bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clonal and Progeny Evaluations in Two Populations of Tall Fescue (Festuca arundinacea Schreb.)1
Authors: Thomas J. R. , Frakes R. V. 
Published: July 2010

Clonal evaluation and five progeny testing methods (S1, open‐pollinated, polycross, single‐cross, and F2) were compared for three traits in two populations of tall fescue for 3 years. The three traits were plant height, seed yield, and seed weight. The progeny tests were compared by selecting the best parental clones on the basis of each of the six tests using Duncan's multiple range test, then observing which methods led to the selection of the same parental clones.The results indicated: (1) there was generally good agreement among years for the traits studied; (2) use of clonal evaluation with 1 year's data might result in loss of equal clones, but seldom would obviously superior clones be discarded; (3) clonal evaluation and Sj and single‐cross progeny tests generally gave similar results, while the open‐pollinated, polycross, and F2 progeny tests were generally the least useful for detecting differences among the clones; and (4) clonal evaluation would be quite useful in evaluating large numbers of clones for synthetic varieties, but single‐crosses should be made and tested to determine the best two clone combinations.
Rotenoid Content and Growth Characteristics of Tephrosia vogelii as Affected by Latitude and Within‐Row Spacing1
Authors: Barnes D. K. , Freyre R. H. , Higgins J. J. , Martin J. A. 
Published: July 2010

Four varieties of the tropical legume, Tephrosia vogelii, a source of the natural insecticide rotenone, were tested for one season at three locations to investigate the effect of latitude and plant spacings on several growth characteristics and on total rotenoid accumulation in the leaves. Planting locations included Mayaguez, Puerto Rico, 18° N; Clemson, S. C., 34° N; and Glenn Dale, Md., 38° N. Planting distances included 1 m between rows and three spacing distances (15 to 23 cm, 30 to 38 cm, and 53 to 61 cm) between plants within the row.Rotenoid (rotenone and related compounds) accumulation patterns varied among varieties, but the relative rating of varieties for percentage rotenoid content per unit of dry weight was not influenced by planting distance or latitude. Plant growth characteristics such as plant height, leaf‐stem ratio, and total yield of stems and leaves were significantly influenced by variety, within‐row spacing, and location. Since these growth characteristics are associated with total rotenoid production per hectare, within‐row plant spacing which provides 30,000 to 37,000 plants per hectare is suggested as the optimum planting pattern for T. vogelii. Maximum yields of total rotenoids obtained at Clemson, S. C., Glenn Dale, Md., and Mayaguez, P. R., were 82, 104, and 185 kg/ha, respectively.
Inheritance of Relative Phosphorus Accumulation in Corn (Zea mays L.)1
Authors: Barber W. D. , Thomas W. I. , Baker D. E. 
Published: July 2010

Analysis of corn leaf tissue has revealed significant differences among corn inbreds and corn hybrids for the concentrations of various chemical elements, including phosphorus. An investigation was initiated in an attempt to assess the consistency and nature of the apparent genetic control of phosphorus accumulation in corn.Experiments designed to study the inheritance of differences in phosphorus concentration, measure accumulation differences in seedlings, and assess the effects of variations in soil phosphorus on accumulation differences were conducted in 1962 and 1963. Data from these experiments verify the existence of genetically controlled phosphorus accumulation variations and indicate that at least two genetic factors are involved with the possibility of dominance for the lower phosphorus level in at least one of these factors. There were no apparent relationships of phosphorus accumulation with the accumulation of other elements, including K, Ca, Mg, Mn, Fe, Cu, B, Al, Sr, and Zn. No noticeable effects of soil phosphorus level upon the expression of accumulation differences was revealed. This study also failed to indicate any relationship of leaf phosphorus concentration to grain yield.Genotypes which accusnulated highly significant different amounts of phosphorus in mature leaf tissue were little or no different as seedlings when grown in pots.
Variation and Covariation in a High Oil Population of Corn (Zea mays L.) and Their Implications in Selection1
Authors: ElRouby Mohamed M. , Penny L. H. 
Published: July 2010

