bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breeding Alfalfa for Resistance to the Stem Nematode, Ditylenchus dipsaci1
Authors: Sherwood R. T. , Dudley J. W. , Busbice T. H. , Hanson C. H. 
Published: July 2010

An experimental synthetic, combining agronomic characteristics of Flemish alfalfa with stem nematode resistance equivalent to that found in ‘Lahontan’, was developed largely by backcrossing. Selections were made in a naturally infested field. Certain selected plants were further evaluated by inoculating their S1 progeny under controlled conditions in a laboratory.A second resistant synthetic was developed by recurrent selection in the susceptible variety ‘Cherokee’. Laboratory tests of seedling reaction were the basis for all selections; in each of two successive cycles, mass selection was followed by S1 progeny testing of selected plants.The procedure followed in developing resistance in the second synthetic appeared to be more efficient than the one used in the first. Results from laboratory tests agreed well with those from field tests, but laboratory evaluation was found to be more reliable and economical for determining resistance.
Response of Soybeans to Tiba (2,3,5‐Triiodobenzoic Acid)and High Fertility Levels
Authors: Hicks D. R. , Pendleton J. W. , Scott W. O. 
Published: July 2010

Glycine max (L.) Merr., ‘Wayne’, was used to study the effects of the antiauxin TIBA (2,3,5‐triiodobenzoic acid) at high levels of fertility in field trials at Urbana, Illinois.The following responses were observed for TIBA treated plants. Leaf area was reduced 20%. Plant height was decreased 33% due to shorter internode lengths. The nitrogen content of leaves and protein content of the seed were decreased; the oil content was unaffected. Pod set increased while the number of seeds per pod decreased. The number of seeds per plant increased, but reduction in seed size caused the total seed yield to remain approximately the same. Standability was improved by TIBA.Large broadcast applications of fertilizers on this highly productive Corn Belt soil did not increase soybean yields.There was also no interaction found for fertility and TIBA.
Inheritance of Quality and Quantity of Seed‐Oil in Safflower (Carthamus tinctorius L.)1
Authors: Yermanos D. M. , Hemstreet S. , Garber M. J. 
Published: July 2010

A safflower introduction from India and the variety ‘N‐10’ were crossed reciprocally to produce F1, F2, F3 and backcrossed generations. The same 2 lines were grafted reciprocally. Seed samples from these materials were analyzed for oil content and composition. Seed‐oil of N‐10 has high iodine value while that of the other line has low iodine value.It was found that the iodine value of safflower oil: (a) is determined by the genotype of the seed and not by that of the sporophyte on which the seed develops; (b) is not influenced by maternal effects; (c) is controlled by a single locus with one recessive allele producing low iodine value and the other, partially dominant, producing high iodine value; and (d) has a very high heritability.The oil content of the seed is controlled by several genes without any apparent dominance gene action. Significant positive correlations were found: between (a) iodine value and palmitic, stearic and linoleic acid; and (b) between oil content and palmitic acid, linoleic acid, and iodine value. Significant negative correlations were found between oleic acid and palmitic acid, linoleic acid, iodine value and oil content.Oil composition was not affected by maternal effects, flower color, spinines
Performance of Inbred Lines in Hybrid Combination During the Transfer of a Single Gene (ae) Locus in Maize (Zea mays L.)1
Authors: Duclos Z. M. , Patterson F. L. , Kramer H. H. 
Published: July 2010

The effects of the gene ae and possible linked factors were studied with regard to yield during the transfer of ae to the four inbreds of the double cross hybrid U.S. 13. The effects of the gene and its linkage block in the inbreds were studied in backcross test during three generations of backcrossing and selfing. The effects of the gene and its linkage block in hybrids were studied in single cross tests following various generations of back crossing to the four inbreds.Expected lengths of linkage block segments around the ae locus held heterozygous for the different generations were calculated. From these the percent heterozygosity was calculated for ae and normal phenotypes. Observed and expected yields were compared with the t‐test. The expected yield was calculated by equating the difference between the mean of the inbreds and the single cross to 100% heterozygosity. Expected yield was based on percent hetorozygosity.The ae gene and not genes linked with it appeared to have a strong adverse effect on yield. Evidence from ae kernels and normal kernels from the same ear indicated that the effect of gene ae was on kernel size, supporting existing evidence that ae blocks the formation of branch chain polysaccharides without a corresponding increase in straight chain polysaccharides.
Effect of Temperature, Light, and Nitrogen on Growth and Metabolism of ‘Cohansey’ Bentgrass (Agrotis palustris Huds.)1
Authors: Schmidt R. E. , Blaser R. E. 
Published: July 2010

