bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Variability in Acid Detergent Fiber, Crude Protein, and Their Association with Some Morphological Characters in Smooth Bromegrass1
Authors: Tan Wai‐Koon , Tan Geok‐Yong , Walton P. D. 
Published: July 2010

A seven × seven half diallel of smooth bromegrass Bromus inermis Leyss., including parental clones, was evaluated for acid detergent fiber (ADF) and crude protein (CP) of whole forage at two harvests and of leafblade, leaf‐sheath, and stem sampled before the first harvest. The objectives were to assess the genetic variability for the quality components, and to examine the associations between the two quality components and some morphological characters.The relative magnitude of the variances due to general and specific combining ability indicated that most of the genetic variance appeared to be nonadditive. Neither ADF nor CP showed significant combining ability at the second harvest. The narrow‐sense heritability estimates were quite high for ADF of the leaf‐blade (46%) but were very low for ADF and CP of whole forages at both harvests (3 to 8%) and for ADF of other plant fractions (0 to 19%). The nature of the genetic variances for ADF and CP suggested that more complicated breeding methods would be necessary for quality improvement.Acid detergent fiber of the leaf‐sheath and stem was closely associated with whole forage ADF (r = 0.70 and 0.84). High correlations were obtained between harvests for both ADF and CP (r = 0.71 and 0.61). ADF increased while CP decreased with increasing plant height and forage yield. Vein frequency was positively correlated with ADF of whole forage (r = 0.41) and leaf‐sheath (r = 0.51). Most phenotypic characters showed little correlation with either ADF or CP at the first harvest.
Phenotype, Fiber Composition, and in vitro Dry Matter Disappearance of Chemically Induced Brown Midrib (bmr) Mutants of Sorghum1
Authors: Porter K. S. , Axtell J. D. , Lechtenberg V. L. , Colenbrander V. F. 
Published: July 2010

Chemically induced brown midrib (bmr) mutants sorghum (Sorghum bicolor (L.) Moench) were characterized with regard to phenotype, fiber composition, and in vitro dry matter disappearance (IVDMD). The recessive bmr genes produced brown pigmentation in the leaf midrib and stem of mature plants. Pigmentation varied among mutants in intensity, time of appearance, and degree of fading as plants matured.Stem and leaf samples of mutant and normal plants were analyzed in the laboratory to determine percent cell wall constituents (CWC), acid detergent fiber, (ADF), cellulose, hemicellulose, permanganate lignin (PL), vitro dry matter, and in vitro cell wall constituent disappearance (IVDMD and IVCWCD). Ten of the 13 mutants had significantly less stem lignin than the normal counterparts. Reductions in lignin ranged from 5 to 51% in stems and from 5 to 25% in leaves. In the case of other fiber components, only occasional differences were observed between normal and mutant plants. Increases in IVDMD and IVCWCD of as much as 33 and 43%, respectively, were associated with the presence of bmr genes.Variation among mutants in lignin concentration probably indicates that several different bmr genes were involved. Similarities between the bmr genes of sorghum and the bm genes of maize (Zea mays L.) suggest the possible existence of similar genes in other grasses, although their identification may be more complicated because of polyploidy.
Second‐brood Damage by Southwestern Corn Borer in a Corn Diallel Cross1
Authors: Scott Gene E. , Davis Frank M. 
Published: July 2010

Plants from reciprocal diallel crosses among nine (seven resistant and two susceptible) genotypes of corn (Zea mays L.) were evaluated for damage by second‐brood southwestern corn borer (Diatraea grandlosella Dyar). All plants were infested with southwestern corn borer eggs at silking time, and the extent of damage to the plant was determined 35 days later.Mean squares for maternal, reciprocal, and specific combining ability were small and generally not significant. Selections from populations 44# and 45# contributed a higher level of resistance to their crosses than did the other three resistant parents. The resistant ✕ resistant crosses had 36% fewer tunneled plants than the susceptible ✕ susceptible cross, and these tunneled plants had only 56% as much damage.
Evaluation of Potassium 3,4‐Dichloroisothiazole‐5‐Carboxylate as a Harvest‐Aid Chemical on Cotton1
Authors: Cathey George W. 
Published: July 2010