Sixty‐four half‐sib families, each containing four full‐sib families, were grown in replicated trials in five environments. Data were collected for silking date, plant and ear heights, kernel size, lodging percentage, shelling percentage, oil percentage, yield of grain, and yield of oil. Estimates of additive and dominance variances were calculated for each trait, and these variance estimates were used to predict the genetic gain from different selection methods. Phenotypic and additive genetic correlations among traits were calculated.All estimates of additive genetic variance were significantly greater than zero. None of the estimates of dominance variance was significant except for yield of grain in one environment. Mass selection appeared to be the most effective method of selection for higher oil percentage in this population, but recurrent selection for general combining ability would be the most effective method for yield of grain and yield of oil. The only traits significantly correlated with oil percentage were silking date and yield of oil. A selection index for improving yield of oil appeared to have little advantage over selection for yield of oil alone.
Barley Yellow Dwarf Studies in Wheat (Triticum aestivum L.). I. Yield and Quality of Hard Red Winter Wheat Infected With Barley Yellow Dwarf Virus1
Authors: Fitzgerald Paul J. , Stoner Warren N. 
Published: July 2010

Barley yellow dwarf virus infection caused highly significant yield losses in three varieties of hard red winter wheat. Yield reductions resulted from a reduced number of heads per foot of row, fewer kernels per head, and reduced kernel weight.Fall‐infection resulted in greater yield losses than spring‐infection. Differential winterkill due to fall‐infection did not appear to account for yield differences.Height of the plants and number of heads per foot of row also showed highly significant reductions caused by the disease, but differences due to time of infection were not significant.Milling and baking quality were somewhat adversely affected by the BYD disease, but differences between healthy and diseased samples were generally small and inconsistent among the varieties. Samples from diseased plants in all varieties were poorer or just equal to the samples from healthy plants for test weight, 1000‐kernel weight, and kernel size. Flour protein percentage was slightly higher in grain samples from diseased plants in all varieties.
Effects of Temperature and Photoperiod on Metabolic Changes in Alfalfa in Relation to Cold Hardiness1
Authors: Shih S. C. , Jung G. A. , Shelton D. C. 
Published: July 2010

Investigations were conducted to evaluate the effects of temperature and photoperiod on metabolic changes during development and maintenance of cold hardiness of two alfalfa (Medicago sativa L.) varieties varying widely in inherent cold hardiness. Cold temperatures appeared to be of primary importance for development and maintenance of cold hardiness, whereas both temperature and pbotoperiod played important roles in the metabolic processes.The content of protein, RNA, or DNA was positively associated with development and maintenance of cold hardiness. The content of protein or RNA located in microsomes was more closely associated with cold hardiness than was the content of these constituents located in other subcellular fractions. Tissue pH was higher at the peaks of cold hardiness than at other times. The hardy ‘Vernal’ variety contained more protein, RNA, or DNA than the nonhardy ‘Arizona Common’ variety during development and maintenance of cold hardiness.
Induction of Polyploidy in Linum Species1
Authors: Yermanos D. M. , Gill K. S. 
Published: July 2010

Colchicine was evaluated at six concentrations (0.0125, 0.025, 0.05, 0.1, 0.2, and 0.4% in water) for the induction of polyploidy. Three Linum species, L. usitatissimum (var. ‘Imperial’ and ‘Abyssinian yellow’), L. angustiSolium, and L. narbonense, were treated at different stages of development. The most effective treatment was 0.1% colchicine for 6 hours on germinating seedlings. Effectiveness of the treatments depended on species, concentration, duration of application, and duration Χ concentration interaction. Polyploids could be identified 3 weeks after treatment by their increased stomata size and later by their larger flower, seed, and pollen grain size.Meiotic behavior was studied in auto‐tetraploids of L. usitatissimum, L. angustifolium, L. africanum, L. altaicure, L. grandifiorum, L. maritimum~ L. narbonense, L. rigidum, and L. tenuifolium. A high frequency of quadrivalents was formed by all species at meiosis involving 33 to 71% of the chromosome complement. Chlasmata frequency in tetraploids was lower than in diploids. Pollen viability and number of seeds per capsule were lower in all auto‐tetraploids, but seed and capsule size were larger. Oil content and degree of unsaturation were lower in tetraploids, while moisture content of the seed was higher.
Influence of Stem Diameter on Oviposition Preference of the Alfalfa Weevil and Its Importance in Breeding for Resistance1
Authors: Norwood B. L. , Barnes D. K. , VanDenburgh R. S. , Hanson C. H. , Blickenstaff C. C. 
Published: July 2010

