bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inbreeding Medicago sativa L. by Sib‐mating. II. Agronomic Traits1
Authors: Aycock M. K. , Wilsie C. P. 
Published: July 2010

In two alfalfa (Medicago sativa L.) populations, (a) random population of noninbred ‘Vernal’ and (b) a composite S1 population derived from Vernal, the effects of breeding by self‐fertilization and sib‐mating were compared for certain agronomic traits. In general, as the degree of inbreeding increased, there was a reduction in spring vigor, forage yield, seed production, plant height aud width, and an increase in days to flower after first harvest. Also there was a trend toward more upright growth habit. Because the rate of inbreeding was less with sib‐mating than with selfing, the sib‐mated progenies were superior in performance to the selfed progenies.Inbreeding coefficients were computed for the several levels of inbreeding attained, and in general, the reduction observed in forage yield, spring vigor, and seed production was much greater than that expected in an autotetraploid species. The reduction in summer plant height and midsummer flowering was not as great. The use of sib‐mating in a breeding program and reasons for the rapid reduction in performance was discussed.
Twinning and Chromosome Anomalies in Kanota Oats1
Authors: Nishiyama I. , Tabata M. , Forsberg R. A. , Shands H. L. 
Published: July 2010

The frequency and chromosomec onstitution of twins in three Avena species (2n=42) were determined. A much higher frequency of twin seedlings was obtained from A. byzantina C. Koch var. ‘Kanota’ than from four other varieties of A. sativa L. and A. nuda L. Eighty‐four percent of 44 Kanota twins observed in 1966‐67 consisted of sister seedlings of different size. Seventeen of the 31 surviving smaller sisters and one of the larger ones had anomalous chromosome numbers, namely 63 (triploid) or Jess than 42. Of 86 pairs of Kanota twins in which both memberssu rvived, 36, 35, and 13 pairs were diplodiploid, diplo‐triploid, and diplo‐aneuploidty pes, respectively. One diplo‐haploid twin and one diplo‐diplo.triploid triplet were obtained.Variable numberos f trivalents, bivalents, and univalents were observed at metaphase I in 63‐chromosome plants (triploids). In each cell the number of bivalents and trivalents summedto 21, 22, or 23, which suggests that one or two bivalents were formed by autosyndesis. Twenty‐four percent of the extra 21 chromosomes in triploids failed to pair at metaphase I. These T1 plants had an average fertility of only 3.5%. Most of their T2 and T3 progenies still had more than 42 chromosomes but were markedly higher in fertility.Hypothesesf or the induction of polyembryonic kernels, especially the anomalous twin sister, are presented.
Feasibility of Hybrid Rice1
Authors: Craigmiles J. P. , Stansel J. W. , Flinchum W. T. 
Published: July 2010

Two rice varieties, representing a low tillering type and a profuse tillering type, were direct‐seeded and transplanted at seven plant densities to determine the effect of planting method and plant population on yield. Three year's results show that transplanted rice was more productive than direct‐seeded rice at all population densities with yields leveling off at 100 plants/m2 plant density. At all population densities the profuse tillering type was nmre productive than the low tillering type. With the developmem: of a cytoplasmic male‐sterile, the high cost of seed could be minimized by using low population rates without yield reductions. The greatest potential for F1 hybrids appears to be in the transplanted rice areas of the world.Segregating ratios from two sources of sterility could be explained by a single pair of recessive genes controlling sterility with one or more modifiers influencing the action. After a cytoplasmic male‐sterile has been developed it appears cross‐pollination will be the limiting factor in F1 hybrid seed production.
A Dynamic Population of Weedy Rye1
Authors: Suneson C. A. , Rachie K. O. , Khush G. S. 
Published: July 2010

Natural establishment and spread of a diverse and heterotic weedy rye population in California's northern mountain counties is reported. The dramatic take‐over by this interspecific derived population can be ascribed to a favorable climate and soil, and an unusual opportunity for continued introgression with diverse cultivars of rye.We encourage further study of this example of genetic introgression under conditions of natural selection. Information may be applicable to rye breeding, new species (Triticale) production, and population genetics. Its potential as a weed must also be considered.
Growth and Yield of Soybean Lines in Relation to Phosphorus Toxicity and Phosphorus, Potassium, and Calcium Requirements1
Authors: de Mooy C. J. , Pesek John 
Published: July 2010

