bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytology of Some Apomictic Paspalum Species1
Authors: Burson Byron L. 
Published: July 2010

Paspalum almum Chase had a chromosome number of 2n=4x=24. The number for P. brunneum Trin., P. coryphaeum Trin., P. haumanii Parodi, and P. rufum Nees. was 2n−4x−40; P. proliferum Arech. was 2n=6x−60. This is the first report of the chromosome number and cytological behavior for P. brunneum. The chromosome numbers found in P. coryphaeum, P. haumanii, P. rufum, and P. proliferum were different from any previously reported for these species. During metaphase I, the chromosomes in P. almum, P. brunneum, P. coryphaeum, P. haumanii, and P. rufum paired primarily as bivalents with occasional quadrivalents and a limited number of univalents were observed. P. almum, previously considered a diploid, had as many as five quadrivalents, which indicates it is an autotetraploid. Meiosis in P. proliferum was irregular with pairing primarily as 50 univalents and 5 bivalents at metaphase I and numerous laggards and micronuclei were observed.Megasporogenesis and embryo sac development of all six species showed aposporous apomixis followed by pseudogamy. This limits their use in an interspecific hybridization program. The possible origin of the new chromosome races, their relationships to other reported chromosome races of the same species, the role of apomixis in their evolution, and changes in the basic chromosome number of the genus were discussed.
Leaf Vein Frequency in Barley1
Authors: Hanson James C. , Rasmusson D. C. 
Published: July 2010

A survey of leaf vein frequency (LVF) in 210 varieties of barley (Hordeum vulgare L.) revealed approximately two‐fold differences (2.4 to 4.5 veins/nun) among varieties. Highly significant varietal differences were observed in four different environments, but the environment ✕ variety interactions were significant. Varieties differed significantly in number of major veins, number of minor veins, and in ratio of minor to major veins. In each variety, number of minor veins was more than double the number of major veins.The mean realized heritability for LVF in five populations in the F2 generation was 0.20 ± 0.04. In the F3 generations, mean realized heritability was 0.45 ± 0.07 for four populations. In both the F2 and F3 generations, the selection response was asymmetrical with more gain for selection for high than for low LVF. There was little evidence of association between LVF and specific leaf weight, but LVF was negatively associated with leaf length, leaf area, and leaf dry weight.
Heading Dates in Six Avena sativa L. × A. sterilis L. Crosses1
Authors: Lyrene P. M. , Shands H. L. 
Published: July 2010

AbstractHeading dates were studied in six Avena sativa L. ×A. sterilis L. crosses. The A. sterilis parents (CI 8077 and PI 295932) were later than the five A. sativa parents by 2 to 30 days. F1 plants and many F3 lines were earlier than the A. sativa parents. The earliness of interspecific progenies appeared to result from earliness factors inherited from A. sterilis parents; factors which were not expressed in A. sterilis due to a vernalization requirement. The vernalization requirement was absent in F1 progenies, apparently because of genes from A. sativa.Successful selection for early maturity in A. sativa × A. sterilis requires elimination of progeny with a vernal. ization requirement. Progeny tests of F3 lines indicated that earliness was easy to stabilize by selection.
Variability of In Vitro Dry Matter Digestion in Diallel and Polycross Progenies of Intermediate Wheatgrass1
Authors: Thaden Ronald T. , Ross James G. , Akyurek Ahmet 
Published: July 2010

AbstractVariation in height, seed set, and in vitro dry matter digestion (IVDMD) within a diallel and a polycross nursery of intermediate wheatgrass, Agropyron intermedium (Host) Beauv., were studied. Significant differences in IVDMD of whole tillers occurred among diallel crosses, but did not occur among polycrosses, indicating greater precision of measurement in the diallel. Differences among diallel crosses for plant fraction (flag leaf, peduncle, and spike) IVDMD were also significant. Digestibility of the peduncle contributed the greatest effect to whole tiller digestibility. It was concluded, however, that digestibility of the upper part of the plant could not be used as an indicator of whole tiller digestibility. Correlations of height, seed weight for 10 heads, and seed set with IVDMD were low. Significant general combining ability, specific combining ability, and reciprocal effects were found for each character. General combining ability estimates were highest in one parent for almost all characters investigated. Since additive genetic effects were predominant, the variability within the diallel cross population should allow success in selection of a superior cultivar for the characters studied
Groat Protein Percentage in Avena sativa × A. sterilis Crosses in Early Generation1
Authors: Lyrene P. M. , Shands H. L. 
Published: July 2010