This investigation consisted of two laboratory experiments which were designed to study the influence of stem size on oviposition preference of the alfalfa weevil, and the effect of that interrelationship on selection for resistant plants with large stems. F1, F2, and S1 progenies were studied.Alfalfa strains and single crosses differed significantly for number of eggs per stem and stem diameter. In the two experiments the mean number of eggs per stem and stem diameter were correlated (r = .91**, 15 df and r .71**, 26 df). Plants with small stem diameters tended to have less oviposition. However, in progenies of several plants oviposition preference was not entirely dependent on stem diameter.Available evidence suggested that a breeding program, based on selecting plants with low oviposition preference and large stem diameter, might result in significant progress in developing an agronomically acceptable variety with resistance to oviposition. HOwever, this nonpreference type of resistance would have to be evaluated under field conditions before its potential economic value could be ascertained.
Male Gametophyte of Zea mays L. I. Some Factors Influencing Fertilization1
Authors: Walden D. B. 
Published: July 2010

Geneticists and breeders have standard procudures of pollen and ear shoot preparation for controlled pollination of corn, but meager data are available to quantify comparisons of techniques. Three experiments were conducted in which limited, controlled numbers of pollen grains were applied at various times to prepared and unprepared ear shoots of a single‐cross hybrid, Oh 51At ✕ B8. Genetic constitution of pollen and ovule parents permitted detection of contaminant kernel.Cutting to a brush the silks on ear shoots resulted in significantly more seed set than using uncut or freshly cut ear shoots. Hour of pollination and the time required for pollen tube establishment in the distal 3 cm of silk were tested, Five to 10 hours were required for 3 cm of pollen tube growth; pollinations made before 2 PM required 5 to 7 hours, while pollinations made after 4 PM until 10 PM required successively longer periods. The longevity of corn pollen was estimated. Viable pollen grains were recovered after 292 hours of storage at + 2 C. Pollen may be shipped around the world in a viable condition. It was concluded that the techniques used by most corn workers provided optimal opportunity for seed set.
Studies of the Physiological Basis for Yields Differences. III. Genetic Variation in Photosynthetic Efficiency of Phaseolus vulgaris L.1
Authors: Izhar S. , Wallace D. H. 
Published: July 2010

Photosynthetic efficiency was measured by infrared analysis of net CO2 exchange (NCE), using single attached leaves of intact greenhouse grown plants. The leaves were sampled as they approached full expansion or shortly thereafter. One or two measurements of the rate of NCE by primary or trifoliate leaves from several plants were used to estimate the photosynthetic efficiency of a variety. The mean from five observations, usually five different leaves, was used to estimate the genetically controlled potential in photosynthetic efficiency of individual plants from segregating progenies.‘Michelite‐62’ significantly exceeded the closely related variety ‘Monroe’ by about 9% and ‘Perry Marrow,’ ‘Steuben,’ and 'Red Kidney' by 22%, 35%, and 31%, respectively. Light response curves for Michelite‐62 and Red Kidney were similar, but the net CO2 uptake of Michelite‐62 exceeded that of Red Kidney by about 20% at all light intensities above the compensation point. Light saturations of about 37.7 and 70.0 kilolux, respectively, were obtained with winter and summer grown plants, but the absolute rate of net CO2 uptake was about the same for the two intensities. Below the compensation point, Michelite‐62 evolved more CO2 than Red Kidney. It was determined that the basis for the varietal difference in NCE resides in the reactions of photosynthesis that proceed in the dark rather than those that are light dependent.The photosynthetic efficiencies of Red Kidney and Michelite‐62, their F1 and F2 progenies, and a backcross to Red Kidney suggested that the genetic mechanism controlling the varietal difference in net CO2 exchange rate is quantitative, that there may be relatively few genes involved, and that there is some dominance for the low photosynthetic efficiency of Red Kidney.
Performance of a Spring Wheat Hybrid, F2, F3, and Parent Varieties at Five Population Levels1
Authors: Briggle L. W. , Cox E. L. , Hayes R. M. 
Published: July 2010