Chemical defoliants usually cause varying amounts of leaf abscission when applied to cotton (Gossypium hirsutum L.). This variation is due mainly to environmental factors, but may also be influenced by plant characteristics. The objective of this research was to evaluate the effect of potassium 3,4‐dichloroisothiazole‐5‐carboxylate (TD‐1123) in altering leaf abscission response of cotton to conventional defoliant chemicals. Field and greenhouse studies employed rates of TD‐1123 that varied from 0 to 1.12 kg/ha, and timing of application that ranged from 0 to 4 weeks before defoliant chemical treatments. Measurements were made to determine effects of rate and time of application of this chemical on leaf abscission, regrowth development, yield of seed cotton, and various boll and seed properties.TD‐1123 failed to alter leaf abscission response of greenhouse plants when applied as a mixture with DEF (S,S,S‐tributylphosphorotrithioate), but caused a significant increase in abscission rate and total defoliation when applied 1, 2, or 4 weeks prior to DEF. The 1 and 2‐week pretreatments, however, were the most effective in this respect. Regrowth development was also reduced in the 1 and 2‐week pretreatments of greenhouse plots, but was increased when applied 4 weeks before DEF. The rates of TD‐1123 that gave the greatest abscission response were 0.28 and 0.56 kg/ha. Seed germination, however, was reduced when these rates were applied 4 weeks prior to DEF.Regrowth, yield, and boll components of field cotton were not affected by TD‐1123 at rates of 0.28, 0.56, or 1.12 kg/ha. These rates, however, were equally effective in increasing leaf abscission response to DEF. A 10‐day pretreatment of 0.336 kg TD‐1123/ha also increased leaf abscission with sodium chlorate and with DEF + endothall [7‐oxabicyclo(2.2.1)heptane‐2,3‐dicarboxylic acid] mixtures. This research indicates that TD‐1123 can be an effective harvest‐aid chemical on cotton.
Inheritance of Stem Rust Resistance in ‘Webster’ Wheat1
Authors: Knott D. R. , McIntosh R. A. 
Published: July 2010

Inheritance of seedling resistance to stem rust (Puccinia graminis f. sp. tritici Eriks. & E. Henri.) in ‘Webster’ wheat (Triticum aestivum L.) was studied in testcrosses and in crosses with the ‘Chinese Spring’ monosomics. Studies in Canada and Australia showed that its resistance to several North American and Australian races of stem rust is controlled by the same nearly recessive gene, which is designated Sr30. Analysis of the monosomic crosses indicated that Sr30 is on chromosome 5D.The cultivar ‘Festiguay’, which also carries Sr30, was crossed with a Chinese Spring 5DL ditelocentric line, a 5DL ditelocentric line in which the telesomes carried Lrl, and a euploid marker stock homozygous for Lrl and Pm2. The results of these crosses indicated that Sr30 is on the long arm of chromosome 5D and is probably independent of the centromere, Lrl and Pm2. Pm is presumed to be on the short arm, with the order being Pm2 — the centromere — Lrl — Sr30.
Effects of Two Yield Component Selection Procedures on Maize1
Authors: Geadelmann J. L. , Peterson R. H. 
Published: July 2010

Breeders of maize (Zea mays L.) have been concerned with relationships between yield and yield components and the effects of plant density on these relationships. We used three inbred lines (A251, A556, and A619) and backcross‐selection procedures for kernel depth, ear length, and ears per plant to develop six modified versions of each inbred: deep kernel (D), long ear (L), multiple ear (M), deep kernel and long ear (DL), deep kernel and multiple ear (DM), and long ear and multiple ear (LM). A normal (N) inbred plus its six modified versions were crossed with their counterparts in each of the two other inbred backgrounds to produce seven types of single‐cross hybrids: N, D, L, M, DL, DM, and LM. The 21 hybrids were evaluated at plant densities of 24,700, 49,400, and 74,100 plants/ha in 2 years at two locations per year. The objectives of this study were to compare the effects of backcross‐selection for one vs. two of the yield components and to estimate the relative effects of such backcross‐selection on response of hybrids to plant density.Expression of the selected yield component in single component types of hybrids usually exceeded that of their normal counterparts. Increase in expression of selected yield components in double component types occurred only for ears per plant at low plant density and ear length at higher plant densities. Yields of D, L, M, DL, DM, and LM hybrids were −4.2, +3.6, +6.6, −8.0, +0.4, and −2.2%, respectively, of yields of N hybrids when averaged over plant densities and genetic backgrounds. Modified hybrids, particularly double‐component types, did not respond well to medium and high densities. Within the highest yielding hybrid background (A619 ✕ A251), no modified hybrid significantly exceeded the yield of the normal hybrid at any density. Within the limits of our evaluation, backcross‐selection for yield components does not seem to be a useful procedure for improving high yielding hybrids grown at plant densities common in much of the Corn Belt. It might be a useful breeding procedure to improve yield in specific circumstances, e.g., in relatively low yielding hybrid backgrounds, especially at lower plant densities.
Floral Initiation and Development in Cultivars of Oats1
Authors: Cisar G. , Shands H. L. 
Published: July 2010

