bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heritability and Combining Ability for Gossypol Content in Six Lines of Upland Cotton1
Authors: Yang H. C. , Davis Dick D. 
Published: July 2010

Six lines of upland cotton (Gossypium hirsutum L.), selected for different levels of gossypol and other terpenoids in flower buds, were intercrossed in all combinations, including reciprocals. Parents and F1 hybrids were grown in a complete diallel set with three replications m one environment. Analysis of variance of gossypol level, using the methods of Grilling, revealed a large and highly significant component for general combining ability, and a small nonsignificant component for specific combining ability. There was also a very small, but significant, estimate for reciprocal effects. We concluded that gossypol in flower buds is inherited in an additive manner (94% narrow sense heritability) and should thus be readily selectable.Analysis of the same materials using Hayman's technique confirms the highly significant and predominant additivity of inheritance, but also suggests that dominance cannot be completely ruled out as a source of significant variation.
Development of Zero‐Alpha Hop Genotypes1
Authors: Haunold Alfred , Likens S. T. , Nickerson G. B. 
Published: July 2010

Hop (Humulus lupulus L.) cultivars normally contain both alpha and beta acids in varying amounts. Alpha acids are the principal flavoring substances for malt beverages. The closely related beta acids are of less importance for brewing because of their low solubility in cold wort. The progeny of a cross between two low‐alpha acid hop genotypes showed significant transgressive segregation for alpha and beta acid content. One male and eight female siblings contained no detectable alpha acids in their lupulin glands. A highly significant correlation was found between quality analyses on a cone basis and on a lupulin basis.Zero‐alpha hops will be useful for studying the inheritance of beta acids independently of alpha acid content. Such hops may also allow brewing chemists to measure the contribution of beta acids to beer flavor.
Effects of Irrigation History on Responses of Cotton to Subsequent Water Stress1
Authors: Cutler J. M. , Rains D. W. 
Published: July 2010

Experiments were designed to test the hypothesis that the internal water relations and stomatal and growth responses to water status of cotton plants (Gossypium hirsutum, ‘Acala SJ 2’) can be modified by prior tissue water deficits. Different levels of stress conditioning were achieved by varying irrigation frequency during a pretreatment period.Growth was limited by water stress under conditions of low and moderate irrigation frequency during the pretreatment period. During the final drought period, tissue water desorption characteristics, stomatal closure thresholds, and (inferentially) turgor sensitivity were different in stress‐conditioned plants from those in plants not subjected to prior stress. Analysis of the relationships of water potential to relative water content suggested that osmotic adjustment might play a role in the reduced sensitivity of hardened plants. The altered behaviors of prestressed plants were in the right direction to explain differences observed between the responses of controlled. environment and field‐grown plants and suggest that stress‐conditioned plants are less sensitive to tissue water deficits.
Heterosis and Combining Ability of Seed Protein, Yield and Yield Components in Long Bean1
Authors: Mak C. , Yap T. C. 
Published: July 2010

Seven cultivars of long bean (Vigna sesquipedalis Fruw.) were crossed in diallel; the parents and F1's were evaluated in the field in 1973. Out of 42 hybrids, only three had seed protein contents significantly greater than the higher parent values. A majority of the hybrids yielded more than the higher parent. The amount of heterosis ranged from 40.7% below to 63.2% above the higher parent values. Of these, however, only two were statistically significant. Among the yield components, pods per plant showed the greatest amount of heterosis. Heterosis in seeds per pod, pod length, and seed weight were relatively low.Both general combining ability (GCA) and specific combining ability (SCA) were important for all traits measured except pod yield where only GCA was significant. Good combiners for pod yield were poor combiners for seed protein content and the SCA effects for yield depended mainly on the SCA values of the yield components.
Application of Restricted Selection Indexes for Improvement of Economic Value in Oats1
Authors: Rosielle A. A. , Eagles H. A. , Frey K. J. 
Published: July 2010