AbstractA total of 600 F3 lines from six Arena sativa L. × A. sterilis L. crosses were screened for groat protein percentage in a test having two replications. Twelve lines having exceptionally high groat protein percentage, and nine with very low protein, were later compared with their A. sativa and A. sterilis parents in extensive progeny tests.Three of the high‐protein lines equaled their A. sterilis parents in groat protein percentage. One low‐protein line was significantly below its A. sativa parent in groat protein percentage; two others were not significantly different from the A. sativa parent. Of four A. sativa cultivars crossed with A. sterilis CI 8077, the one having highest groat protein percentage gave the highest‐protein progenies, while the one with lowest gave the lowestprotein progenies.It appears easy to recapture the high groat protein percentage of A. sterilis in A. sativa × A. sterills progenies. However, the most promising lines from these crosses were not those that were highest in protein, since the highest‐protein lines tended to have undesirable wildoat traits. The most promising lines were intermediate in groat protein percentage between their A. sativa and A. sterilis parents, and had the high grain yields and favorable agronomic qualities of A. sativa.
Diallel Analysis of Duration and Rate of Grain Filling of Seven Inbred Lines of Corn1
Authors: Cross H. Z. 
Published: July 2010

A diallel cross of seven inbred lines of corn (Zea mays L.) was examined for duration of the grain‐filling period, rate of fill, and associated agronomi characters to determine the practicability of selection for these traits. The length of the grain‐filling period and the rate of grain filling differed among hybrids and between years, but interactions between years and hybrids were not detected. Hybrids did not differ for duration of the lag phase of the grain‐filling period.The general combining ability effects for duration and rate of grain filling were larger than specific combining ability effects which snggested that simple selection techniques should be effective in changing these characters within the material studied. A phenotypic correlation of 0.81 was found between duration of the grain‐filling period and grain yield, while the correlation between rate of fill and grain yield was nonsignificant.Although the association between duration of the filling period and ear moisture content at harvest was high (r = 0.82), there was some evidence that it might be possible to shorten the vegetative period without sacrificing yield.
Gardener's Grid System and Plant Selection Efficiency in Cotton1
Authors: Verhalen Laval M. , Baker Jerry L. , McNew Ronald W. 
Published: July 2010

Gardner's grid system was investigated relative to plant selection efficiency within an upland cotton (Gossypium hirsutum L.) cultivar known to be genetically variable for fiber length. A relatively small area, planted to ‘Westburn,’ was arbitrarily subdivided into three equalsized grids prior to harvest. One hundred individual plant selections were made in each grid on the basis of boll type and apparent yield. Then, based on fiber length, the upper and lower 10% of the plants were selected within each grid and over the area as a whole. Progeny row performances of the selected plants were obtained for fiber length in two environments. Phenotypic variances, selection differentials, selection responses, and heritabilities under the two procedures (grids vs. no grids) were then compared at the 5 and 10% levels of selection intensity.In this experiment, the grid method reduced phenotypic variation by 22%; lowered selection differentials by 11 to 14%; produced 20 to 35% greater selection responses; and estimated “realized” (i.e., narrow‐sense) heritabilities 41 to 52% higher than did the identical selection procedure without grids.Based on the results of this and other experiments and on the logic underlying the method, use of grids should increase the effectiveness of plant selection regardless of crop, quantitative trait, or breeding method employed, provided there is genetic and environmental variability in the material. The method appears particularly useful when the breeder attempts to discriminate among small, inconsistent differences (i.e., when heritability is low). Use of the technique was considered for areas larger or smaller than those utilized herein, as well as for selection among progeny rows.
Percentage of Tissue Types in Tropical and Temperate Grass Leaf Blades and Degradation of Tissues by Rumen Microorganisms1
Authors: Akin Danny E. , Burdick Donald 
Published: July 2010

