bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inbreeding Medicago sativa L. by Sib‐mating I. Cross‐, Sib‐, and Self‐Fertility1
Authors: Aycock M. K. , Wilsie C. P. 
Published: July 2010

Sib‐mating without selection was compared with selling as a method of inbreeding alfalfa. Through two generations, the drastic loss in fertility following self‐fertilization was reduced by approximately half through the slower form of inbreeding (sib‐mating).In two populations, (a) a random population of noninbred ‘Vernal’ and (b) a composite S1 population derived from Vernal, self‐fertility was significantly correlated with sib‐ and cross‐fertility. Heritability estimates indicated that fertility was highly heritable.Inbreeding coefficients were computed for the several levels of inbreeding attained and, in general, the reduction in fertility observed was much greater than that expected in an autotetraploid species. Reasons for the rapid loss in fertility following inbreeding and the possibilities for continuing sib‐mating for several more generations are discussed.
Photosynthesis in Plant Communities as Influenced by Leaf Angle1
Authors: Pearce R. B. , Brown R. H. , Blaser R. E. 
Published: July 2010

Flats of barley were seeded at three different rates and tilted at 0°, 30°, and 60° from the horizontal. When the first leaf had developed the flats were returned to the horizontal for measurements of photosynthesis, light penetration, and leaf area index. This method produced flats with uniform leaf angles of 90°, 53°, and 18° at different leaf areas.Results showed that differences in net photosynthesis, due to leaf angle, increased as leaf area index (ratio of leaf area to soil area) increased above two. The vertical leaves had a higher Pn and allowed more light to penetrate at high LAI's than horizontal leaves. Leaves at 90° required a leaf area index of 11 to intercept 95% of the light; 53° and 18° leaves intercepted 95% of the light at LAI's of 7 and 4.5, respectively. The mean extinction coefficients were 0.32, 0.45, and 0.60, respectively, for leaves 90°, 53° and 18° to the horizontal.When data from these experiments were analyzed in equations proposed by Saeki to predict the net photosynthesis of a plant community, the predicted results closely approximated experimental results.
Differential Seed Production of Alfalfa Clones at Two Diverse Locations1
Authors: Dade Eugene , Taylor Norman L. , Garrison C. S. 
Published: July 2010

Twenty‐three alfalfa clones selected from the breeding program at the University of Kentucky were grown at Lexington, Ky., and at Prosser, Wash., in 1962 and 1963. Data were taken on date of bloom and seed yields. Flowering began later at Lexington than at Prosser in both years, but clipping at Lexington in 1963 prevented a direct comparison between locations. The range in days to first flower within the group was greater at Prosser but was considered slight in relation to the long pollination period at Prosser. Seed yields were higher at Prosser in both years. A substantial differential in seed yields of the clones at the two locations was revealed.It was concluded that seed‐yield data from alfalfa clones grown in Kentucky could not be used to predict the reproductive capability of the clones in an environment which favors a more complete expression of seedyield potential. A correlation of r = .86 between the lst‐year and 2nd‐year seed yields indicates that clones could be screened for seed yields at Prosser in the 1st year.
Inheritance of Cytoplasmic Malesterility in Sudangrass1
Authors: Alam Sultanul , Sandal P. C. 
Published: July 2010

Inheritance of cytoplasmic male‐sterility was studied in F2 and BC1 generations within crosses of male‐sterile Sorghum arundinaceum var. Rhodesian with six lines of sudangrass, Sorghum vulgare var. sudanense. All F1 progenies were male‐fertile indicating that the males carried dominant fertility restorer genes.Based on the segregation of male‐fertile to male‐sterile plants in the F2 and BC1 generations, male‐sterility was conditioned by one gene pair in three crosses, two gene pairs in two crosses and by three gene pairs in one cross. Fertility was dependent on at least a single dominant fertility restorer gene at each of any two of the three gene loci identified.
Mass Selection by Specific Gravity for Protein and Oil in Soybean Populations1
Authors: Smith R. R. , Weber C. R. 
Published: July 2010