High rates of P in pot experiments with three nutrient variables, P, K, and Ca, at 5 levels in a twice‐replicated 2(2n)+2n+1 composite design resulted in combination of growth responses and P‐toxicity effects, threshold leaf contents for which are given. Significant growth and differential responses among soybean [Glycine max (L.) Merrill] lines culminated in large yield responses with maxima at 450 to 500 kg P/ha. Differential growth effects developing in favor of a certain line may change between the 7‐leafed stage and the end of flowering in favor of another line. Treatments leading to maximum growth at the 7‐leafed stage contained too much P to proceed to maximmn growth and yield at later stages.Further screening of soybean lines should be directed at maximum nodulation or growth responses and minimum P‐toxicity hazard.
Floral Response, Winter Survival, and Leaf Mark Frequency of Advanced Generation Seed Increases of ‘Dollard’ Red Clover, Trifolium pratense L.1
Authors: Bula R. J. , May R. G. , Garrison C. S. , Rincker C. M. , Dean J. G. 
Published: July 2010

Varietal changes of Dollard red clover (Trifolium pratense L.) seed lots were of much smaller magnitude from the second to the third generations of increase than from the first (breeder) to second generations of increase. Changes in varietal populations during seed increases at Shatter and Tehachapi. Calif, were more pronounced than during similar increases at Prosser, Wash. Shifts toward more flowering type and fewer winter‐hardy plant populations were noted for some seed lots produced at Shatter and Tehachapi. However, under certain management treatments, the varietal populations from seed produced at these two locations were similar to the plant populations of the first generation seed. Seed produced at Prosser resulted in plant populations similar to those of the first generation seed. Changes induced at Prosser were toward more nonflowering and more winter‐hardy type plants compared to the first generation seed.A high correlation was noted between plant type and winter survival. No relationship was found between plant type or winter survival and leaf mark.
Heritability of Pod Dehiscence and Its Association with Some Agronomic Characters in Soybeans1
Authors: Caviness C. E. 
Published: July 2010

Individual plant measurements of parental, F1, and F2 populations and F3 progenies of four soybean crosses involving three varieties of the domestic species, (Glycine max (L.) Merr.), and a plant introduction of the wild species, (G. ussuriensis Regel and Maack), were used to determine heritability and associations of pod dehiscence (shattering) and some important agronomic characters in soybeans. Broad sense heritability estimates for pod dehiscence, date of flowering, date of maturity, and days from flowering to maturity generally were high (above 90%) and varied only slightly in the different crosses. Estimates for seed size varied from 40% in the cross between the largest and smallest seed parents to 69% in the cross between parents with the smallest seeds. There also was a tendency for the characters pod dehiscence, date of flowering, date of maturity, days from flowering to maturity, and seed size of individual Fe plants to persist in the F3 generations as indicated by highly significant regression coefficients.Genotypic and phenotypic correlation coefficients indicated that associations between pod dehiscence, and date of flowering, date of maturity, days from flowering to maturity, seed size, and oil and protein content presented no serious limitation to breeding for these characters, especially in crosses where both parents were classified as G. max. There was evidence of an association between pod dehiscence and date of maturity in two populations derived from crosses of the wild and domestic species and between pod dehiscence and seed size in one interspecific cross and in one cross involving only the domestic species.
Selection for Improving Creeping‐Rooted Characteristics in Alfalfa1
Authors: Busbice Thad H. , Hanson C. H. 
Published: July 2010

A phenotypic recurrent selection program for creeping‐rooted character in alfalfa was described. A random mating population, designated NCCrl, was obtained from selected segregates of crosses between Canadian creepers and adapted noncreepers. Normally, primordial domes are initiated on lateral roots the first growing season, but two growing seasons are required for expression of creeping‐rooted character. Four cycles of selection, using primordial domes as a criterion for creeping, failed to increase the frequency or amount of creeping. However, a fifth cycle of selection based upon actual creeping after 2 years in the field doubled the frequency and extent of creeping.All cycles of NCCrl were inferior to ‘Cherokee’ (adapted noncreepinig cultivar) in spring vigor, yield, and recovery after cutting. However, after five cycles of selection many creeping plants had upright growth, leaf shape, and vigor similar to that of Cherokee. In the last cycle of selection, creeping and vigor were positively correlated, indicating that these characters can be genetically combined.
Agronomic and Quality Characteristics of Awned and Awnleted Populations of Spring Wheat1
Authors: McNeal F. H. , Baldridge D. E. , Berg M. A. 
Published: July 2010

