selection in Autotetraploid Populations II. Effects of Double Reduction, Population Size, and Selection Intensity1
Authors: Swanson M. R. , Dudley J. W. , Carmer S. G. 
Published: July 2010

Effects of double reduction, population size, and selection intensity on response to mass selection in a random mating autotetraploid population were studied by computer simulation. Results were compared to diploids. Selection was based on a single quantitative trait controlled genetically by 40 loci, ignoring the effects of mutation, migration, and natural selection. Six genetic models, with varying levels of additive, dominance, and epistatic variance were compared.In models with small dominance effects, double reduction increased heritability by increasing additive genetic variance, thus increasing selection response. In models with dominance deviations, selection response was not affected by double reduction.Genetic drift was a major factor in limiting total selection response when the effective population size was 10 or less. Diploids were affected more by genetic drift than autotetraploids.Changes in genetic variance over generations of selection varied with the genetic model, selection intensity, and initial gene frequency. Peculiar trends were noted for some models due to a mix of initial gene frequencies. Of several measures of heritability compared, parent‐offspring regression on a random sample of parents and their offspring predicted selection gain best.
Histological Studies on Five Male‐Sterile Strains of Upland Cotton1
Authors: Murthi Anishetty N. , Weaver J. B. 
Published: July 2010

Microsporogenesis and pollen development in one cytoplasmic male‐sterile and four genetic male‐sterile strains of Upland cotton (Gossypium hirsutum L.) were studied in comparison with a male‐fertile variety.In the cytoplasmically male‐sterile Upland cotton with the G. harknessii cytoplasm, there was disorganization of tapetal cells and coalescence of pollen mother cells (PMC's) during the premeiotic stages.In the Ms4 dominant genetic male‐sterile anthers, degeneration of microsporocytes was observed before or shortly after the initiation of prophase I. The tapetal cells were reduced in size in some of the anthers.In another dominant genetic male‐sterile, Ms7, meiosis appeared normal in the majority of the PMC's. The abortion of microspores was noticed during formation of the pollen wall. There was no observable malfunctioning of the tapetum.In the double recessive ms5ms6 male‐sterile anthers, vacuolation of developing microspores led to their degeneration. Nutrient deficiency of several kinds might have been the cause of vacuolation and abortion of pollen.In Rhyne's double recessive male‐sterile unthers, premature degeneration of the tapetum caused the abortion of pollen in most locules. In a few locules viable pollen was produced but the anthers were nondehiscent. Seeds were produced when pollen from the indehiscent anthers was released by crushing and dusted on other male‐sterile plants.
Diallel Crosses Among Maryland Cultivars1 of Tobacco1
Authors: Fan C. J. , Aycock M. K. 
Published: July 2010

Five cultivars and the diallel set of 10 F1 hybrids of tobacco (Nicotiana tabacum L.) were grown at 2 locations in 1967. The diallel was expanded in 1968 to include 7 cultivars and 21 F1 hybrids. Also in 1968, F1 and F2 hybrids from the 5‐parent diallel were grown at one location in order to obtain estimates of inbreeding depression. For both years, a significant heterotic response was observed for four agronomic traits. On the average, the F1 hybrids produced more yield and dollars per hectare, had a higher price ($/kg), and flowered earlier than the cultivars. A significant inbreeding depression was found with the F2 hybrids for value ($/ha), price ($/kg), and days to flower.From the 7‐parent diallel, estimated variability for general combining ability was significant for 6 of the 10 traits studied, but specific combining ability estimates were small and nonsignificant. F1 hybrids in the 5‐parent diallel did not vary significantly.
Stability Indexes of Radiated and Nonradiated Oat Genotypes Propagated in Bulk Populations1
Authors: Fatunla T. , Frey K. J. 
Published: July 2010