The F1 and parents involved in a spring wheat cross (‘Lemhi 53’ Χ ‘HenryΧ) were grown at five population levels under irrigation for 3 years at Aberdeen, Idaho. The F2 was grown in the same experiment for 2 years and the F3 for 1 year.Little heterosis was evident in plant height.Heterosis was expressed by the hybrid in grain yield. Performance of the F1 compared to the higher parent was remarkably consistent. The F1 produced 19.5% more grain (over all population levels) than the higher yielding parent in 1963; 19.2% more in 1964; and 16.5% more in 1965. In general, performance of the F2 was lower than that of the F1, and performance of the F3 was slightly lower than that of the F2.The hybrid produced more spikes per plant than either parent, but no heterosis was expressed in number of kernels per spike. Limited heterosis was evident in kernel size.F1 and parent plants were slightly taller when grown at the higher plant densities.Population level had a pronounced effect on yield of grain. An apparent maximum yield was reached by hybrid plants when spaced 1.27 cm (½ inch) apart within rows which were spaced 30.5 cm (1 ft) apart. This represents a seeding rate of approximately 1.9 hectoliters/ha (6‐½ pecks per acre). Yield was not significantly reduced, however, in 2 of the 3 years, when plants were spaced 2.54 cm (1 inch) apart. This is equivalent to a seeding rate of approximately .9 hectoliter/ha (3 ¼ pecks per acre). Cost of hybrid seed could force a producer to reduce his seeding rate to near the latter level. More yield trials of a similar nature are needed before a positive recommendation can be made. Yield of parents was likewise influenced by plant density but was more erratic from year to year than yield of the F1.Plants grown at low population levels produced more spikes and more kernels per spike than those grown at high levels. Seed size was influenced little by plant density, although there was a trend toward smaller seed at the high population levels.
Effect of Potassium on the Content of Amino Acids in Alfalfa and Orchardgrass Grown With NO−3 and NH+4 Nitrogen in Nutrient Solution Culture1
Authors: Macleod L. B. , Suzuki Michio 
Published: July 2010

Alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) were grown on nutrient solutions with N at 50 and 250 ppm having 25 or 75% of the N at each concentration supplied as NH+4 and with K at 10, 50, and 250 ppm. Tissue was harvested at the late bud and pre‐boot stages respectively, immediately frozen, and later analyzed for free and conjugated amino acids using a Beckman/Spinco amino acid analyzer.NH+4 nitrogen was more readily incorporated into the free amino acid pool than the NO‐3 form. Aspartic acid plus asparagine was the predominant amino acid in both plant species, and the ratio of this fraction to glutamic acid plus glutamine reflected the effect of nutrition on nitrogen metabolism. In general this ratio decreased with an increasing K/N ratio in the nutrient solution, and the minimum ratio was found when the K/N ratio was 5/1. At this K/N ratio the alcohol‐insoluble N fraction of total N was maximum. The highest amino acid content was found when the K/N ratio was 1/5.
Isogenic Analysis of Strontium‐89 Accumulation in Barley1
Authors: Rasmusson D. C. , Kleese R. A. 
Published: July 2010

The effect of short segments of chromosomes on Sr‐89 accumulation in barley, Hordeum vulgate L., was studied by comparing Sr‐89 accumulation in pairs of isogenic lines. The members of each isogenic pair differed by segments of chromosome estimated to be less than 6 recombination units in length.Six of the 11 chremosome segments studied influenced Sr‐89 accumulation in grain, stems, or leaves of mature plants or in shoots of seedling plants. In three of the segments the marker gene that served to identify the segment appeared to effect the differential accumulation of Sr‐89. The three genes were those that control hoods vs. awns, long vs. short awn, and naked vs. covered caryopsis. In addition, the chromosome segments identified by the genes controlling two vs. six rows of kernels, black vs. white lemma and pericarp, and purple vs. nonpurple lemma and pericarp had a significant effect on Sr‐89 accumulation.The study leads to the conclusion that the genetic basis for differences in Sr‐89 accumulation involves a number of genes and is highly dependent on the genetic stocks involved.
Inheritance of Two Female‐Sterile Characters in Dwarf‐Internode Castor (Ricinus communis L.)1
Authors: Brigham Raymond D. 
Published: July 2010