Awned and awnleted populations of spring wheat, Triticum aestivum L. em. Thell., derived by compositing seed from F2 plants and F3 lines classified as homozygous awned and homozygous awnleted, were compared for agronomic and quality performance at two locations. The awned population had heavier kernels and test weight at both locations and a 7% higher yield at one location. The awnleted population headed earlier and had more culms and more spikelets per head. Quality data showed the awnleted population superior in flour yield, loaf volume, farinograph stability, and farinograph valorimeter.The value of closely related populations for evaluating the effect of simply inherited characters is discussed.
Stomate Density and its Relationship to Water‐Use Efficiency of Blue Panicgrass (Panicum antidotale Retz.)1
Authors: Dobrenz A. K. , Wright L. Neal , Humphrey A. B. , Massengale M. A. , Kneebone W. R. 
Published: July 2010

Six clones of blue panicgrass (Panicum antidotale Retz.) representing three diverse sources of germ plasm were used to evaluate the association between stomate density and water‐use efficiency. Silicone rubber impressions were taken on the abaxial and adaxial leaf surfaces of four plants from each clone. Leaves were selected from the top, middle, and base of the culm and impressions were taken at the base, middle, and tip of each leaf.Stomate density of blue panicgrass clones ranged from 78 to 165 per mm2. Leaves adjacent to the inflorescence had significantly lower stomate density than those at the middle and base of the culm. No difference was found among stomate densities at the three positions on a leaf.A nonsignificant association was obtained when wateruse efficiency and stomate density were correlated for the six clones. Drouth tolerant clones had fewer stomates per unit area than drouth susceptible clones.
Effect of Floral Bud Removal on Performance of Soybeans1
Authors: Hicks D. R. , Pendleton J. W. 
Published: July 2010

Seed weight was increased such that the yield per plant of soybeans, Glycine max (L.) Merr., was not reduced when all floral buds were removed from any 1/3 section of the plant. When all floral buds were removed from either the upper or lower 2/3 of the plant, the increase in seed weight was not great enough to offset the reduction in the number of pods per plant, and, therefore, the yield per plant was reduced.Yield and number of pods per plant were reduced when all floral buds were removed from all the branches, but not affected when all floral buds were removed from the main stem. Seed weight was increased by both treatments. The vegetative parts of the plant without pods remained green until killed by frost; other parts of the plant senesced normally.Removal of floral buds (0 to 60 per plant at random over all nodes) had no effect on the number of pods per plant, seed size, or yield per plant. The protein content of the seed increased and oil content decreased as the number of floral buds removed increased.
A Rapid Method for Plant Leaf Area Estimation in Maize (Zea mays L.)1
Authors: Francis C. A. , Rutger J. N. , Palmer A. F. E. 
Published: July 2010

Total plant leaf area of individual maize plants (Zea mays L.) at anthesis was estimated by multiplying the area of leaf number seven, the best estimator in these studies based on correlation analyses, by an appropriate “leaf area factor.” This factor was determined by dividing total plant leaf area by the area of leaf seven, which was the largest or nearly the largest leaf for the 23 genotypes studied. For precise estimation, a factor should be determined for the largest leaf of each genotype or treatment in each population and each year. A very close correlation between estimated and actual leaf areas was observed when the leaf area factor was used.To minimize the error incurred by plant‐to‐plant variation, at least five plants should be completely measured to determine the leaf area factor for a given genotype. This method of estimation could be applied widely to leaf area measurements in maize and should make it possible to determine leaf areas in yield trials, breeding nurseries, and extensive field tests.
Inbreeding Depression in Diploid and Induced‐Autotetraploid Crested Wheatgrass1
Authors: Dewey Douglas R. 
Published: July 2010