Two lines of descent were established from an F3 bulk lot of oats (Arena sativa L.) initiated by mixing seeds from 250 crosses. For one line of descent, seeds were radiated with thermal neutrons or X‐rays from F3 through F6, and these treatments were followed by five generations of bulk propagation with no artificial selection. The other line was propagated for 10 generations with no artificial selection. Twenty random strains from each of four generations from the radiated (F7, F8, F9, and F11) and five from the nonradiated (F3, F6, F7, F8, and F12) line of descent, and ‘Nodaway’ cultivar were used to measure stability indexes for grain yield, plant weight, harvest index, plant height, 100‐seed weight, and seed numbers in the various generations.Mean regression stability indexes for grain yield decreased from 1.17 to 1.02 in the nonradiated line, and increased from 0.82 to 1.04 in the radiated line of descent over time. Generally, data on oat strains from the radiated line fitted the linear regression model better than those from the nonradiated one. The changes in mean regression stability indexes for plant weight paralleled those for grain yield, but no trends in this statistic occurred for other traits.Genotypic variances among strains within generations were sporadic for all traits in both lines of descent. for grain yield, seed number, and plant height there were consistent expansions in the genotype ✕ environment interaction variances within generations. This was primarily due to the regression stability indexes among lines becoming more diverse over time. The contributions of deviations from regression to the interaction variance remained relatively constant over generations in both lines of descent.Means and regression stability indexes for oat strains within generations were highly and positively correlated for grain yield, seed number, bundle weight, and plant height.
Effectiveness of Recurrent Selection for Corn Stunt Resistance in a Maize Variety1
Authors: Scott Gene E. , Rosenkranz Eugen E. 
Published: July 2010

Three methods of selecting parents to be used in a recurrent selection program were compared for their effectiveness in increasing the level of resistance to corn stunt within a corn (Zea mays L.) population. Selection methods were: (1) selecting the best plant in the best 10 of 463 S1 progeny rows, (2) selecting the best 23 S3 progenies derived from the original 463 S1 progenies, and (3) selecting the best 10 of 100 S1 progenies that were evaluated in a replicated test. All tests were conducted under conditions of natural infection by the disease agents.Each method of selection was effective. Selecting parents on the basis of results obtained from a replicated test was the most efficient procedure. In the improved population after one cycle, 21% of the plants were infected with corn stunt, compared with 52% diseased plants in the original population. Our results showed slightly more effectiveness in improving the population for corn stunt resistance than predicted.
Light Intensity During Leaf Growth Affects Chlorophyll Concentration and CO2 Assimilation of a Soybean Chlorophyll Mutant1
Authors: Koller H. R. , Dilley R. A. 
Published: July 2010

An evaluation was made of leaf diffusive resistance and chlorophyll concentrations of dark green (normal) and pale green (chlorophyll deficient) phenotypes of a soybean [Glycine max (L.) Merrill] mutant when grown 10‐ and 30‐klux light intensities. When grown at the 10‐klux intensity the two leaf types had similar mesophyll and total CO2 diffusive resistances and similar net photosynthetic rates per unit leaf area at normal ambient CO2 concentrations (e.g., 300 µl/liter). Chloropyhll concentration of the pale green leaf was one‐fourth that of the dark green leaf. On a chlorophyll basis, rate of CO2 fixation was four times faster in the pale green type than in the dark green type. The similarity in net photosynthetic rates per unit leaf area of the two phenotypes when grown at the 10‐klux light intensity was the result of (1) similar CO2 diffusive resistances and (2) the ability of the photosynthetic apparatus of the pale green leaf to fix CO2 as rapidly as that of the dark green leaf, in spite of a much lower amount of chlorophyll.When grown at the 30‐klux light intensity, chlorophyll concentration of the pale green phenotype progressively declined, to one‐tenth the amount at the 10‐klux intensity. Chlorophyll concentration of the dark green phenotype was not significantly affected by light intensity. Photosynthesis of the pale green leaf grown at the 30‐klux intensity became CO2 saturated at concentrations well below 300 µl/liter. Therefore, light intensity during leaf growth strongly influenced the relative CO2 assimilation rates of the dark green and pale green phenotypes.
Selection in Six Crops of Sugarcane. II. Efficiency and Optimum Selection Intensities
Authors: James N. I. , Miller J. D. 
Published: July 2010

