bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association between Genetic Factors for Crown Rust Resistance and Yield in Oats1
Authors: Frey K. J. , Browning J.A. 
Published: July 2010

SummaryThrough a backcrossing program two series of oat (Avena sativa L.) lines were created, one early and one midseason, that were isogenetic except for genes that conditioned crown‐rust reaction. The lines were tested under crown rust epiphytotic and rust‐free environments, and three of the resistance genes were found associated with sizable deviations in grain yield under the rust‐free conditions. In both early and midseason genetic backgrounds the crown rust reaction gene from C.I. 8079, an Avena sterilis line, was associated with an increase in grain yield. The crown‐rust reaction gene from C.I. 7171 was associated with an increase in yield in the early genotype, but not in the midseason. The crown rust reaction gene from C.I. 7232, a derived tetraploid, was tested only in the midseason genotype in which it was associated with a 9.6% reduction in grain yield.
Natural Cross‐pollination in Blue Lupine (Lupinus angustifolius L.) in Georgia and Florida1
Authors: Forbes Ian , Leuck D. B. , Edwardson J. R. , Burns R. E. 
Published: July 2010

Natural cross‐pollination rates of blue lupine (Lupinus angustifolius L.) in Georgia and Florida ranged from 0 to 11.95% for different genotypes, test sites, test years, and honey bee population densities. The larger and fleshier‐flowered, earlier‐flowering biotype (common bitter blue lupine and ‘Rancher’ sweet blue lupine) had much lower cross‐pollination rates (0 to 3.45%) than the smaller and more fragile‐flowered, late‐flowering, elite winter‐hardy line 65G‐251. Nine other elite winter‐hardy lines were similar to 65G‐251 in floral, maturity, and cross‐pollination‐rate characteristics. We attribute the difference in natural cross‐pollination rates between the two major biotypes to their relative resistance to tripping by honey bees (Apis mellifera L.) or the flowering of the late type at temperatures more favorable for honey bee activity, or both.Results from tests including treatments designed to prevent flower‐visitation by one or more of the possible insect vectors of cross‐pollination indicate that: (i) Bumble bees (Pyrobombus spp.) easily tripped all types of blue lupine flowers and are cross‐pollination vectors, but their numbers were too few to be the principal vector; (ii) Honey bees were the principal cross‐pollination vectors; (iii) Thrips (Frankliniella spp.) were not cross‐pollination vectors, although they may render some flowers male sterile hy eating all the pollen; (iv) Wild bees were not vectors; and (v) Blue lupine is highly self‐compatible, highly self‐pollinated, and fully capable of automatic self‐pollination, i.e., self‐pollination within the closed flower is independent of insect visitation.In all tests at all locations cross‐pollination rates were positively correlated with honey bee population densities. Wind protection of the test site favored honey bee activity and higher cross‐pollination rates.We made suggestions based on these findings for use in breeding, genetic, and variety seed production operations.
Further Studies on the Inheritance of a Self‐Compatibility Response to Temperature and the Segregation of S Alleles in Diploid Alsike Clover1
Authors: Townsend C. E. 
Published: July 2010

Inheritance of a self‐compatibility response to a 32‐C temperature and segregation of S alleles were studied in the F1 and F2 progenies of a cross between two temperature‐sensitive I1 clones of diploid alsike clover (Trifolium hybridum L.). Temperature sensitivity (T) was inherited on a digenic banffs in the F1 progeny and was dominant to temperature insensitivity (t). The same two loci controlled temperalure sensitivity in both clones. The S alleles segregated in a l:l:l:l ratio. However, all temperature‐insensitive plants were of one S genotype.Of 10 F2 progenies evaluated, segregation for temperature sensitivity was 3 T:I t in three progenies, 15 T:I t in five progenies, and 9 T:7 t in one progeny. One progeny with a very high frequency of temperature‐insensitive plants did not fit any acceptable ratio. Segregation ratios for the S allele genotypes were influenced by S allele combinations and individual F1 parents.The data confirm the previously proposed two.gene model for the inheritance of temperature sensitivity in these two parent clones with an interaction between S allele genotype and temperature sensitivity.
Yield Components in Random and Selected Sugarcane Populations
Authors: James Norman I. 
Published: July 2010