The effects of two cycles of mass selection by specific gravity were investigated in two hybrid soybean populations (Glycine max (L.) Merrill). Effects were measured on chemical composition and on six agronomic attributes. Selection was employed for high (Hi) and low (Lo) specific gravity within each population. A solution of glycerol and water was used to establish the desired specific gravity. Cycle 1 stratified the original populations into groups differing in chemical composition. Hi populations had a higher mean protein and lower mean oil content than the control populations. Lo populations were above average in oil and below average in protein content. Protein increased in the Hi populations and ranged from 0.3 to 1.2% and the decrease in protein in the Lo populations ranged from 0.6 to 1.5%. The increase in oil in the Lo populations ranged from 0.1 to 1.0% and thedecrease in oil in the Hi populations ranged from 0.0 to 0.9%.The effects of continued selection (cycle 2) varied among and within populations. In general, selections in cycle 1 were more effective than in cycle 2 for protein and oil.Specific gravity measures relative density; therefore, density of the seed was determined using a Bechman gaspycnometer. Average heritability for seed density was 69%. High seed density was associated with high protein, low oil and late maturity.
Differences in Response to Mineral Nutrients of Populations of Ryegrass, Lolium perenne L., and Orchardgrass, Dactylis glomerata L.1
Authors: Crossley G. K. , Bradshaw A. D. 
Published: July 2010

The growth response to mineral nutrients of natural populations of Dactylis glomerata and Lolium perenne determined (a) in sand culture with varying levels of calcium and phosphate and (b) in calcareous, acidic, and ordinary soils showed considerable differences in response of populations from contrasting soil types, suggesting specific physiological adaptation to soil nutrient level. Cultivated varieties which were included usually performed best under ordinary nutrient conditions. But under extreme conditions they rarely performed as well as the specifically adapted natural populations. Seed/ tiller comparisons suggested a high heritability of response.Material of cultivated varieties collected after seed multiplication, or from established awards, showed that genetic changes in physiological adaptation of varieties can occur when they are grown on extreme soils. In seed multiplication such changes are likely to be agriculturally disadvantageous. Edaphic differentiation and evolution in herbage plants may therefore be more widespread and Important than previously considered.
Inheritance of Tolerance in Flax (Linum usitatissimim L.) Treated with MCPS1
Authors: Stafford R. E. , Comstock V. E. , Ford J. H. 
Published: July 2010

Progeny arising from crosses between 2‐methyl‐4‐chlorophenoxyacetic acid (MCPA)‐tolerant and MCPA‐susceptible flax varieties were evaluated for MCPA tolerance in F3, F4, BC(S2), and BC(S3) generations. Data were obtained on the change in anthocyanin production and stem curvature, delays to first bloom, full bloom, and maturity, and on the reduction of plant height andseed yield.Based on heritability estimates, selection would be most effective for change in anthocyanin production, stem curvature, and reduction in plant height in the ‘Arrow’ ✕ ‘Dakota’ cross and most effective for stem curvature, and delays to first bloom and to maturity in the Arrow ✕ C.I. 1139 cross.
Second Phase in the Evaluation of Synthetic Varieties of Maize for Yield1
Authors: Hallauer Arnel R. , Sears J. H. 
Published: July 2010

The second phase of a sequential synthetic variety testing program for yield in maize (Zea mays L.) is reported. Four varieties selected from the tests of the first phase and five previously untested varieties were crossed in a diallel series and evaluated at three locations in each of two years.The yield level of the varieties included for the first time was generally higher than those selected from the first phase. Two‐ear Syn., Syn. AA, and Syn. BB were the highest‐yielding varieties, whereas S.S. Syn. and Purdue MJ yielded significantly lower than the other varieties. S.S. Syn. was outstanding in cross performance; it had the highest average yield in crosses and a significant, positive general combining ability effect. Two‐ear Syn. was high in both variety and cross performance and had the largest variety effect ( = 3.44**).Relative to the midparent and high parent, average heterosis for all crosses was 9.8 and 4.2%, respectively. Relative to the high parent, S.S. Syn., L.E. Syn., and C.B. Syn. #3 exhibited the most heterosis in crosses. S.S. Syn. ✕ Pa. Int. Syn. had a significant, specific heterosis effect ( = 5.51**) and an observed heterosis of 24.1% relative to the midparent. Very little heterosis was observed for the crosses involving Syn. AA and Syn. BB. Specific heterosis (s.c.a.) was significant (P < .05) in the combined analysis. The specific effects for only three crosses were larger than the standard error: S.S. Syn. ✕ Pa. Int. Syn. had a positive effect, and Syn. AA ✕ Pa. Int. Syn. and Syn. BB ✕ S.S. Syn. significant, negative effects. The cross, S.S. Syn. ✕ Pa. Int. Syn., was the highest yielding in both phases of testing.
Growth and Carbohydrate Storage of Three Poa pratensis L. Strains as Influenced by Temperature1
Authors: Youngner V. B. , Nudge F. J. 
Published: July 2010