Forage and seed yields of diploid crested wheatgrass, Agropyron cristatum (L.) Gaertu., were reduced sharply by selling. Some progenies were much more sensitive to selfing than others. Vigor and fertility reductions averaged 44.9 and 43.4%, respectively, in 15 S1 progenies. Inbreeding depression of induced‐autotetraploid crested wheatgrass was much less than that of comparable diploids. Forage yields of seven induced‐tetraploid S1 progenies declined 17.3%, compared with a 54.9% reduction for their exact diploid counterparts.Possible causes of rapid loss of vigor in natural autotetraploids are discussed. Newly synthesized autotetraploids—includiug crested wheatgrass; corn, Zea mays L.; Italian ryegrass, Lolium multillorum Lam.; and alsike clover, Trifolium hybridnm L.—show a much lower degree of inbreeding depression than old natural autotetraploids such as alfalfa, Medicago sativa L.; orchardgrass, Dactylis glomerata L.; and crested wheatgrass, Agropyron desertorum (Fisch. ex. Link) Schult. An accumulation of chromosome aberrations and unfavorable gene combinations in species buffered by autoploidy is offered as a major cause of excessive inbreeding depression in natural autotctraploids. The degree of inbreeding depression in natural autotetraploid species may give an indication of their relative ages.
Inheritance of the Capacity for Chloride Inclusion and Chloride Exclusion by Soybeans1
Authors: Abel G. H. 
Published: July 2010

Roots of Glycine max (L.) Merr. varieties absorb chloride ions in comparable amounts, but subsequent translocations of chlorides to plant tops is genetically controlled. Some varieties accumulate relatively large amounts of chlorides in plant tops; others exclude them almost completely. Chlorides occur in petioles and leaflets, with higher concentrations in leaflets, but whole leaf samples can be used to classify chloride‐accumulating capacity.The chloride includers growings in the saline soils of the Imperial Valley of California develop severe leaf necrosis from chloride toxicity, whereas the chloride excluders show no necrosisCrosses between parents with similar chloride accumulating capacity gave F2 and F3 progeny similar to parents in chloride content. In eight crosses from parents dissimilar in chloride accumulation, F2 plants segregated in ratios of 3 chloride excluder to 1 includer. In tests of the F3 progeny from these crosses, the F2 excluder plants segregated in ratios of 1 excluder to 2 segregating, whereas the F2 includer plants bred true.In backcrosses of the F1 plants from an includer by excluder cross, the segregating ratio was 1 includer to 1 segregating line when the recurrent parent was an includer and 1 excluder to 1 segregating line when the recurrent parent was an excluder.The gene symbols Nel and nel are proposed as the dominant for chloride excluders and the recessive for chloride includers, respectively.
Influence of Seedling Characteristics on Weed Competitive Ability of Sorghum Hybrids and Inbred Lines1
Authors: Guneyli E. , Burnside O. C. , Nordquist P. T. 
Published: July 2010

SummaryCompetitive ability of 48 sorghum [Sorghum bicolor (L.) Moench] hybrids and 41 parental inbred lines was evaluated using (a) germination percentage and germination rate index, (b) emergence percentage and emergence rate index, (c) seedling vigor, (d) rate of root and shoot development, and (e) cation exchange capacity of roots as selection criteria. Average response of sorghum hybrids was superior to parental inbred lines in all selection criteria. Sorghum lines selected for high and low seedling growth characteristics in laboratory and greenhouse studies showed corresponding competitive advantages over weeds in field studies. Competitive advantage of sorghum over weeds was largely due to rapid germination, emergence, and root and shoot growth during the early stages of sorghum development.
Relationship of Glucose Metabolism to Germinability and Vigor in Barley and Wheat Seeds1
Authors: Abdul‐Baki Aref A. 
Published: July 2010

Changes in glucose metabolism of germinating barley (Hordeum vulgate, L.) and wheat (Triticum aestivum L. em Thell.) were determined by following the rate of utilization of uniformly labeled glucose for respiration, and synthesis of proteins and polysaccharides (watersoluble sugars, starch‐hemicelluloses, and cellulose). Small changes in seed germinability or vigor induced by aging, led to a great reduction in glucose utilization as expressed by a reduction in protein and polysaccharide synthesis. The reduction in synthetic capacity greatly preceded any reduction in germination, shoot growth, or respiration.Besides its ability to detect very early changes in seed germinability or vigor, the glucose‐utilization approach offers a powerful tool for distinguishing dormant from dead seeds on the basis of the great difference in glucose metabolism in the two types of seed.
Modification of the Effects of 2,4‐D Inhibition of Growth and Lethality in Field Beans by Copper Sulfate and Copper Ethylenediaminetetraacetic Acid1
Authors: Huffaker R. C. , Sarquis A. V. , Miller M. D. 
Published: July 2010