Five cultivars of spring oats (Avena sativa L.), ranging in maturity from early to late, were planted on several dates in 1972 and 1973. Plant samples were collected from each cultivar starting at the four‐leaf stage and continuing at 3‐day intervals until anthesis was observed in apical florets. These samples were dissected to expose the reproductive axis in order to follow its seasonal development and to differentiate floral development patterns that influence panicle expansion in different cultivars to determine the effect of planting date on floral development and to compare floral development in the first and second tillers of the plant.Cultivar maturation was influenced by the length of time of the vegetative stage, the length of the reproductive phase as affected by rate and amount of primordia addition, and rate and amount of panicle elongation.Later planting dates hastened sexual maturity of all cultivars by shortening the vegetative stage, hastening primordium addition, and decreasing total panicle length. Panicle development in the second tiller paralleled that of the first tiller, hut was delayed 2 to 4 days.
Nitrate Reductase as a Factor Affecting N Assimilation During the Grain Filling Period in Spring Wheat1
Authors: Simmons Steve R. , Moss Dale N. 
Published: July 2010

In 1976 we investigated whether or not nitrate reductase (NR) enzyme activity in shoots of two spring wheat (Triticum aestivum L. em Thell) cultivars limits N assimilation during the grain filling (post anthesis) period. Twice weekly after anthesis NR activities in the flag leaf blade, flag leaf sheath, and first leaf blade below the flag leaf were estimated on field‐grown plants with an in vivo assay. Activity declined during the period in apparent association with senescence of the tissues. In contrast, when NR estimates were made by a modified assay in which no exogenous nitrate was supplied, activity was consistently low. This suggests that relatively little nitrate was available for reduction in these tissues although NR enzyme appeared to be there.The cultivars accumulated approximately 90% of their total reduced N before anthesis, as estimated by sequential sampling of shoots from the same plot area from which the NR samples were taken. Nitrogen accumulation after anthesis was predicted from the enzyme activities measured by both assay methods. Nitrogen accumulation predicted from the NR activities measured when nitrate was included was substantially greater than the accumulation actually observed. Our results suggest that the minimal accumulation of reduced N after anthesis by the cultivars in this study should not be attributed to the level of NR enzyme. It may be more a function of a limitation in a process responsible for supplying nitrate to the enzyme.
Alfalfa Yield, Specific Leaf Weight, CO2 Exchange Rate, and Morphology1
Authors: Hart R. H. , Pearce R. B. , Chatterton N. J. , Carlson G. E. , Barnes D. K. , Hanson C. H. 
Published: July 2010

Alfalfa (Medicago sativa L.) clones differ widely in CO2 exchange rates (CER) and in specific leaf weights (SLW); CER is correlated with SLW. If high forage yield could be shown to be associated with high CER, selection for high CER or SLW should result in improved forage yield.We selected plants with extremely high or extremely low SLW from several alfalfa populations and measured forage yields of clones propagated from these plants in the greenhouse and the field. Stems/plant, length and weight of the longest stem, the percentage of leaves on the longest stem, and SLW were determined at some harvests.The 116 clones studied in four experiments exhibited a wide range of CER, SLW, morphological characteristics, and yield. Correlations between yield and CER or SLW were small and in some cases negative. Yield per dm2 of leaf area was more closely correlated with CER (r = 0.26 to 0.28) than was total yield. SLW and CER were positively correlated in all experiments (r = 0.50 to 0.92). Yield was much more closely correlated with stem number, stem weight, and estimated leaf area (r = 0.60 to 0.91) than with CER or SLW. Neither CER nor SLW is an effective selection index for forage yield in alfalfa.
Yield Stability of Soybean Mixtures and Multiple Pure Stands1
Authors: Walker A. K. , Fehr W. R. 
Published: July 2010