Tropical and temperate grasses were investigated for the amounts and the relative ease of degradation of tis. sue types in leaf blades to relate microanatomy to digestibility. Leaf blades of five tropical and six temperate grasses, grown in different locations but harvested at four weeks of summer regrowth, were examined by light microscopy for cross sectional percentages of total vascular tissue, lignified vascular tissue, phloem, epidermis, sclerenchyma, and mesophyll. Leaf blades of four of the tropical grasses and the six temperate species were evaluated for in vitro degradation of tissue types by tureen microorganisms using scanning electron microscopy.Bermudagrasses, Cynodon dactylon (L.) Pers. possessed about 36% total vascular tissue with 27% of the leaf blade section composed of parenchymal bundle sheaths; totals of vascular tissue for the other grasses were lower, ranging from 11.0% to 22.1%. The parenchymal bundle sheaths, which occupied > 50% of the area for total vascular tissue in tropical grasses but < 50% in all temperate species, were more rigid and usually digested at a slower rate in the tropical grasses. In all grasses, mesophyll and phloem were degraded before the other tissues but were degraded more rapidly in the temperate species. Leaf blades of tropical grasses had an average of 22 percentage units less of the easily digested tissue (mesophyll and phloem) and 25 percentage units more of the slowly digested tissues (epidermis and parenchymal bundle sheath) than temperate species. Except for the bermudagrasses, the percentages of lignified tissue were higher in temperate species. Differences in the ease of degradation were apparent between similar tissues of different grass types, species, and cultivars. Results indicated that leaf blade microanatomy and inherent characteristics of cell walls affect digestibility by rumen microorganisms.
Influence of Potassium Stress on Growth, Stomatal Behavior, and CO2 Assimilation in Corn1
Authors: Koch D. W. , Estes G. O. 
Published: July 2010

Crop potassium stress could be more easily diagnosed if the sequential plant responses to K deficiency were known. A greenhouse study was conducted to determine plant responses to K stress at several stages of development of corn (Zea mays L.). Potassium was supplied at 0.50 mM (Kl) and 3.0 mM (K2) of nutrient solution. Leaf stomatal resistance (rs) and CO2 uptake of the youngest fully expanded intact leaves were measured 30, 47, and 62 days after emergence. Potassium concentration of individual leaves of K‐adequate (K2) plants declined progressively with maturity; however, leaves of K‐stressed (Kl) plants declined to a much greater extent. High t, was associated with low K concentration of leaves at all three measurement dates. Stomatal frequency did not vary significantly with K treatment. The increase in rs did not result in reduced CO2 assimilation rates or plant dry matter weights at 30 or 47 days. At 62 days, r6 for leaves of K‐stressed plants was nearly 30% higher than for K‐adequate plants. Leaf area/plant was not significantly different; however, CO2 uptake was nearly 70% lower for K‐stressed plants at 62 days.There was a corresponding 30% reduction in dry matter accumulation for K‐stressed plants. High leaf K levels were associated with high specific leaf weights (SLW). Both high rs and low SLW in low‐K plants occurred before visible K deficiency was evident and at a concentration above the reported critical concentration. Potassium deficiency symptoms were not evident at any time during the experiment on recently expanded leaves of Kstressed plants. Increased rs and decreased SLW were early indicators of developing K stress and may be useful in diagnosis of K deficiency
Automated Hydrolysis of Nonreducing Sugars and Fructosans from Plant Tissue1
Authors: Wolf D. D. , Ellmore T. L. 
Published: July 2010