Bentgrass growth, carbohydrate reserves, and NP were influenced by temperatures. Evidently, after carbohydrates were utilized to a certain degree at high temperatures, growth was reduced below the yield of bentgrass grown at lower temperatures. Carbohydrate reserves apparently reflect the energy balance between photosynthesis and respiration and growth. This was verified by stimulated top growth but decreased carbohydrates when bentgrass was grown under warm days and cool nights.Although bentgrass fertilized liberally with N had high photosynthetic rates, much of the stored energy was reduced and root development was less than with low N. Shade caused a reduction in photosynthesis which decreased the carbohydrate content and growth.Data suggest that seasonal temperature must be considered in timing N fertilization for best bentgrass development.
Monosomic Analysis of Fertility‐Restoration in Common Wheat (Triticum aestivum L.)1
Authors: Robertson L. D. , Curtis B. C. 
Published: July 2010

Monosomic analysis of the restoration genes in Triticum timopheevi Χ Marquis3, a hexaploid fertility‐restorer with T. timopheevi cytoplasm known to possess two major dominant genes Rf1Rf1Rf2Rf2, revealed that chromosome 1A carries one of the major genes. Inconclusive data prevented identification of the other chromosome carrying a major gene. Chromosome 3A was not studied.Chromosomes 1B, 2A, 3D, 6A, and 6B of ‘Chinese Spring’ appear to carry modifier genes which prevent normal expression of restoration when absent, even though Rf1 and Rf2 genes are present.
Heterosis and Combining Ability in Intraspecific and Interspecific Crosses of Cotton1
Authors: Marani A. 
Published: July 2010

Trials were conducted in 1961 and 1962 on seven and eight varieties, respectively, of G. hirsutum L. and G. barbadense L. and all possible reciprocal crosses between them. The average magnitude of heterosis for lint yield was 24.5% and 21.6% in the intraspecific crosses of G. Oirsutum L. and G. barbadense L., respectively, and 72.8% in the interspecific crosses. Heterosis for lint yield was associated in all cases with heterosis for yield of seedcottou and in many cases also for the number of bolls per m2. Heterosis for boll‐weight was found only in G. hirsutum L. intraspecific crosses where it was associated with heterosis for seed‐index, lint‐index, and number of seeds per boll. The interspecific crosses had a low lintpercent because heterosis for seed‐index was much more pronounced than heterosis for lint‐index in these crosses.Effects of general combining ability in the interspecific crosses, which were more pronounced than effects of specific combining ability, corresponded to the performance of the parental varieties themselves. If heterosis in interspecific crosses is to be used to breed F1 hybrids, the selection of parental varieties should be made on the basis of their own performance for those traits that have shown consistent and significant effects of general combining ability.
Boll Retention in Relation to Leaf and Boll Development in Cotton (Gossypium hirsutum L.)1
Authors: Johnson R. E. , Addicott F. T. 
Published: July 2010

The effect of leaf area and gibberellic acid (GA) boll retention was studied on cotton plants growing in nutrient culture. Leaf area was reduced to approximately half the control by two methods of leaf clipping, and two concentrations of GA were applied to all flowers.In control plants, the ratio of leaves to retained bolls was initially high. It declined to approximately three at midseason, and thereafter remained constant to the end of the fruiting period. After adjustments for differences in leaf size, ratios for partially defoliated plants were similar to those of the control. Percent boll retention paralleled leaf‐boll ratios.Seed cotton yield and percent retention were significantly reduced in the partially defoliated treatments; however, no differences were found when seed cotton yield was expressed as a function of maximumle af area developed. There were no differences between the GA treatments and control for any of the characters measured. That retention was not increased by treating all the flowers contrasts with results obtained when only a few flowers or young bolls were treated.The number of seeds per retained boll for all treatments was low initially, increasing to a maximum at the time of greatest shedding. This may indicate that a high seed complement is required for a boll to be retained when competition for assimilate occurs.The results are interpreted as supporting the view that boll retention depends on the presence of a sufficient number of developing seeds to mobilize the assimilates required for contiuued growth, and upon the availability of assimilates as governed by the vegetative‐reproductive status of the plant.
Heterosis and Combining Ability in Barley1
Authors: Upadhyaya B. R. , Rasmusson D. C. 
Published: July 2010