Selection was applied for stalk number, stalk diameter, and Brix in six crops of a population of 376 sugarcane (Saccharum sp.) clones with intensities from 2 to 100%. In both cost and land use, efficiency of selection for stalk number was somewhat greater in the plant crop of seedlings and 1.2‐m clonal plots than in the first ratoon crops. For stalk diameter, efficiency was equal in the plant and ratoon seedling crops and greater in the plant crop than in the ratoon crop of 1.2‐m clonal plots. Selection efficiency for Brix was somewhat greater in the ratoon crop than in the plant crop of seedlings and about equal in both crops of 1.2‐m clonal plots.The optimum intensity for independent selection of stalk number and stalk diameter was 40% in both plant and first ratoon crops of seedlings. The optimum selection intensity for Brix in the plant crop of seedlings ranged from 30 to 50% and in the first ratoon crop of seedlings was 40%. In the plant crop of 1.2‐m clonal plots, the optimum selection intensity was 50% for the three characters. In the first ratoon crop, optimum selection intensities were 60, 40, and 40% for stalk number, stalk diameter, and Brix, respectively.The optimum simultaneous selection intensity for the three characters in the plant crop of seedlings ranged from 4.8 to 8% and was 6.4% in the first ratoon crop of seedlings. Optimum selection intensities in the 1.2‐m clonal plots were 12.5% and 9.6% in the plant and first ratoon crops, respectively.At the optimum selection intensities, gains from selection were 8 to 10% for stalk number and diameter and 4 to 5% for Brix.
Inheritance of Kernel Fatty Acid Composition Among Six Maize Inbreds1
Authors: Widstrom N. W. , Jellum M. D. 
Published: July 2010

Three single crosses among six dent corn (Zea mays L.) inbreds, and segregating generations, were produced for investigation of the inheritance of five major fatty acid components by the method of single kernel analysis. Generation mean analysis showed that additive variation was predominant for palmitic, oleic, and linoleic acid composition, whereas additive and dominance sources of variation were of about equal importance for stearic acid. Differences were nonsignificant between inbreds for linolenic acid composition; genetic effects could not be determined. Individual kernel analyses showed that differences in palmitic and oleic acids of the inbreds Ab26A and X‐187 were each controlled mainly by a single gene, though probably not the same gene. The gene controlling high palmitic acid in Ab26A was partially dominant whereas the gene controlling high oleic acid composition showed almost complete dominance. The data did not show single‐gene control of linoleic acid in this cross.A two‐factor hypothesis, with one factor showing partial dominance and the other no dominance for low linoleic acid, best explains the difference in linoleic acid of the inbreds GE82 (low) and R196 (high).
Heterosis and Inbreeding Estimates in Safflower1
Authors: Yazdi‐Samadi Bahman , Sarafi A. , Zali A. A. 
Published: July 2010

Estimates of heterosis and inbreeding depression in safflower (Carthcmus tinctorius L.) were obtained for seven traits: flowering time, plant height, yield, seed weight, percentage of empty seeds, embryo percentage, and oil percentage. Selfed and single‐cross hybrid progenies were compared in two experiments, one involving five varieties and the other seven.In one experiment some of the hybrids were significantly superior to their best parents for height, yield, seed weight, and oil percentage. Inbreeding depression was observed only in about 10% of the cases. In a second experiment significant heterotic effects were observed for flowering time, height, seed weight, and oil percentage. Inbreeding depression was present in about 11% of the cases. Reciprocal effects were not generally significant, suggesting that cytoplasmic effects are not important in safflower.
Distinguishing Characteristics of Crambe Abyssinica and C. Hispanica
Authors: White George A. 
Published: July 2010