Analytical procedures for chemical analysis of carbohydrates by measuring reducing power before and after hydrolysis, have been automated once the carbohydrates have been removed from the plant tissue. Sugars and fructosans were removed from forage tissue by hot water treatment. Reducing sugars in an aliquot were assayed by automated procedures without acid hydrolysis. Total water‐soluble carbohydrates were measured with automated acid hydrolysis of the same aliquot. Nonreducing carbohydrates were calculated as the difference between total water‐soluble carbohydrates and reducing sugars. Sucrose and fructosan were completely hydrolyzed during the 2 min. exposure to 0.2 N acid at 95 C that were the conditions in automated hydrolysis. However, starch, if present in the water solution, was not broken down by the automated hydrolysis procedure due to low acid concentration and short duration of exposure to heat.Automated procedures increased lab efficiency, reduced routine errors, and eliminated filtration, pipetting, and manual dilution often required by most procedures.
Heterosis and Combining Ability Estimates for Air Pollution Damage, Primarily Ozone, in Maryland Tobacco1
Authors: Huang Tsun‐shih R. , Aycock M. K. , Mulchi C. L. 
Published: July 2010

Estimates of heterosis and general and specific combining ability for air pollution damage, primarily ozone, on Maryland tobacco (Nicotiana tabacum L.) were obtained under greenhouse and field conditions. A diallel set of crosses (excluding reciprocals) among seven Maryland tobacco cultivars was used for the greenhouse fumigation‐chamber study. Tobacco plants, aged 10 to 12 weeks, were exposed to ozone at 50 pphm for 4 hours in a fumigation chamber. Significant differences in ozone susceptibility were observed among the seven parents and their 21 F1 hybrids. The heterotic response of the hybrids was toward greater ozone susceptibility. Diallel analysis of variance of the F1 hybrid generation indicated a large amount of variance due to general combining ability and a small amount due to specific combining ability.An additional cultivar was added to the diallel set of crosses for the field study and was grown at three locations. Air pollution data (commonly referred to as weather fleck under field conditions) for the eight parents and 28 F1 hybrids were similar to the data obtained in the greenhouse. However, heterosis for weather fleck was small and not significant in the combined analysis over locations. Variability for general combining ability was significant for the three locations and in the combined analysis over locations, and specific combining ability was significant at one location only. These estimates suggest a predominance of additive genetic variance in the population for weather fleck.
Protein Composition in Developing Groats of an Avena sativa. L. Cultivar and an A. sativa ✕ Avena sterilis L. Selection1
Authors: Ohm H. W. , Peterson David M. 
Published: July 2010

‘Noble’, CI9194, an Avena sativa L. cultivar with a medium percentage of groat protein, and Purdue 65256C4‐38, a selection from a cross of A. sativa ✕ Avena sterilis L. with a high percentage of groat protein, were grown in the field in 1972 and 1973 at Lafayette, Ind. Primary groats in the top half of panicles were harvested at 2 or 3‐day intervals from anthesis until several days after maturity. Groat dry weight, percentage of protein, and protein solubility fractions were measured.Increase in dry weight ceased at about 22 days after flowering, whereas percentage of protein increased slightly until about 28 days after flowering. The high‐protein cultivar maintained a higher level of protein throughout groat development. Globulins and glutelins comprised the major portion of protein in both cultivars, but levels of these two fractions were higher in the highprotein cultivar. Albumins and prolamins increased during maturation of the groats, but at maturity, each comprised less than 20% of the total protein.
Absorption, Distribution, and Form of Ca in Relation to Ca Deficiency (Tip Burn) of Sugarbeets1
Authors: Mostafa M. A. E. , Ulrich A. 
Published: July 2010