Path‐coefficient analyses indicated stalk number was the most important component of yield of millable stalks per unit area in three sugarcane (Saccharum spp.) populations. Stalk diameter ranked second in order of importance in all three populations; stalk length ranked third in two populations and fourth in one population. Stalk density contributed less to cane yield than the other three variables.Stalk number, stalk diameter, and stalk length accounted for 82, 84, and 84% of the variation in yield in a random plant‐cane seedling population, random first ratoon clonal population, and selected plant‐cane clonal population, respectively.A negative association between stalk diameter and stalk number, and between stalk diameter and stalk density resulted in a low frequency of large‐diameter highyielding clones in these populations. Thus, a compromise in stalk diameter may be desirable to increase the frequency of high‐yielding clones in selected populations
Linkage Tests in Upland Cotton, Gossypium hirsutum L. II.1
Authors: Kohel R. J. 
Published: July 2010

Results of linkage analyses of cotton performed at College Station, Texas are presented, and linkage information reported by other workers is summarized. The mutants withering bract, accessory involucre, abnormal palisades, Ragged Leaf, round leaf, Red Dwarf, male‐sterile‐1, male‐sterile‐2, Male‐sterile‐4, and Ligon Lintless were tested for linkage with several marker loci and in various combinations among themselves.Ragged Leaf and round leaf were found to be linked (R.C. = 32 %), and thus form a new linkage group, number X. Data are presented to document the simple dominant inheritance of Ligon Lintless; the symbol Li is assigned to the mutant allele.
Effects of Leaf Area on Photosynthetic Rate, Light Penetration, and Grain Yield in Barley1
Authors: Berdahl J. D. , Rasmusson D. C. , Moss D. N. 
Published: July 2010

Related barley (Hordeum vulgare L.) lines, with small‐ and large‐leaf areas were developed and used to study the effect of leaf area on photosynthesis, light penetration, and grain yield. An infrared gas analyzer was used to measurep hotosynthesis of flag leaves in the laboratory and photosynthesis of plant canopies in the field. Light penetration into plant canopies was measured with tube solarimeters. LAI, grain yield, and the components of yield were determined in field plots.Photosynthetic rates per unit leaf area in the laboratory were similar in small and large flag leaves; thus, total photosynthetic activity per leaf was about twice as great in the large flag leaves. In field comparisons, however, no consistent differences in photosynthetic rates of small‐ and large‐leaf canopies could be detected, even though LAI's were greater in large‐ than in small‐leaf canopies by 19% in Population I and by 33% in Population II. Photosynthesis in the barley canopies as a whole was limited by lack of light throughout the entire range in intensity of solar radiation.In yield trials large‐leaf lines exceeded small‐leaf lines in flag leaf area by 70% and in LAI by 25%. Lines with small leaves produced more heads and higher grain yields than lines with large leaves when plants did not lodge. Where lodging occurred, however, large‐leaf lines had higher kernel weights and were higher yielding. We postulate that large leaves favor higher kernel weights and that small leaves favor production of more culms.
Leaf Area‐Leaf Weight Relationships in the Soybean Canopy1
Authors: Koller H. R. 
Published: July 2010

Leaf area (A) and leaf dry weight (LW) were determined throughout the growing season for lower, middle, and upper main stem segments and branches of a field soybean [Glycine max (L.) Merrill] community. The A/LW ratios were regressed on number of days after planting, using polynomial regression models. For the middle main‐stem segment, A was also regressed on LW.Mean seasonal A/LW decreased from the base to the top of the canopy. Mean A/LW of branches was higher than that of any main‐stem segment.The A/LW ralio of each main‐stem segment continually declined until just prior to leaf senescence. The trend subsequently reversed and A/LW increased rapidly during leaf abscission. The trend in A/LW of the branches differed in that there was an initial increase in A/LW, followed by a decline and then a second increase during leaf abscission.Due to time related changes in A/LW, models for the prediction of soybean leaf area from leaf weight should also include time as a variable if observations are made at different growth stages.
Seed Size Effects Upon Seedling Vigor of Three Forage Legumes1
Authors: Carleton A. E. , Cooper C. S. 
Published: July 2010