Eight parental varieties of barley and the 28 possible F1 and F1 populations were evaluated in spaced plantings in two environments. The traits studied were yield, kernel weight, kernels per head, heads per plant, and height.The average heterosis values of F1's based on midparent means for yield, kernel weight, kernels per head, heads per plant, and height were 21.5, 5.9, 7.1, 7.6, and 3.2%, respectively. When the F1's were compared to the high parent, the average heterosis for yield was 9.1%. The average inbreeding depression for yield in the F2 generation was 26.1%General and specific combining ability variances were obtained from the F1 data, using Griffing's experimental method 4, model II. A substantial amount of additive and nonadditive genetic variance for yield was indicated. Most of the genetic variance for kernel weight, heads per plant, kernels per head, and height was additive.The yield of the best hybrid exceeded the highest yielding parental varieties, Liberty and Traill, by 22 and 38%, respectively. A hybrid advantage of this degree combined with evidence of considerable nonadditive genetic variance for yield indicates the desirability of additional research on hybrid barley. The results reported indicated that performance per se can be used as a basis for initial screening in evaluating potential parental varieties for use in a hybrid breeding program.
Internode Length in Height Mutants of the Sorghum Variety Wheatland1
Authors: Brooks James S. 
Published: July 2010

Four lines were established in the sorghum variety ‘Wheatland,’ each homozygous for a separate mutation from dw2 to Dw3. A replicated planting of these mutants and three normal Wheatland plants was made to study the effect of the Bw3 allele on the length of the various internodes among otherwise isogenic lines.Internodes one and five were most effected and internode three least effected by the Dw3 allele.
Inheritance of Soybean Seed Quality I. Heritability of Laboratory Germination and Field Emergence1
Authors: Green D. E. , Pinnell E. L. 
Published: July 2010

Individual plants of parental, F1 and F2 populations, and F3 progenies of soybeans were evaluated for seed quality as measured by seedling emergence percentage in the field and by six determinations made in a standard laboratory test. The laboratory determinations were percent normal seedlings plus hard seed, normal seedlings at 5 days, total normal seedlings, abnormal seedlings, decayed or dead seed, and hard seed. Five parental populations consisted of two commercial varieties, Chippewa and Harosoy 63, and three Japanese strains, Wasedaizu No. 1 (PI261469), Matsuura (PI200499), and Kimusume (PI229336). Six F1 and six segregating (F2 and F3) populations were produced from crosses of each Japanese strain as female parent with each of the commercial varieties.Estimates of broad sense heritability for the field emergence and laboratory germination characters were generally low positive or negative values because of high environmental variances in parents and F1's. Narrow sense heritabilities ranged from 3 to 29% for field emergence, from 2 to 60% for the three determinations of normal seedlings in laboratory germination tests, and from 31 to 71% for hard seed. Fa population means for the seed quality characters were usually equal to or higher than the mid‐parent values. In each cross 10 to 20% of the F3 families exceeded the high parent for field emergence. Thus, improvement in this character from selection would seem easy, in spite of the low calculated heritabilities, if selection pressure is applied on F3 to Fn families rather than on single plants and if some replication is used in producing family seed for testing.Percentages of normal seedlings plus hard seed, normal seedlings at 5 days, and total normal seedlings were about equally well correlated with percentages of normal seedlings in field emergence tests. Abnormal seedling and hard seed percentage in laboratory tests were not as closely associated with field emergence.
Inheritance of Soybean Seed Quality II. Heritability of Visual Ratings of Soybean Seed Quality1
Authors: Green D. E. , Pinnell E. L. 
Published: July 2010