Sugarbeet plants (Beta vulgaris L.) were grown in the greenhouse in nutrient solutions containing 0.33 and 5.0 meq Ca/liter. Carrier‐free 45Ca was added at transplanting to nutrient solutions of a set of sugarbeet pots and the rest were left untreated. Two weeks later, the 45Catreated pots were harvested and another set was treated with 45Ca. This process was repeated for three more harvests with addition of 45Ca at 2, 4, and 6 weeks and harvesting, respectively, at 4, 6, and 8 weeks after transplanting. All in all, there were four 45Ca additions and four harvests. At each harvest, the various parts of the plant were assayed for 45Ca that was associated with Ca soluble hi 80% alcohol, as chloride and nitrate, in water as salts of organic acids, in 1 N NaCI as pectate, in 2% CH3COOH as di‐ and triphosphate, in 0.6 N HCI as oxalate and insoluble residue.Symptoms of Ca deficiency were associated with an incomplete uptake of Ca from the nutrient solution, a high rate of Ca consumption by the storage roots, and a failure to translocate sufficient Ca to the tops to support rapid young leaf growth, but were not associated with the formation of an insoluble Ca compound(s). Since 45Ca was detected in various forms in all parts of Cadeficient sugarbeets, the pathway for Ca remained functional even as the symptoms increased in severity.Calcium phosphate, rather than Ca oxalate, was at a high concentration hi all parts of the Ca‐deficient and Ca‐sufficient plant, except Ca oxalate exceeded Ca phosphate in the mature and old blades of the Ca‐sufficient plant. If Ca immobility inhibits the transport of Ca from older to younger parts, then the formation of Ca phosphate could be a limiting factor under deficiency and not under sufficiency conditions.
Nutritional Stress and Ethylene Evolution by Young Cotton Bolls1
Authors: Guinn Gene 
Published: July 2010

Previous results have shown that a nutritional stress increases the rate of young boll abscission from cotton (Gossypium hirsutum L.) plants. Tests were conducted to determine whether a nutritional stress affects the rate of ethylene evolution by 4‐day‐old bolls. Fruiting cotton plants were subjected to conditions that should decrease photosynthesis (dim light, short days), increase respiration (long warm nights), or change the demand for products of photosynthesis (partial boll removal, changing boll load during a growing season).As little as one day of dim light caused a measurable increase in ethylene. Partial boll removal slightly decreased the effects of subsequent exposure to dim light. Bolls from plants exposed to three consecutive long warm nights produced more ethylene than bolls from control plants. Rate of ethylene evolution by bolls of field‐grown plants increased almost eightfold from June 25, when the boll load was light, to July 30, when the boll load was heavy.Sugar analyses indicated significant negative correlations between sugar content of bolls and their rate of ethylene evolution.The results indicate that a nutritional stress increased rates of ethylene evolution by young cotton bolls. This additional ethylene is probably a causal factor in the increased rates of boll abscission that occur when cotton plants are subjected to conditions that promote a nutrltional stress.
Performance of Cytoplasmic Male‐Sterile Cotton Under Natural Crossing in New Mexico1
Authors: Rosales Franklin E. , Davis D. D. 
Published: July 2010

Cytoplasmic male‐sterile (Gossypium harknessii Brandg. ✕ Gossypium hirsutum6 L.) lines versus similar malefertile lines of cotton were evaluated for yield and lint percentage under conditions of natural pollination for 2 years at Las Cruces, N.M. Two locations distinguished by their relative distance from a honeybee (Apis mellifera L.) apiary were used each year.Bee populations appeared to be a major factor in these experiments. Fewer bees were apparently necessary for good pollination of the male‐sterile lines than was previously reported. Eight of the twelve comparisons for yield between steriles and fertiles were statistically significant. The male‐sterile lines produced less seed cotton and lint each year in the field more distant from the bee hives. Near the apiary, the steriles produced significantly more seed cotton and seed than the fertiles. No significant differences were detected for the interactions of sterility ✕ pollinators or of sterility ✕ nectaries for any of the agronomic traits studied, although there were some indications that there was a partial honey bee preference for nectaried plants.Breeding programs which include improved Cytoplasmic male‐sterile strains and adequate populations of honey bees may provide the means for commercial production of hybrids.