The objective of our study was to determine the number of high‐yielding soybean [Glycine max (L.) Merr.] cultivars that should be grown in mixtures or in pure stands to obtain high yield and stability of production across environments. Eighty entries prepared from 28 high yielding pure lines with a 10‐day range in time of maturity were evaluated during 1975 and 1976 at six locations in Iowa. Yields in the 12 environments ranged from 11.1 to 39.2 q/ha. The entries, which included 14 of the 28 pure lines and six mixtures each for 2 to 10, 12, and 14 components, represented 12 levels of heterogeneity.There were no significant differences in yield between the mixtures and the mean of their components grown in pure stands (multiple pure stands). Regression of entry yields on an environmental index indicated that none of the pure lines, mixtures, or multiple pure stands had regression coefficients significantly different from each other or from unity. Average mean squares for deviations from regression were slightly smaller for mixtures than multiple pure stands and tended to decrease until mixtures had eight or more components. It was not possible, however, to define precisely the number of pure lines needed for stable production because mean squares for deviations from regression were more variable within than among levels of heterogeneity. Stable production depends on the particular cultivars or mixtures chosen as much as on the number involved. The choice between mixtures and multiple pure stands would depend on the yield of cultivars resistant to sporadic pest and soil problems, length of harvesting period desired, and the need to save pure seed.
Genetics of Seed Dormancy and its Association with Other Traits in Safflower1
Authors: Kotecha Ashok , Zimmerman L. H. 
Published: July 2010

Two selections of wild safflower (Carthamns palaestinus Eig.) possessing short‐term seed dormancy and three cultivars of domestic safflower (C. tinctorius L.) were used in crosses to study the genetics of seed (achene) dormancy and its association with other traits.Seeds from the parents of each cross differed significantly in all germination periods (24, 48, and 72 hours after 2 and 24 weeks of storage). Seed of all populations stored for 24 weeks had higher germination percentage than that stored for 2 weeks, which indicated that seed dormancy was lessened by long‐term storage. Variability of the F2 generation was of genetic origin, except in a few cases. Heritability in the broad sense ranged from 0 to 99% for 2 and 24 weeks of storage. Heritability estimates in the narrow sense were 55, 46, and 33% for 24, 48, and 72 hours of germination, respectively, for 2 weeks of storage. Except for one case, gene action was nonadditive. Seed germination characteristics were quantitatively inherited. The expectation of genetic advance for 48 hours of seed germination was higher than that of 24 and 72 hours of germination for 2 weeks of storage. Thus, selection for 48 hours of a 2 week storage period should be most desirable. Germination of seeds from plants with striped hulls and green midveins of cotyledons was higher than germination of those with nonstriped hulls and purple midveins. Correlation coefficients for all germination periods with seed weight and pappus were low. Correlation coefficients for seed weight with pappus were also low. Thus, these traits are not important in breeding for seed dormancy.
Lesion Nematode Resistance in Peanuts1
Authors: Smith O. D. , Boswell T. E. , Thames W. H. 
Published: July 2010

Six peanut (Arachis hypogaea L.) introductions and two commercial cultivars (‘Starr’ and ‘Spancross’) were evaluated for lesion nematode (Pratylenchus brachyurus (Godfrey) Felip & Sch. Stek) resistance under field conditions. Multiple harvests were used to compensate for maturity differences among peanut lines. Nematicide treatments were included to aid in evaluating the level of resistance.Shells of the peanut introductions PI 295233 and PI 290606 had significantly less pod discoloration and fewer nematodes from shell extractions than the commercial Spanish cultivars. Nematode extractions from root tissue supported the results from the shell samples. Three additional PI's showed lesser degrees of resistance.Subsequent comparisons among Starr, ‘Florunner’, PI 295233 and PI 290606 verified the results. Significantly more (P = 0.00036) nematodes were extracted from shell tissue of Starr and Florunner than of the other two entries. More nematodes (P=0.00003) were extracted from root samples of Starr than of the other three entries. The possibility that resistance is controlled separately in shell and root tissue is suggested.
Genetic Relationships Among Chemical Constituents in Seeds, Flower Buds, Terminals, and Mature Leaves of Cotton1
Authors: Hanny B. W. , Meredith W. R. , Bailey Jack C. , Harvey A. J. 
Published: July 2010