Seed from the parental, F1, and segregating (F2 and F3) soybean populations were evaluated for quality by visual ratings for wrinkled seedcoats, shriveled cotyledons, green cotyledon color, an arithmetic average of the three previous ratings, and an overall visual rating. These ratings were on a 1 to 5 scale, with 5 being the most extreme expression of the character.The variance among single plants in the commercial varieties for the visual ratings was generally high in relation to the variance in the Japanese strains and in the F1 populations. However, the variance in the F2 populations was generally large in comparison to the arithmetic mean of the variances within the respective parental and F1 populations resulting in broad sense heritability estimates ranging from 41 to 63% for wrinkled seedcoats, 14 to 57% for shriveled cotyledons, 52 to 82% for green cotyledons, 41 to 71% for the average visual rating, and 22 to 64% for the overall visual rating. Narrow sense heritability estimates for the visual ratings ranged from 6 to 30% for wrinkled seedcoats, 10 to 38% for shriveled cotyledons, O to 29% for green cotyledons, 1 to 28% for the average visual rating, and 7 to 28% for the overall visual rating.Low visual ratings for wrinkled seedcoats, shriveled cotyledons, green cotyledons, low average visual ratings, and low overall visual ratings were generally associated with high percentages of normal seedlings in field emergence tests. This was especially true in the F3 and ‘Chippewa’ parental populations in which more variation existed in each of the characters being tested.The average visual rating was somewhat more consistent in predicting relative field emergence than any of the ratings of separate seed characters. However, the overall visual rating appeared to be about equal in this respect. Considering both precision of measurement and time utilization, an overall visual rating followed by field emergence testing may be the most efficient means of evaluating segregating populations of soybeans for seed quality.
Forage Density Gauging with Sr90 for Estimating Green Forage Yield in situ1
Authors: Barta A. L. , Teare I. D. 
Published: July 2010

An accurate and reliable technique for estimating green forage yield in situ has been developed which utilizes beta particle attenuation by plant material.This technique involves the attenuation of beta particles from a strontium‐90 source by the vegetative mass of a forage stand. By measuring the intensity of the transmitted beta beam through different forage stands, a yield calibration curve was made which relates green forage yield to counts per minute. It was also found that the slope of the yield calibration curve was independent of the three crops tested as well as moisture content, thereby allowing a single yield calibration curve to be used for all forages.A field instrument was constructed to measure the practical value of density gauging to estimate green forage yield.Regression analysis of the experimental field data showed that this method accounted for 86% of the variation in yield and affirmed its usefulness in pasture research.
Photorespiration and Glycolate Metabolism in Tobacco Leaves1
Authors: Moss Dale N. 
Published: July 2010

The stimulating effect of light on the evolution of CO2 from tobacco leaves into CO2‐free air was suppressed by inhibition of glycolate oxidase with α‐hydroxy‐2‐pyridinemethanesulfonic acid. The inhibitor strongly inhibited photosynthesis at both 25 and 35 C. The CO2 compensation concentration increased indefinitely for leaves treated with inhibitor. Glycolate accumulation in leaves treated with inhibitor was strongly dependent on inhibitor concentration and light intensity and was linear with time up to one hour. Temperature for growth or during the experiments had little effect on accumulation.The possible internal CO2 from the oxidation of glycolate calculated on the basis of glycolate accumulation under optimal conditions indicates that photorespiration from glycolate as a substrate may be at least 2‐fold dark respiration. Although the possible rate of respiration from glycolate metabolism was large, it was not sufficient to account for the differences in photosynthesis between maize and tobacco on the assumption that this difference was due to internal recycling of CO2 in tobacco.
Cumulative Gene Effects and the Nature of Heterosis in Maize Crosses Involving Genetically Diverse Races1
Authors: Castro M. G. , Gardner C. O. , Lonnquist J. H. 
Published: July 2010