To determine if Poa pratensis strains of different origins would respond differently to a series of temperatures, ‘Merion,’ ‘0217,’ and ‘Newport’ cultivars were grown in controlled environment growth chambers at four different temperature regimes.Top growth, density, and total available carbohydrates in stem bases were determined after 8 weeks in the growth chambers. Plants were clipped to 4 cm at weekly intervals during the treatment period.A differential response to temperature among the three strains was demonstrated. Merion and 0217 had the highest density at the higher temperatures and Newport had the highest density at the lower temperature regimes. The 0217 strain had significantly greater density at all temperatures than did Merion or Newport. All strains accumulated more carbohydrate reserves at the lower temperatures, but Newport had signficantly lower reserves at all temperatures than did Merion or 0217. Only Merion had a significantly greater carbohydrate reserve at the lowest temperature compared to the next warmer regime. Clipping yields were greater at the warm temperatures compared to the cool temperatures for all strains.
Differences in Free Amino Acids Between Stocks of the Same Long‐Time Inbred Line of Maize (Zea mays L.)1
Authors: El‐Eryani A. A. , Fleming A. A. 
Published: July 2010

Qualitative analysis was made for free amino acids by two‐dimensional descending paper chromatography in four stocks of long‐time corn inbred CI 7 (Zea mays L.).We detected eight amino acids in 60 lambdas of the North Carolina and Arkansas sources, whereas only four were found in the stocks from Athens and Beltsville. However, seven amino acids were detected in 100 lambdas of the Athens and Beltsville stocks. Apparently, the North Carolina and Arkansas stocks differ quantitatively, rather than qualitatively, from the Athens and Beltsville stocks with respect to the free amino acids—asparagine, glutamine, glycine, and probably arginine. These findings are in agreement with a previous report by us on variations between these stocks for seedling and quantitative biochemical characters.Stocks within supposedly homozygous lines may differ in the number and/or amount of amino acids present in the seedlings. Thus biochemical analyses may become more useful as techniques in the identification and isolation of genotypes in breeding programs and in basic genetic and cytogenetic studies.These variations may be due either to mutation or residual heterozygosis, or to both. The possibility of episomal systems or regulatory genes as a part of mutation or residual heterozygosis should not be overlooked.
Differential Survival of Cool Season Turfgrass Species Overseeded on Different Selections of Bermudagrass1
Authors: Kneebone William R. , Major Gary L. 
Published: July 2010

In a 2‐year study at Tucson, Ariz., marked reductions occurred from initial stands of four cool season grasses overseeded for winter turfgrass on certain varieties of bermudagrass (Cynodon dactylon (L.) Pers.) while stands were maintained on other bermudagrass varieties. The cool season grasses studied were Pennlawn fescue (Festuca rubra L.). annual ryegrass (Lolium multiflorum L,.), roughstalk bluegrass (Poa trivialis L.), and a mixture of highland bentgrass (Agrostis tenuis Sibth.), Kentucky bluegrass (Poa pratensis L.), and Pennlawn fescue. The stand reductions were most apparent with annual ryegrass and the grass mixture. Initial stands of all cool season grasses on all bermudagrasses were above 90%. These stands were maintained until the spring transition on seeded Arizona bermudagrass while stands of the ryegrass reduced to below 75% in late February and March on ‘Tiflawn,’ ‘Tifway,’ and ‘Ormond.’ Ryegrass stands on ‘Tufcote,’ ‘Beltsville #1,’ and ‘Midway’ averaged 89% in the spring compared to 94% on seeded Arizona bermudagrass.Differentials in soil nitrogen levels could not be shown among the 16 bermudagrasses studied. No apparent disease affected cool season grass stands. Extracts from bermudagrasses with contrasting cool season grass stands were used to moisten annual ryegrass seeds in a germination study. There were no germination differentials. Ryegrass grown in the greenhouse and on an outdoor bench on plugs of Arizona bermudagrass maintained stand while ryegrass stands on plugs of Ormond were reduced.
Effect of Seed Source and Seedling Age on the Freezing Resistance of Winter Oats1
Authors: Marshall H. G. 
Published: July 2010