The dollar return from growing oats Avena sativa L. in the midwestern United States is a function of both grain and straw yields. Restricted selection indexes were used to determine the effect of restricting heading date and height on selection potential for economic value among F9‐derived lines from a bulk populatiou of oats. Four unrestricted and eight restricted selection methods were considered. The eight restricted methods comprised two economic values, optimum and base methods, and two degrees of restriction on heading date and height. Expected and actual advances were calculated.Direct selection for increased economic value saved lines with late heading dates and tall plants. Holding heading date and height to the means of the unselected population removed correlated responses in heading date and height, but decreased advance from selection for economic value. More severe restrictions on heading date and height reduced the advance in economic value to near 0.0. Restrictions on heading date and height had a more severe effect on straw yield than on grain yield.Optimum restricted selection indexes, in which grain and straw yields were entered as separate traits, were only slightly more efficient than base restricted indexes in which the two traits were combined into the single character economic value.Changing the relative economic values of grain and straw had little effect on expected or actual advances. Restricted selection for economic value was effective with measurements on plant weight, heading date, and height only; i.e., without measuring grain yield.Expected and actual advances for heading date and height agreed closely for all methods. Expected advances for grain yield, straw yield, and economic value were overestimates of actual advances with unrestricted methods, but agreed closely with actual advances for restricted methods.
Protein Body Size and Distribution and Protein Matrix Morphology in Various Endosperm Mutants of Zea mays L.1
Authors: Baenziger P. S. , Glover D. V. 
Published: July 2010

Maize (Zea mays, L.) protein body size and distribution and matrix morphology were studied to determine their relationship with endosperm lysine content and kernel density and vitreousness. Thirteen near‐isogenic (Bc 6) endosperm mutant genotypes, their double mutants with opaque‐2, and the normal Oh43 inbred were studied. Two endosperm mutants, sugary‐2 (su2) and waxy (wx), and their double mutant with o2 each near‐isogenlc (Bc 6) inbreds B37, C103, and W64A and their normal and opaque‐2 counterparts were also studied. Mature kernels of these genotypes were thin sectioned, destarched, and studied using interference‐contrast light microscopy.Protein bodies were observed and measured in amylose. extender (ae), dull (du), floury‐1 (fl1), soft starch (h), su2 and wx endosperm of Oh43 and in the normal counterpart. Protein body size was significantly different among genotypes and decreased going into the center of the kernel from the aleurone layer.No protein bodies were visible in o2, floury‐2 (fl2), sugary‐1 (su1), shrunken‐1 (shl), shrunken‐2 (sh2), brittle‐1 (btl), and brittle‐2 (bt2). The endosperm mutants with high lysine levels had no visible protein bodies while the mutants with intermediate lysine levels had fewer and generally smaller protein bodies than did the mutants with the lower lysine levels.Opaque‐2 and the double mutants with o2 did not have visible protein bodies and the matrix was generally thinner than in the single mutants. Sugary‐2 opaque‐2 had a thicker, more extensive matrix than observed in o2 endosperm.Protein bodies were visible in the su2 and wx isogenic conversions of Oh43, B37, C103, and W64A and their normal counterparts. Differences among inbreds, genotypes, and the interaction of inbred × genotypes were highly significant. No protein bodies were visible in o2 and the double mutants with o2. The data suggest that protein matrix may be involved in the expression of kernel density and vitreousness. The matrix of vitreous su2o2 kernels resembled the matrix of vitreous sue kernels and not that of o2 kernels.
Studies on Nitrate Reducing System in Developing Wheat Ears1
Authors: Nair T. V. R. , Abrol Y. P. 
Published: July 2010

Developing wheat (Triticum aestivum L.) ears (grains and glumes) are sites of nitrate reduction. Nitrate reduced by the developing ear was incorporated into grain protein. In a field experiment, when no N was supplied, nitrate reductase (NR) activity (µmoles NO2‐/g.f.w./hour) in the glumes and grains was not significantly different from that in the flag leaf blade. Application of N significantly enhanced the NR activity of the flag leaf blade but not that of glumes and grains.Total NR activity (NR activity/g.f.w./hour ✕ fresh weight) of the developing ears equalled that of the leaf blades on the main shoot at low N (0 & 90 kg/ha) levels. At high N (180 kg/ha) level the total NR of the leaf blades was significantly higher than that of the developing ears.In detached culm experiments, flag leaf blade as well as glumes responded to nitrate in the medium even when the detached culms were obtained from plants grown at high N (I80 kg/ha) level. This suggested that under field conditions the enzyme, NR, was operating at sub‐optimal levels. The magnitude of response of glumes was lower than that of the flag leaf blade suggesting preferential flow of nitrate towards the leaf blade or translocational barrier to nitrate movement to the ear.NR activity in the grains was neither enhanced by soil N application nor by additional supply of nitrate to the detached culms.
Variability and Selection Advance for Photosynthesis in Iowa Stiff Stalk Synthetic Maize Population1
Authors: Crosbie T. M. , Mock J. J. , Pearce R. B. 
Published: July 2010