Five open‐pollinated varieties each representative of a different racial group and 35 other populations developed from them (the five varieties selfed, 10 F1 crosses, and the random mated and selfed progenies of the F1 crosses), were grown in three environments in Mexico. Data were taken on grain yield, days to flower, plant height and number of ears per 10 plants. The phenotypic means of the 40 populations for each trait were analysed separately by analysis of variance technique, and the variance among populations was subdivided according to the model and analysis I outlined by Gardner and Eberhart (1966).In the case of yield, the greatest contributing factor to genetic variation was intravariety dominance effects (52.4% of the total). Additive gene effects contributed most to variation among means in days to flower (87.9%), plant height (79.3%) and ear number (60.9%). Average heterosis in the crosses explained 5.1% of the total variation in yield means whereas varietal and specific heterosis effects accounted for only a minor portion of the variation and were nonsignificant statistically. In the other traits, “the variation accounted for by heterosis effects was, in all cases, nonsignificant.Estimates of the gene effects were used to compute predicted means of the entries in the experiment, the advanced generations of crosses of three and four races and more precise estimates of heterosis. The highest yielding predicted crosses in advanced generations are suggested as basic genetic material to be used in a mass selection program prior to initiating any breeding procedure involving inbreeding.The data obtained are considered to fit the genetic model used. No evidence was found to indicate that epistasis contributes to heterosis in the traits studied even though genetically diverse varieties of maize were crossed. The possible presence of undetectable types of epistasis and the stability of the estimated gene effects in different environments are discussed.
Heterosis and F2 Performance in Intraspecific Crosses Among Varieties of Gossypium hirsutum L. and of G. barbadense L.1
Authors: Marani A. 
Published: July 2010

Three trials, conducted in 1964 and 1965 in Israel, included a set of four varieties of G. hirsutum L. and their intraspecific crosses in all combinations in the F1 and F2 generations, and a similar set of four G. barbadense L. varieties and their F1 and F2 intraspecific crosses. Heterosis for lint yield was 15 to 24% and 21 to 28% in G. hirsutum L. and G. barbadense L. intraspecific F1 crosses, respectively. This was always associated with heterosis for yield of seed‐cotton and for the number of bolls produced. Heterosis for boll‐weight was found in G. hirsutum L., but was not always shown by G. barbadense L. Heterosis for boll number was associated with a higher percentage of boll retention in G. hirsutum L. and with more flower production in G. barbadense L.F2 deviations from the average of mid‐parent and F1 performances were relatively small for lint yield, indicating that although some epistatic effects may be operative for this trait, additive and dominance genetic effects are more important. In G. hirsutum L. significant F2 deviations were found for lint‐index and lint‐percent, and in some cases also for seed‐index. In G. barbadense L. a significant F2 deviation was found only for flower number in one experiment.
Heterosis and Inheritance of Quantitative Characters in Interspecific Crosses of Cotton1
Authors: Marani A. 
Published: July 2010

Performance of the F1, F2 and backcross generations of nine interspecific crosses, between each of three varieties of Gossypium hirsutum L. (‘Acala 4‐42’, ‘Empire W,’ and ‘Coker 100A’) and each of three varieties of G. barbadense L. (‘Karnak,’ ‘Malaki,’ and ‘Giza 7’), in comparison with the parental varieties, was evaluated in three field trials in 1964 and 1965. Heterosis (F1 performance above mean of parents) was between 52% and 73% for lint yield and was associated with heterosis for boll number, flower number, and percentage of boll retention. Boll weight of F1 hybrids was intermediate and their lint percent and number of seeds per boll were lower than the parental mean. Heterosis was also significant for seed index, lint index and plant height.F2 deviation (F2 performance below mean of F1 and midparent) and backcross deviations (BC performance below mean of F1 and recurrent parent) were significant for almost all of the characters examined. Lint yield of the F2 was much lower than that of either parent, whereas lint yield of backcrosses was similar to that of the recurrent parents. Heterosis was caused by dominance effects only (no epistasis) for seed index and in one trial for final plant height. Heterosis for yield of seed cotton, yield of lint, boll number, flower number, percentage of boll retention, lint index and plant height at flowering was caused by dominance in the presence of epistasis. Intermediate F1 performance (no heterosis), found for boll weight and for maturity, was caused by the estimates of dominance and additive ✕ additive epistasis parameters being of nearly equal magnitudes. The negative heterosis found for lint percent and number of seeds per boll was caused by the additive ✕ additive epistasis being larger than the dominance effects.