Controlled freezing experiments were used to study the effect of the location where seed is produced on the freezing resistance of young winter oat plants (Avena byzantina K. Koch and A. saliva L.). Plants grown from Pennsylvania seed were significantly more resistant to freezing at early ages than those grown from Virginia seed, but seed source was not always important. Differences associated with location where the seed was grown disappeared as the plants aged, and the duration of the effect varied with the variety. The effect persisted as long as 26 days for the variety 'Ballard.' Seedling plants of the variety 'Wintok' had a moderate freezing resistance at 12 days of age, but this decreased to a first minimum at 19 days of age. The freezing resistance then rapidly rose to a maximum at 33 days of age, but a second decrease occurred after 33 days.Limited data on chemical composition of the seed supported the hypothesis that the source effect was caused by differences in the nutrient reserves developed in the endosperm at different geographic locations. Freezing resistance was lowest when the N level in the seed was high, and highest when the P and K were high and the N level low.
Estimates of Genetic Variance in ‘Cherokee’ Alfalfa (Medicago sativa, L.)1
Authors: Dudley John W. , Busbice T. H. , Levings C. S. 
Published: July 2010

Four blocks of clones (17, 18, 19, and 20 clones per block) taken at random from ‘Cherokee’ alfalfa (Medicago sativa L.) were evaluated in a partial diallel mating design. Vegetatively propagated clones and four cross progeny from each clone were evaluated in three replications at two locations for 2 years in the upper coastal plain of North Carolina. Variance components estimated were interpreted in terms of autotetraploid inheritance with alpha = 0. Significant estimates of total genetic variance (δ2c), general combining ability variance (δ2g), and covariance of parent‐offspring (δpo) were obtained for yield, recovery after cuts 1 and 2, spring growth, and fall growth. Estimates of specific combining ability variance (δ2s) were not significant for any character. However, estimates of δ2c were significantly larger than estimates of 2 δpo or 4 δ2g for forage yield, recovery after cut 1 and spring growth indicating that either trigenic, quadrigenic, or epistatic genetic variance was important.Predicted gain in yield from selecting the upper 10% of the clones and recombining them into a synthetic was 9.3%. Because both additive and non‐additive genetic variance are important in Cherokee, additional gain might be made by producing hybrid varieties.
Inheritance of Multifoliolate Leaves, Glabrous Leaves, and Petiolulate Leaflet Attachment in Crimson Clover, Trifolium incarnatum L.1
Authors: Knight W. E. 
Published: July 2010

Inheritance of multifoliolate leaves, glabrous leaves, and petiolulate leaflet attachment was studied in the F1, F2, and F3 generations of crimson clover, Trifolium incarnatum L. Normal crimson clover has trifoliolate, pubescent leaves and sessile leaflet attachment. Inbred, recessive white‐flowered lines were used as the female parent in studying these mutants: glabrous leaves (g); petiolulate leaflets (p); and multifoliolate leaflets (mI). Segregation ratios for multifoliolate leaves, glabrous leaves, and petiolulate leaflets fit expected segregation ratios of 3:1. Each of the characteristics studied appears to be controlled by a single recessive gene pair. Intermediate forms were not observed, an indication that only a single gene pair was involved in each mutant. One mutant was a double recessive with glabrous leaves and petiolulate leaflet attachment. Heterozygous F2 and F3 populations from the double recessive segregated on the basis of a 9:3:3:1 ratios as expected; thus showing independent inheritance for these two characters.The following genetic symbols are proposed: G for pubescence, and g for glabrous; P for sessile leaflet attachment and p for petiolulate leaflet attachment; and Ml for trifoliolate leaves and ml for multifoliolate leaves.These characteristics should help determine effective hybridization in the crossing and breeding program. As more marker genes are accumulated, specific chromosomes and chromosomal regions can be identified. Some of these mutants will be of interest morphologically and of possible value as physiological indexes, e.g., multifoliolate leaves.
Delayed Flowering and Pollen Production in Male‐Sterile Sugarcane Subjected to Extended Day‐Length1
Authors: James Norman I. 
Published: July 2010