Morphological characteristics and chromosome numbers were compared to clarify the distinction between Crambe abyssinica Hochst. ex R. E. Fries and C. hispanica L. Chromosome numbers and basal leaf shapes proved to be the most reliable distinctive features. Length and structure of the lower fruit segment do not give a clear species distinction. Three accessions including the cultivar ‘Indy’ that were introduced as C. hispanica were re‐identified as C. abyssinica. PI 370747 is the first recorded wild collection of C. abyssinica from Turkey. C. hispanica var. glabrata (DC.) Coss. differed from C. hispanica in chromosome number (n=15 and n=30), pericarp and seedcoat color, fruit size, and in length of the lower segment of the fruit.The average erucic acid content, just under 60%, in the seedoils of C. hispanica (PI 337996) and C. hispanica var. glabrata (PI 372928) was quite similar to that of C. abyssinica.
Variation and Covariation of Agronomic and Quality Traits in Two Spring Wheat Populations1
Authors: Dyck P. L. , Baker R. J. 
Published: July 2010

Random F5‐derived F7 lines from each of two related crosses of spring wheat, Triticum aestivum (L.) em. Thell., were grown in replicated tests in each of 2 years. Three types of traits were measured: a) classification traits (rust resistance, awnedness, waxiness, spike type, spike density, and lodging resistance); b) agronomic measurement traits (height, maturity, kernel weight, and yield); and c) quality measurement traits (flour nitrogen, sedimentation value, mixograph development time, mixograph peak height, and centrifuge absorption).There were no significant differences between the two crosses, ‘Manitou’ ✕ R37 and ‘Pembina’ ✕ R37, in estimates of variance components nor heritabilities. Of 60 comparisons between classification and measurement traits, only three were significant in Manitou ✕ R37 and four in Pembina ✕ R37. There was no significant relationship between yield and awnedness nor between yield and nitrogen content. The cross mean differed significantly from the mid‐parent value in only one of 14 cases. Estimates of genetic variances did not differ between crosses for any of the traits studied.
Evaluation of Eleven Thermal Unit Methods for Predicting Soybean Development1
Authors: Major D. J. , Johnson D. R. , Luedders V. D. 
Published: July 2010

Dates of emergence, flowering, beginning pod fill, termination of flowering, and physiological maturity were recorded for two soybean [Glycine max (L.) Merr.] cultivars from each of the maturity groups I to V. The cultivars were planted on five dates at three Missouri locations in 1971, 1972, and 1973, and at weekly intervals at Columbia, Mo., in 1972 and 1973. Daily maximum and minimum temperatures were used to calculate five thermal unit methods with no base temperature subtracted, four methods with a base temperature subtracted, and two methods using quadratic formulas.Thermal units with a base temperature subtracted, including the “growing degree day method” used by the corn industry, and thermal units using quadratic formulas were the best for predicting flowering. The number of thermal units was not better than calendar days for predicting post‐flowering development. Prediction of flowering was more accurate for early cultivars than for late cultivars, suggesting that another factor (probably day‐length) also influenced flowering and had its greatest effect on the later maturing cultivars.
Effect of Plant Spacing on Phenological Development of Early and Midseason Corn Hybrids in a Semiarid Region1
Authors: Alessi J. , Power J. F. 
Published: July 2010