Photosynthesis is a primary trait influencing yield potential, and it should be improved in a yield‐potential selection program. Information concerning the genotypic variability and inheritance of photosynthetic efficiency in maize (Zea mays L.) must be obtained before a yield‐potential selection program is initiated.We used CO2‐exchange rate (CER) of sections from excised leaves to estimate photosynthetic efficiency of 64 random inbred fines of maize derived from Iowa Stiff Stalk Synthetic (BSSS). Our study was conducted for years at one location. Measurements of CER taken during vegetative growth (CER 1) and during grain filling (CER 2) were used to estimate genotypic variances and heritabilities and to calculate selection advances for these two stages of plant development. We also evaluated the possibility of using specific leaf weight and leaf thickness as index traits for CER selection.Results showed that estimates of additive variance were 1.7 and 4.9 times larger than estimates of genotype ✕ environment variance at CER 1 and CER 2, respectively. Narrow‐sense heritabilities were 0.58 for CER l and 0.80 for CER 2, and realized heritability values were 0.72 (CER 1) and 0.66 (CER 2). A high genotypic correlation between CER at CER 1 and CER 2 indicated selection at either developmental stage would produce nearly identical results. Actual selection advances (15% selection intensity) represented increases of 14 and 22% above population means for CER 1 and CER 2, respectively. Our data suggested that measurement of two replications of four plants/plot grown in two environments would provide most efficient selection advance for inbreds. We concluded that selection for improved CER in BSSS would be possible and that selection must be for CER per se.
Effects of Leaf Aging Upon Stomatal Resistance in Bean Plants1
Authors: Davis S. D. , van Bavel C. H. M. , McCree K. J. 
Published: July 2010

The effect of leaf age on leaf resistance to gaseous diffusion was separated from three factors inherently related to leaf age: (a) progressive shading of lower leaves, (b) plant development, and (c) changes in stomatal size and density. Bush beans (Phaseolus vulgaris L., ‘Contender’) were grown and studied in an environmental chamber under constant conditions. Measurements of leaf resistance, light level, and stomatal density were made throughout the life of the plant (10 to 60 days from plant emergence). It was found that in a fully expanded leaf, exposed to constant light, the diffusive resistance of the whole leaf increased continuously with age until leaf abscission. The same was found true for leaves that were continuously shaded at 15% of the full light level (1,150 μ;einsteins m‐2 s‐l), but the resistances were higher. The rate of change in leaf resistance with time varied among the leaves within a plant, but the differences were eliminated when the time scale was expressed as the fractional lifespan of each leaf.Further, the effects of correlated factors such as shading, stage of plant development, and stomatal densities were negligible; and the leaf age effect occurred not only during the latter stages of senescence, when the leaf was becoming chlorotic or necrotic, but as a continuous process, beginning at leaf maturity and continuing until leaf abscission.
Genotypic Differences in Nitrate Absorption and Partitioning of N Among Plant Parts in Maize1
Authors: Chevalier Peggy , Schrader L. E. 
Published: July 2010