Six early‐ to mid‐season flowering sugarcane clones (Saccharum officinarum L. ✕ S. sinense Roxb. ✕ S. spontaneum L.) that are highly male sterile were subjected to a 12‐5‐hour photoperiod for 2, 4, and 6 weeks between September 13 and October 25. The 2‐ and 4‐week treatments were applied at the beginning and toward the end of the period.Longer durations of treatment caused greater delay of flowering, and a given duration caused greater delay of flowering when applied toward the end of the period. Maximum delay of flowering among clones ranged from 10 to 72 days. The earliest flowering clone could be crossed with all mid‐season flowering clones, and the midseason flowering clones could be crossed with most, if not all, late‐flowering clones of interest in the crossing program.All clones produced pollen after flowering was delayed, and they were effective pollen parents. Delay of flowering to first pollen shedding ranged from 13 to 32 days among clones.
Use of Carbohydrate and Nitrogen Root Reserves in the Regrowth of Alfalfa from Greenhouse Experiments under Light and Dark Conditions1
Authors: Smith Dale , Silva Jorge P. 
Published: July 2010

Alfalfa (Medicago sativa L.) plants were allowed to regrow 42 days in the dark and light with and without (roots only) intact crowns. A significant amount of new roots was produced only on actively photosynthesizing plants. No major change in fresh weight‐unit volume of the original roots was noted, except for an increase during the period of 21 to 42 days with plants grown undisturbed in the light which then were actively reaccumulating root reserves.A small proportion of the root nonstructural carbohydrates, but none of the total nitrogen, was used in root respiration. Most of the nonstructural carbohydrates were translocated from the roots and used for the production of new tops and roots, and root carbohydrates were used in far greater amounts than root nitrogen. Even so, photosynthate from new leaves was an important factor in recovery growth. Current photosynthetic energy contributed 0, 52, 70, 83, 89, and 93% of the increase in total plant weight of plants grown undisturbed in the light at 7, 14, 21, 28, 35, and 42 days, respectively.
Inheritance of Yield, Forage Quality and Seed Characteristics in Sericea Lespedeza1
Authors: Cope W. A. , Moll R. H. 
Published: July 2010

The inheritance of three forage quality characters, plant height, three yield characters, and two seed characters was studied in a cross between two inbred lines of sericea, Lespedeza cuneata (Dumont) G. Don. The design included F4 progenies from 3 F3 plants from each of 80 F2 plants and provided estimates of additive (σ2A), dominance (σ2D), and additive by additive (σ2AA) variances.Progeny means for tannin content of forage were bimodally distributed, indicating tannin content to be largely controlled by a partially dominant allele at a single locus. The σ2A component was significantly large in eight of nine characters, σ2D in two, and σ2AA in none. For tannin and three yield traits σ2D was large relative to total genetic variance, and inbreeding depression was noted for these traits. Thus, although inbreeding may be employed to enhance the efficiency of selection for chemical characteristics, it may be necessary to intercross several selected lines in the final stages of the improvement program to restore productivity.Heritability estimates ranged from 45 to 88%, indicating opportunity for progress through selection in all nine characters.
Mechanisms of Strontium Accumulation in Tissues of Wheat Spikes 1
Authors: Craker Lyle E. , Smith Lawrence H. 
Published: July 2010

Studies of strontium accumulation in grain of excised wheat (Triticum aestivum L) spikes indicate that active mechanisms, analogous to those based upon the carrier concept in root absorption studies, mediate this process.No evidence was found to suggest that Sr is passively accumulated in grain. No relationship, between transpiration rate and Sr accumulation in gram was found.
Effects of Loose Smut Infection and Vitavax Seed Treatment on Barley Yields1
Authors: Stoker G. L. , Dewey W. G. 
Published: July 2010

The effect of loose smut caused by Ustilago nuda (Jens.) Rostr. on barley (Hordeum vulgare L.) yields, its control by Vitavax, and the possible direct effect of Vitavax on yields were studied with 10 seedlots of ‘Gem’ barley ranging in infection from .03 to 22%.Yield losses were roughly proportional to percent infection; however, there was a tendency for percent infection to exceed percent yield loss at the higher smut levels. The percentage of loose smut in each of the 10 seedlots was determined by means of the embryo test, as well as by a corresponding field planting. The embryo test appeared to be a good, although a slightly conservative, predictor of field infection.Seed treatment with Vitavax gave 100% control of loose smut over the range of infection tested. The beneficial effect of Vitavax in controlling loose smut was partially offset by an apparent direct adverse effect on yield. At very low levels of infection the yield reduction due to Vitavax treatment exceeded the benefit derived from the smut control. As infection levels rose above 5%, Vitavax treatment increased yields; however this increase did not reach statistical significance until loose smut levels approached 20%. Vitavax‐treated plots had significantly fewer tillers than did untreated plots.