Seed size‐seedling vigor relationships were studied with birdsfoot trefoil (Lotus corniculatus L.), alfalfa (Medicago sativa L.), and sainfoin (Onobrychis viciaefolia Scop.). Differences in seed size were separated into those among plants and within plants. Seed weight distribution patterns were measured for each plant. An additional study measured the effect of varying number of seeds per raceme upon seed size of sainfoin.Correlations among clones of seed size with seedling vigor were significant in birdsfoot trefoil, were not significant in alfalfa, and approached a significant level in sainfoin. Differences in seed size within plants were highly correlated with seedling vigor in all legume species. The degree to which seed size can be affected by regulating seed number per raceme was shown for five sainfoin plants.Seed weight distribution patterns varied widely among plants within a species. The importance of these patterns in selecting for seedling vigor and in obtaining genetic equality in the contribution of plants to a composite variety is discussed.
Genetic Control of Leaflet Number in Soybeans1
Authors: Fehr W. R. 
Published: July 2010

The genetic control of leaflet number in soybeans [Glycine max' (L.) Merr.] was studied using a seven‐leaflet mutant (T255) found in the commercial three‐leaflet cultivar ‘Hawkeye’ and a five‐leaflet strain (T143) in the soybean genetic collection. The F1, F2, and F3 generations of the crosses Hawkeye ✕ T255, T143 ✕ Hawkeye, and T143 ✕ T255 were evaluated.The seven‐leaflet character was controlled by a single major gene (Lf2). Dominance of the Lf2 allele controlling trifoliolate leaves was complete in the Hawkeye ✕ T255 cross, but partial dominance was present in other genetic backgrounds. Multifoliolate leaves in T143 were controlled by a single major gene with partial dominance for the Lf1 allele controlling the five‐leaflet character. There was independent assortment of the two genes controlling leaflet number. Homozygous Lf1Lf1lf2lf2 individuals with up to 15 leaflets per leaf have been observed.Leaves of T255 with seven leaflets had a longer rachis by 8 mm and 9.4% greater leaf area than trifoliolate leaves of Hawkeye. No difference in seed yield was observed between Hawkeye and T255, indicating no yield advantage for plants with leaves with more than three leaflets.
Diploid Interspecific Hybrids of Tripolium pratense L., T. diffusum Ehrh., and Some Related Species1
Authors: Schwer J. F. , Cleveland R. W. 
Published: July 2010

Pollen from Trifolium hirtum All., T. diffusum Ehrh., and T. pallidum Waldst. & Kit. on pistils of T. pratense L. germinated and the tubes grew through the styles to the vicinity of the ovules. Likewise, pollen from T. pratense on pistils of T. diffusum and T. pallidum germinated, and the resulting tubes grew to the vicinity of the ovules. Compatible matings within T. pratense resulted in vigorous pollen tube growth, similar to that of the interspecific combinations.Matings of T. pratense with T. pallidum and T. hirtum produced no mature seeds. Embryos were collected at 7 days of age, but no hybrids were satisfactorily grown in embryo culture. Many hybrids were produced by mating T. pratense ✕ T. diffusum, but none were obtained from the reciprocal mating. Hybrids were generally chlorotic in the seedling stage, and chlorosis was observed on young leaves in older plants. Most floral and vegetative characteristics of hybrids were intermediate to the parents.All F1 hybrids of T. pratense ✕ T. diffusum were 2n = 15 and meiosis was very irregular. Univalents and bivalents at MI averaged 1.6 and 1.3 per cell, respectively. The remainder of the chromosomes were associated in complex multivalents of 3 to 15 members. Most multivalents were chains, and bivalents were rods. Up to three bridges with fragments were found at AI, and bridges were also seen at All. These chromosomal abnormalities indicate the presence of translocations and paracentric inversions. It was concluded that T. pratense and T. diffusum had complex differences in chromosome structure.The F1 of T. pratense ✕ T. diffusum was nearly sterile. However, backcrosses to T. pratense produced a few plants that may have been polyploids. The BC1 plants flowered and were partially fertile.
Frequency Changes of Isozyme Alleles in a Selection Experiment for Grain Yield in Maize (Zea mays L.)1
Authors: Stuber C. W. , Moll R. H. 
Published: July 2010