The objectives of this study were to compare corn (Zea mays L.) inbreds and their F1 hybrids with respect to pattern of nitrate (NO3−) uptake during the growth period and partitioning of absorbed N among plant parts. A four‐parent (‘W64A’, ‘WI82E’, ‘A632’, ‘Oh43’), half‐diallel of corn was used. Disappearance of NO3− from solution culture was monitored from 10 days after emergence until 20 days after silking. Plants were then harvested and the distribution of total N, NO3−, and reduced N (RN) among leaf blades, leaf sheaths, stems, ears, and roots was determined.Significant differences in NO3− uptake per plant were found among the 10 genotypes, but there was no relationship between NO3− removed by F1 hybrids and that removed by their inbred parents. Genotypic differences in dry weight, NO3− and RN per plant, and NO3− and RN còncentrations were found in all plant parts. Inbreds W64A and WI82E were especially high in NO3− and RN. Dry weight and NO3− in all plant parts, and RN in all plant parts except ears, were usually greater in hybrids than in inbreds. In general, stem NO3− concentration of the F1 approximated the mid‐parent mean. Concentration of NO3− in other plant parts of F1 hybrids was not related to that of their parents. No relationship between parents and progeny in RN concentration was found in any plant part.In this study, genetic variation in NO3− uptake and partitioning of absorbed N was demonstrated. This variation suggests the potential for genetic improvement of NO3− uptake and N utilization by corn.
Leaf Photosynthetic Characteristics of Determinate Soybean Cultivars1
Authors: Bhagsari A. S. , Ashley D. A. , Brown R. H. , Boerma H. R. 
Published: July 2010

Apparent photosynthesis (AP), photorespiration (Pr), transpiration (T), specific leaf weight (SLW), and diffusion resistances were measured to characterize these physiological parameters in 16 determinate soybean [Glycine max (L.) Merr.] cultivars, four each in maturity groups V through VIII. Data were obtained on 12 to 16‐day‐old terminal leaflets attached to plants grown in a greenhouse.In three separate sets of measurements AP rates of the 16 cultivars ranged from 23 to 37 mg CO2 dm−2 hour−1 and differences among cultivars were found in each of the three measurements. Significant differences among cultivars were also observed in Pr, T, and SLW. Mesophyll diffusion resistance (rm) calculated from AP and T data also differed among cultivars. Pr not only increased as AP increased but also accounted for a higher percentage of photosynthesis in cultivars with higher Pr. AP rate was positively correlated with T and negatively correlated with laminar plus stomatal (ra+ra) diffusion resistance and with rm. The correlation of AP with SLW was significant in only one of three measurements. The determinate cultivars examined in this study display for most physiological parameters a similar range in cultivar performance as published reports for indeterminate cultivars.
Genetic Variability for Chemical Composition of Alfalfa. II. Yield and Traits Associated with Digestibility1
Authors: Hill R. R. , Barnes R. F. 
Published: July 2010

Quantitative genetic parameters were estimated for first harvest yield, acid detergent fiber (ADF), acid detergent lignin, in vitro dry matter disappearance (IVDMD), and protein in ‘Saranac’ and ‘MSA‐C4’ alfalfa (Medicago sativa L.). Neutral detergent fiber (NDF) and in vitro cell wall digestibility (IVCWD) were determined in Saranac. Genotypic, phenotypic, and environmental correlations among each of the characters and with concentrations of 11 mineral elements were computed for Saranac. All estimates were obtained from analysis of a series of four, five‐parent diallel crosses and their parents in each cultivar.Relatively large estimates of heritability were obtained for lignin (43.8%) and protein (64.4%) in Saranac, extremely low estimates were obtained for IVDMD in both cultivars (7.9% for Saranac and 6.1% for MSA‐C4). Heritabilities for the remaining characters wcre intermediate (22.0 to 33.8%). In breeding for improved nutritive value of alfalfa, selection for greater protein content or reduced ADF, NDF, or lignin content would be recommended over selection for greater IVDMD.Estimates of genotypic, phenotypic, and environmental correlations indicated that: (1) Yield was not strongly correlated with any of the quality parameters; (2) ADF, NDF, and lignin were positively correlated with each other and negatively correlated with IVDMD and protein; and (3) IVDMD and IVCWD were positively correlated. Althongh seldom significant, most of the correlations for mineral concentration with yield, ADF, NDF, and lignin in Saranac were negative. Protein content was positively correlated with P concentration; ADF was negatively correlated with Ca, Mg, and Fe concentrations; and lignin was negatively correlated with K concentration.
Seasonal and Fertility‐Related Changes in Cottonseed Protein Quantity and Quality1
Authors: Leffler H. R. , Elmore C. D. , Hesketh J. D. 
Published: July 2010