The toxicity of 2,4‐dichlorophenoxyacetic acid (2,4‐D) on Phaseolus vulgaris L. as modified by two copper compounds was studied. Applying CuSO4 at 10−4 and 10−3M simultaneously with a growth inhibitory concentration of 2,4‐D (10−4M) reduced the inhibition significantly, allowing up to 47% greater dry weight and 44% greater trifoliolate leaf area 18 days after treatment. For maximum effect, only 1/10 as much CuSO4 (l0−3M) was required as the amount of iron compounds earlier found to be needed. CuEDTA began to affect inhibition of growth by 2,4‐D at a lower concentration than did CuSO4, but at maximum effectiveness was only half as effective as CuSO4.The time required to permanent wilting of primary leaves with 2,4‐D of 6.8 ✕ 10−3M was reduced by both CuSO4 and CuEDTA at concentrations generally ranging from 10−7 to 10−3M. With an added level of l0−2M, CuSO4 did not affect the time course significantly whereas CuEDTA extended it. With 2,4‐D of 1.4 ✕ 10−2M, however, CuEDTA and CuSO4 still reduced the time required to permanent wilting although each was needed in greater concentrations.
Genetic Control of Phytoglycogen Accumulation in Maize (Zea mays L.)1
Authors: Ayers John E. , Creech Roy G. 
Published: July 2010

Investigations of the role of the genes ae and su2 in phytoglycogen accumulation in maize endosperms were conducted by quantitating and characterizing the watersoluble polysaccharides (WSP) from the 16 genotypes of endosperm resulting from all possible crosses betweenlines homozygoufso r normal(Ae Su), ae, su1, and ae su1. The WSP was extracted in a mercuric chloride solution and enzymatically hydrolyzed to glucose, then measured as reducing sugar.Only the endosperms homozygous for su1 contained phytoglycogen. Increased doses of ae decreased the amount of phytoglycogen at 20 days after pollination from 38.8 to 4.2% of the dry weight. The β‐amylolysis limit of the phytoglycogen from the double mutant suggested that it may be a more loosely branched polysaccharide.
Carbon Uptake and Distribution Before and After Defoliation of Alfalfa1
Authors: Pearce R. B. , Fissel Guy , Carlson G. E. 
Published: July 2010

The deposition and redistribution of 14C was followed during the growth of individual alfalfa plants. 14CO2 was administered at 5 weekly intervals (plants were sampled 2 days after each addition of 14CO2). The plants were then defoliated, and the redistribution of 14C was followed during the subsequent growth.During the 1st week of 14CO2 uptake, only 17% of the 14C in the ]plant was translocated to crown and roots. By the 5th week, 36% of the 14C in the plant was in crown and roots. It was not until the 3rd week that 14C started to accumulate (exponentially) in the “starch” fraction. This coincided with the time that large roots (> 1 mm in diameter) started to increase in dry weight.After defoliation, 14C changes in the plant best fit a sigmoid curve. The greatest changes occurring between 3 and 15 days after defoliation. During the 28 days of regrowth, 45% of the 14C was lost (respiration, leaching, and sloughing) from the plant, 19% had moved into top growth and large roots had lost 70% of their original 14C content.
Nature of Heterosis in Grain Production by the Sorghum Panicle1
Authors: Blum A. 
Published: July 2010

Nine grain sorghum (Sorghum bicolor (L.) Moench) hybrids were compared with their parental lines in a field experiment on the manifestations of heterosis in grain production per panicle and each of the panicle weight components (i.e., number of whorls per panicle, number of branches per whorl, number of grains per branch, and weight per grain).Of all panicle weight components, a significant and consistent effects of heterosis (superiority over best parent) was found only hi the number of grains per branch, and mostly at the lower branches within the panicle. Component interaction did not account for heterosis in the number of grains per panicle, except in RS610 hybrid. It was indicated that heterosis in the weight per grain and in the number of grains per panicle were negatively associated.