This experiment was conducted to determine the genetic association among chemical constituents considered to be associated with pest resistance of cotton (Gossypium hitsuture L.). Three replications of 39 cotton genotypes were grown in field plots at Stoneville, Miss. in 1977. Flower buds, terminals, and mature leaves of the genotypes were assayed for terpenoid aldehydes (including gossypol) and condensed tannis; seed were assayed for terpenoid aldehydes (including gossypol), oil, and protein. Cabbage looper [Trichoplusia ni (Hubner)] damage and lint percentages for all genotypes were determined.Seed and flower bud terpenoid contents were highly variable among genotypes. Although less variability was found for the remaining characteristics, all except leaf terpenoid content were significantly variable. Flower bud and terminal condensed tannins were significantly correlated (r = 0.67); each was moderately correlated with leaf condensed tannin (r = 0.41 and 0.45, respectively). Condensed tannin content of the plant parts was weakly correlated with terpenoid content.Lint percentages appeared to be independent of all chemical constituents measured. Seed oil was negatively correlated with flower bul (r _ ‐‐0.39) terpenoid content. Cabbage looper damage correlations of ‐‐0.46, ‐‐0.60, and ‐‐0.31 for flowerbud, terminals, and leaf terpenoids, respectively, were obtained. No relationship was found between looper damage and tannin content.
Genetic Control of Nitrogen Uptake and Translocation in Maize1
Authors: Pollmer W. G. , Eberhard D. , Klein D. , Dhillon B. S. 
Published: July 2010

Hybrid combinations of 10 flint with nine dent inbred lines of maize (Zea mays L.) along with 10 standard cultivars were evaluated in two environments. Four flint and four dent inbred lines were the result of a breeding program for high protein percentage in the grain and good combining ability for agronomic traits. The materials were harvested at two stages, i.e. at the beginning of the grain‐filling period and at grain maturity. Data based on stover, ear, and grain were collected to study N translocation from stover to ear during the grain‐filling period and N uptake in two phases of plant growth: the pre‐grain‐filling period (phase 1) and the grain‐filling period (phase 2).Highly significant differences were observed due to general combining ability (GCA) and specific combining ability (SCA) for total N uptake, N uptake in phase I, N uptake in phase 2, and N translocation. Genotype ✕ environment interactions involving both GCA and SCA contributed significantly to the variation for these traits. A high N uptake in phase 1 accompanied by a low N uptake in phase 2 seemed to increase the N translocation, depending on the capacity of the sink. The experimental hybrids, with high protein percentage and protein yield of grain, generally silked later than the conventional hybrids, but were at least comparable for percent ear dry matter at maturity and grain yield. This indicated a high rate of ear dry matter production and drying of the high‐protein hybrids. It is hypothesized that a high protein percentage and protein yield of mature grain, may be due to an intensive N uptake, a prolongation of the N uptake phase, and a high N translocation. The relative importance of these factors may vary in different genotypes and environments.
Inbreeding Depression of Selected F3 Cotton Progenies1
Authors: Meredith William R. 
Published: July 2010

The objective of this study was to investigate yield inbreeding depression of selected cottons (Gossypium hitsutum L.). In 1973, 360 F3 equivalent progeny rows from the cross and random intercross of ‘Deltapine 16’ ✕ ‘Mo 277‐396’ were grown at two Delta locations with two replications each. From 50 of the 72 highest lint‐producing progenies, F4 and F5 seed were produced in 1973 and 1974.In 1975, the 50 families were grown in five sets of 10 families each at two locations. Families were grown as whole plots; F3, F4, and F5 progenies were grown as subplots. An additional whole plot of Deltapine 16, Mo 277‐396, F1 F2, and the unsefected bulk of F3, F4 and F5 plants was grown in each set. The average lint yields of these seven populations were 633, 899, 859, 751, 725, 709, and 713 kg/ha, respectively. The average yields of selected F3, F4, and F5 progeny were 759, 748, and 710 kg/ha, respectively. Significant inbreeding depression was detected in both selected and unselected populations. These results imply that inbreeding depression is a major factor in the poor yield performance of early generation selections for yield in cotton.