Within recent years, early maturing hybrids (Zea mays L.) (less than 70 days from seeding to silking) have become commercially available. This study at Mandan, N. Dak. was conducted to evaluate phenological differences between early and midseason maturing hybrids under semiarid conditions. Hybrids with 68 and 85‐day relative maturity were grown at plant populations of 20, 30, 40, 60, and 74 thousand plants/ha in 50 and 100‐cm spaced rows for 3 years. The 20, 40, and 74 thousand‐plant populations were sampled at intervals of 2 weeks in 1968 and 1969 and 3 weeks in 1970 to measure phenological development of leaf area and weights of stalks, leaves, and ears.Leaf area index during midseason was generally highest for the highest population and for the later maturing hybrids. Likewise dry weights of leaves and stalks, but not necessarily of ears, were usually highest for the 85‐day hybrid and for the higher populations. Particularly in drier years the 68‐day hybrid silked I to 2 weeks earlier than the 85‐day hybrid, providing more time before late summer drought or frost for grain filling. Treatments that resulted in less than about a 7‐week growing period after silking generally produced immature grain. Correlations between leaf area duration and total plant and grain yields were positive when water stress was not severe, but negative when water stress was severe. Higher populations fixed the greatest percentage of solar energy, as indicated by dry matter production. Row spacing generally had little or no effect upon the development and yield of the plant parts measured for either hybrid.Results indicate that early maturing hybrids are generally adapted to semiarid agriculture.
Anatomical Responses of ‘Merion’ Kentucky Bluegrass and ‘Pennlawn’ Red Fescue at Reduced Light Intensities1
Authors: Wilkinson J. F. , Beard J. B. 
Published: July 2010

The objectives were to characterize the anatomical responses of Kentucky bluegrass and red fescue to reduced light intensities. Kentucky bluegrass (Poa pratensis L. ‘Merion’) and red fescue (Festuca rubra L. ‘Pennlawn’) were grown in separate growth chambers at light intensities of 2.7, 10.8. and 43 klux. Light quality, soil moisture, and soil temperature were standardized among chambers. Anatomical studies were conducted on the youngest, fully expanded leaf blade.Merion displayed a decrease in cuticle thickness and vascular and support tissues under reduced light intensities, whereas Pennlawn did not. Stomata density of both species decreased under reduced light. Stomata pore length of both species did not vary with light intensity.The number of chloroplasts/cross sectional unit area decreased with reduced light intensity for both species. Merion had increased thylakoid and grana stack development within individual chloroplasts at reduced light intensities, whereas Pennlawn chloroplast ultrastructure remained unchanged.Shade adaptation of Pennlawn may be related to more developed cuticle, vascular, and support tissue and to chloroplast ultrastructure. Stomata and chloroplast density responses of the two species to reduced light intensity were similar and could not be associated with the ability of Pennlawn to provide a more desirable turf in the shade than Merion.
Performance of Genetically Comparable Diploid and Tetraploid Alfalfa: Agronomic and Physiological Parameters1
Authors: Dunbier M. W. , Eskew D. L. , Bingham E. T. , Schrader L. E. 
Published: July 2010

Diploid and tetraploid alfalfa (Medicago sativa L. sensu lato) populations were produced sexually utilizing numerically unreduced gametes and parthenogenetically developed haploids of 4x‐2x crosses. The advantage of the procedure over colchicine doubling is that genetically comparable populations, rather than individuals, at different ploidy levels can be studied. Additionally, both ploidy levels were in the same cytoplasm. Populations were grown in field plots to determine dry matter (DM) production and in a space‐planted nursery for analysis of the following characters; percentage total nonstructural carbohydrates (TNC), percentage total nitrogen (N), fresh weight/trifoliolate leaf, glucose‐6‐phosphate dehydrogenase activity (G6PDA), deoxyribonucleic acid (DNA) and water soluble protein concentration (WSP).As expected, concentrations of DNA, WSP, and N were basically the same in diploids (D) and tetraploids (T). T/D ratio was 2.10 for DM yield, 2.05 for fresh wt/trifoliolate, 2.09 for DNA/trifoliolate, and 1.78 for G6PDA/trifoliolate, indicating these characters were strongly influenced by ploidy. G6PDA/trifoliolate was higher in tetraploids but significantly higher in only one D‐T comparison, indicating that activity of this enzyme was influenced by factors in addition to ploidy. Phenotypic differences are thus demonstrated to be the result of a complex interaction between increasing gene dosage (polyploidy) and genetic regulation.