Two female‐sterile characters in dwarf‐internode castor were investigated and the inheritance of each appeared to be controlled hy a single recessive gene. The symbols fs1 and fs2 are proposed. In fs1, all pistillate flowers failed to open, and pollen‐fertile staminate flowers tended to remain closed or only partially opened. Perianth segments in pistillate flowers were tightly fused. The epidermal cells of the perianth of flowers of both sexes were abnormally enlarged, resulting in a rough, pebble‐like surface. Normal‐monoecious plants had smooth epidermal layers. The perianths of the pistillate and staminate flowers were 25 and 40% thicker, respectively, in fs1 than in the variety ‘Hale.’In fs2, pistillate and staminate flowers appeared normal, but capsules failed to enlarge after stigmas were fully exserted. The stigmas dried within a few days, followed by gradual drying of the capsules. Pollen was fertile and stained easily. Cause of the fs2 type female sterility was not apparent in this study.
Resistance of Alfalfa Varieties to the Potato Leafhopper: Seedling Survival and Field Damage After Infestation1
Authors: Webster James A. , Sorensen E. L. , Painter Reginald H. 
Published: July 2010

Twenty‐eight varieties and four experimental populations of Medicago sativa L., were tested in the seedling stage for resistance to the potato leafhopper, Empoasca fabae (Harris). The extremely winter‐hardy varieties, ‘Rhizoma,’ ‘Rambler,’ ‘Teton,’ exhibited high seedling survival. In contrast, the nonhardy varieties, ‘African,’ ‘Hairy Peruvian,’ ‘Indian,’ ‘Moapa,’ and ‘Sonora,’ were highly susceptible. The reaction of the Flemish types, ‘Alfa,’ ‘DuPuits,’ and ‘Glacier,’ was similar and intermediate among varieties tested. The Turkistan‐derived variety, ‘Lahontan,’ was highly susceptible. ‘Cherokee’ and the populations MSA‐11 and MSB‐11, which were developed for resistance to yellowing in the field from susceptible source material by recurrent selection, were resistant in greenhouse seedling tests. Experimental synthetics, KS 13 and N. S. 16, rated high for resistance in field and seedling tests.Field yellowing scores were negatively correlated with seedlings survival in growth chamber tests (r= −0.607*). Repeatability of seedling resistance as determined by survival was demonstrated by a highly significant interannual correlation coefficient (+0.702***) for the unifoliolate growth stage.
Growth of Birdsfoot and Alfalfa. III Changes in Carbohydrates Reserves and Growth Analysis Under Field Conditions1
Authors: Nelson C. J. , Smith Dale 
Published: July 2010

The amount of total available carbohydrates (TAC) in the roots of 'Empire' birdsfoot trefoil were lower and the changes were less pronounced than in the roots of 'Vernal' alfalfa at similar growth stages. The difference on a weight basis was much greater than by percentage. Starch, sucrose, glucose, and fructose were the components of the TAC of both species. Relationships among the fractions of the TAC were similar for both species throughout the growing season.Alfalfa had a higher crop growth rate (CGR) than trefoil except at late stages of maturity when growth of trefoil continued by active upper axillary branching. CGR of alfalfa was higher than trefoil because there was a greater leaf area and it developed faster. Alfalfa was more efficient in the conversion of radiant energy into dry matter because it had a higher leaf area index than trefoil at comparable net assimilation rates. This advantage over trefoil was attributed to a higher photosynthetic rate for alfalfa leaves and to a better light distribution in the taller alfalfa canopy.
Effect of a Generation of Inbreeding on Genetic Variation in Corn (Zea mays L.) as Related to Recurrent Selection Procedures1
Authors: Horner E.S. 
Published: July 2010

Response from selection for combining ability is proportional to the genetic variance among test crosses in each cycle. Theoretically, this variance can be increased appreciably by a generation of inbreeding in the population under selection prior to initiation of a new cycle. for a single locus with two alleles, crossing S1 rather than S0 plants with a tester is expected to increase variance among test crosses within intercross progenies (of selected S1 lines from the previous cycle) by 100%, and over the entire population by 50%. Sib‐pollination within intercross progenies would be only one‐half as effective as selfing in this respect. Random mating of the population for one generation would have no effect on test cross variance so far as individual loci are concerned.Experimental data for grain yield were in good agreement with the expected results based on genetic theory. In populations produced by intercrossing S1 lines, a generation of sib‐pollination within intercross progenies increased the esimate of test cross variance from 0.046 to 0.141 where an increase of 50% was expected. Where S2 lines had been intercrossed, a generation of inbreeding increased test cross variance from zero to 0.172. It was concluded that a generation of inbreeding prior to initiation of a new cycle would be a worthwhile step in recurrent selection programs.