Frequencies of alleles associated with three peroxidase isozyme systems and one acid phosphatase system were monitored through nine cycles in a maize (Zea mays L.) selection program for grain yield that originated from (NC7)✕ CI21) syn 2. The same isozymes were also evaluated in an unselected population following 20 generations of random mating of (NC7)✕ CI21) syn 2. for the three peroxidase systems the dominant alleles became fixed in both the unselected and selected populations.Two codominant alleles (F and S) were found in the acid phosphatase system with the heterozygote exhibiting two parental bands and an intermediate hybrid band. Frequency of the F allele increased from 0.50 to 0.76 in the first six cycles of selection; however, it now appears that the population is approaching a stable intermediate frequency (0.60). Although the changes in frequencies suggest an association of this acid phosphatase locus with yield, close linkage with another "yield" locus cannot be ruled out.
Maize Fodder—Influence of Barrenness on Yield and Quality1
Authors: Marten G. C. , Westerberg P. M. 
Published: July 2010

Our objective was to establish the relative yield potential and quality of high‐sugar, male‐sterile (barren) vs. normal, male‐fertile (fruited) maize (Zea mays L.) for silage crops. We produced fodder from a male‐sterile and a male‐fertile cultivar by procedures causing both barren and fruited plants of both cultivars during each of two years. Feed quality, dry matter yield, and digestible dry matter yield were determined for husked ears, stover, and fodder.Barrenness reduced in vitro digestibility of fodder from the male‐fertile cultivar, but it did not affect digestibility of the male‐sterile. However, total non‐structural carbohydrate concentration of the fodder was greatly reduced by barrenness of both cultivars. Crude protein of the fodder was not affected by barrenness.Fruited plants yielded 20% more fodder dry matter than barren plants of both cultivars. The fruited plants also yielded more digestible dry matter (22 to 27% more than barren plants).We confirmed the hypothesis that preventing grain formation in maize reduces its efficiency in producing fodder dry matter. Our results show that maize breeders are likely to produce higher yielding, high quality silage cultivars by developing male‐fertile, fruited genotypes instead of male‐sterile, high‐sugar genotypes.
Delayed Flowering of Saccharum spontaneum L. and Related Hybrids
Authors: James Norman I. 
Published: July 2010

Artificial light from 12 midnight to 2 a.m. each night for various periods prior to floral initiation drastically reduced intensity of flowering of most Saccharum spontaneum clones and delayed emergence of those panicles that did emerge in some clones as much as 105 days.A 12.5‐hr photoperiod for 3 or 4 weeks after floral initiation occurred naturally delayed flowering of backcross progeny of S. spontaneum ✕ commercial‐type Saccharum sp. hybrids an average of 12.4 days with a range from 0 to 25 days among clones.
Influence of Temperature at Various Growth Stages of Oat Cultivars. I. Utilization of Controlled Environment Chambers, Climatological Data and Developmental Growth Stages1
Authors: Taylor G. A. , Frey K. J. 
Published: July 2010

An approach is discussed that permits an evaluation of genotype ✕ temperature and growth stage ✕ temperature interactions in oats (Avena sativa L.). Methods were developed that permitted the assay (a) of genetic differences for tolerance to temperature stress among four oat cultivars and (b) of reactions of four oat cultivars when stress temperatures were applied at several growth stages.Controlled environment chambers were programmed to simulate climatological data for the Iowa oat‐growing season of April through June. Three temperature levels (high, control, and low) were imposed at five growth stages (initiation and differentiation of tillers, differentiation of floral reproductive structures, elongation of shoot apex, anthesis, and grain filling) on four diverse oat cultivars.Even though an experimental unit consisted of only one plant per 4‐inch pot, the precision of experimentation, measured by coefficients of variation (CV), was quite acceptable. The CV's for seed yield varied from 8.2 to 9.6%, similar to oat yield trials in the field where the sample size is about 500 plants.
Inheritance of Resistance to Isolates of Fusarium oxysporum var. batatas in Burley Tobacco1,3
Authors: Jones J. L. , Gupton C. L. , Terrill T. R. 
Published: July 2010