Utilization of seed protein from cotton (Gossypium hirsutum L.) as an ingredient of food products for nonruminant animals may provide producers with a salable seed commodity in addition to oil and meal. It was therefore important to establish the effects that environmental conditions migbt have on cottonseed protein quantity and quality (amino acid composition).Cotton was grown at two levels of N fertility at each of two locations in Mississippi. At each location, N concentration was higher in cottonseed produced in high‐N N plots than in seed produced in low‐N plots. For the single harvest at Starkville, enhancement of seed N by fertilization was 1.18%. For the first five harvests at Stoneville, enhancement of seed N ranged from 0.85 to 1.10%. A stratified harvest at Stoneville enabled the identification of seasonal influences on seed size and chemical composition. Both seed size and seed N concentration decreased with later developmental periods. Seed oil concentration, however, increased with later developmental periods.Both N fertility and seasonal patterns caused slight, but statistically significant, changes in the amino acid composition of cottonseed protein. Generally, as seed N increased, the concentrations of lysine, threonine, glycine, and alanine in the seed protein decreased; concentrations of arginine and glutamic acid increased. Because both N fertilization and seasonal factors can influence cottonseed protein quantity and amino acid composition, comparisons of these factors should be made only among environmentally similar samples.
Studies of Ethephon as a Possible Selective Male Gametocide on Tef1
Authors: Berhe Tareke , Miller Dwane G. 
Published: July 2010

The gametocidal effect of ethephon (2‐chloroethyl phosphonic acid) was studied in two varieties of tef [Eragrostts tef (Zucc.) Trotter] ‘DZ‐01‐99’ and ‘DZ‐01‐186’. Foliar applications of 600, 900, and 1,200 ppm were applied three times during heading. The primary objective was to investigate if ethe~phon could be used as a substitute for hand emasculation in tef, therefore alleviating the floral sensitivity problem associated with hand manipulation of florets. All rates of ethephone reduced seed set. The lowest seed set reduction (33%) was obtained from one 600 ppm application and the highest (74%) from three 1,200 ppm applications. Reduction in seed set was not altered by artificial pollination of florets after chemical treatment. Phytotoxicity due to ethephon spray was minimal. The gametocidal effect of ethephon on male gametogenesis was first noted at the free microspore stage. Development of microspores was arrested. When pollen grains developed, they were malformed and stained poorly. In some cases, the pollen grains or anthers aborted completely.Histological studies of ethephon‐treated florets revealed that embryo sac development was not affected up to the time of fertilization. However, soon after the megagametophyte matured into the eight‐nucleate stage and at about the time of fertilization, ovary and ovular tissue in sterelized florets underwent premature desiccation and collapse. It is assumed that this response led to female sterility since ethephon‐sterilized florets yielded no seed. Therefore, ethephon seems unsuitable for use in tel breeding. However, since conventional emasculation and pollination techniques also have not yielded hybrid seed, the induced sterility cannot be ascribed entirely to chemical application.
Peroxidase Activity in Roots and Leaves of Soybeans1
Authors: Dunleavy J. M. , Urs N. V. Ramaraje 
Published: July 2010

Peroxidase activity in leaves and roots of 24 soybean (Glycine max (L.) Merr.) cultivars was determined 63, 83, and 109 days after planting. Peroxidase activity in soybean leaves increased with each sampling period. The mean activity of all cultivars at 83 and 109 days was 1.8 and 5.4 times greater, respectively, than at 63 days after planting. Peroxidase activity in leaves of most cultivars varied considerably during the season.At 63, 83, and 109 days after planting, peroxidase activity of roots was 17, 7, and 4 times greater, respectively, than in leaves. Activity in soybean roots, as in the leaves, varied considerably with the sampling periods. The mean peroxidase activity in roots was relatively high at 63 days, decreased at 83 days, and increased to 1.2 times the initial activity at 109 days. There was a much greater range between highest and lowest peroxidase activities in both leaves and roots of soybean cultivars at 63 days than at other sampling periods. When peroxidase activity in roots and leaves of five soybean cultivars each in maturity groups II, III, and IV were compared at 63, 83, and 109 days after planting, there was no relation between peroxidase activity and plant maturity.