Two genetic experiments designed for diallel analysis and generation means analysis were utilized to study the nature of gene action conditioning resistance to four isolates of Fusarium oxysporum var. batatas in burley tobacco (Nicotiana tabacum L.). Plants were evaluated for their reaction as seedlings in the greenhouse. The diallel experiment, consisting of all possible crosses among five burley tobacco parents, was analyzed according to the procedures of Griffing and Jinks‐Hayman. The generation means experiment included the P1, P2, F1, F2, P1F1, and P2, F1 generations of the cross between ‘Kentucky 12’ and ‘Judy's Pride.’General combining ability mean squares and Hayman's D (additive component) were highly significant for each isolate. There was close association between the ranking of the parental entries for general combining ability effects and parental performance per se, indicating that predictions of Fl hybrid performance can be made from parental performance. The generation means analyses showed additive gene effects to be most important and dominance and epistatic effects to be relatively unimportant in the inheritance of resistance to each of the isolates and their mixture. Narrow‐sense heritability estimates indicated that rapid genetic advances through selection could be made for resistance to Fusarium wilt.
Genetic Effects Estimated from Generation Means in Four Diallel Sets of Maize Inbreds1
Authors: Darrah L. L. , Hallauer Arnel R. 
Published: July 2010

Genetic parameters were estimated from generation means in four types of maize (Zea mays L.) inbred lines: first cycle lines, isolated from open‐pollinated varieties; second cycle lines, isolated from either planned pedigree crosses or synthetic varieties; good lines per se; and poor line per se. Nine generations were available for each cross: parents, F1, F2, F3, backcrosses, and backcrosses selfed. Parameters estimated were additive, dominance, and digenic epistatic effects.Second‐cycle inbreds demonstrated significantly more epistasis for yield than did first‐cycle inbreds. Good and poor inbreds were similar and intermediate to first‐ and second‐cycle inbreds in the occurence of epistasis, which occurred in 30% of the crosses. Interactions of environments ✕ additive and dominance effects were significant in more than two‐thirds of the crosses. The environments ✕ epistasis interactions were significant in 25% of the cases for the poor inbreds.Dominance effects were several times larger than additive effects for all crosses. Pooling of effects over loci is discussed as the reason for disagreement with results of variance analyses. Additive ✕ additive and dominance ✕ dominance interactions were present in half the crosses of the poor inbreds. Significance of epistatic effects and additive effects was found in about the same frequency in the other types of inbreds.Correlation analyses indicated the nonepistatic model sufficient to describe the gene action, since all r values exceeded 0.9**. The full model including epistatic terms was of value in describing a particular environment, but the epistatic terms were of no value when predicting yield in one environment from trials in a different environment.
Effect of Timing of Irrigation on Total Nonstructural Carbohydrate Level in Roots and on Seed Yield of Alfalfa (Medicago sativa L.)1
Authors: Cohen Y. , Bielorai H. , Dovrat A. 
Published: July 2010

This study was undertaken in order to assess the effect of certain soil moisture regimes, manipulated by timing of irrigation, on the seed yield of alfalfa (Medicago sativa L.)Sprinkler‐irrigated alfalfa (cv ‘Hairy Peruvian’) was cut once and the regrowth was left for seed production or cut periodically for forage during the spring to midsummer period. Seed plots were irrigated either at day 10 or 23, or both (following cutting) to 180‐cm soil depth. Forage plots were irrigated once immediately after each cutting.Irrigation at day 23 resulted in a considerably lower rate of foliar regrowth during the 1st 3 weeks following cutting than when irrigation was applied at day 10. Slow regrowth was conducive to greater accumulation of total nonstructural carbohydrate (TNC) in roots than quick regrowth. High TNC level in the roots was associated with high percentage of pods set and with high seed yield. Irrigation both at day 10 and also at day 23 increased the flowering intensity that was associated with a lower percentage of pods set than the other treatments. The seasonal decline of TNC in the roots of plants harvested for seed was smaller than that in the roots of plants cut for forage.It was concluded that timing of irrigation that leads to an increase in the root reserves during the period of initial regrowth is likely to increase the seed yield potential of alfalfa.