bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transgressive Segregation and the Nature of Gene Action for Yield in an Intervarietal Cross of Upland Cotton1
Authors: El‐Adl A. M. , Miller P. A. 
Published: July 2010

Two inbred parental lines, their F1, and six inbred lines selected for high yield after three cycles of recurrent selection in this population were evaluated at three locations for two years. The F2 yielded 32.6% more than the midparent value and exceeded the higher parent by 13.3%. The F1 also exceeded the midparent values for several components of yield, including lint percentage, weight per boll, number of bolls per plot, lint index, and seed index.The mean yield of the six selected lines exceeded that of the F1 by 5.5%. Each of the six lines was higher in lint yield and lint percentage than the higher parent of the original cross, which indicated that transgressive segregation for these traits had occurred.Fifteen possible crosses among the six lines were compared with the above entries at three locations in the second year. These hybrids averaged 9.6% higher in yield than the mean of their parents. Significant heterosis was also detected for lint percentage, weight per boll, number of seed per boll, and lint index.Estimates of general combining ability from the set of diallel crosses were significant for all traits except lint percentage, which demonstrated the importance of additive genetic effects for those traits. The variance for specific combining ability was significant only for lint percentage.
Recovery of the Recurrent Parent Phenotype During Backcrossing in Soybeans1
Authors: Wilcox J. R. , Probst A. H. , Athow K. L. , Laviolette F. A. 
Published: July 2010

Soybean [Glycine max (L.) Merr.] lines resistant and susceptible to Phytophthora megasperma Drechs. var. sojae A. A. Hildeb., selected in successive backcross generations, were evaluated for maturity, height, lodging, seed size, yield, and oil and protein content. Recovery of the phenotype of the recurrent parent was generally slower than predicted, assuming only additive genetic control of agronomic characteristics. Deviations from predicted performance were probably due to continued segregation for genes controlling the expression of these characteristics and the limited sample (4 to 8 lines) used to evaulate each generation.Resistant selections were 3 to 6 cm taller and lodged more than susceptible selections. The shorter plant height of susceptible selections may be due to insidious infection. The increase in lodging of resistant selections may be a reflection of increased plant height or vigor due to resistance.Implications of these results on backcross breeding of soybeans are discussed.
Breeding Hard‐Seeded Vetch Using Interspecific Hybridization1
Authors: Donnelly E. D. 
Published: July 2010

SummaryVicia sativa L. (2n = 12) and V. cordata Wulf. (2n = 10) were crossed to incorporate the gene or genes for hard seed from the latter parent into an agronomically desirable V. sativa line. The F1 was highly infertile. The F2 and succeeding generations segregated for parental and recombination types, fertility, and permeability of seedcoat. In each generation selection for hard seed resulted in an increase in frequency of plants that produced 70 to 100% hard seed. Hardseededness increased from 9% in the F2 to almost 90% in the F5 and F6. Fertility and vigor were restored in the V. sativa type by F4. Recombination types continued to segregate for percentage hard seed, plant type, and seed production through F6. V. cordata types were not selected beyond the F3 because of the small size of this parent. Many V. sativa type F6 lines were genetically stable for a high percentage hard seed and high seed yield.
Leaf Area, Dry‐Matter Production, and Carbohydrate Reserve Levels of Birdsfoot Trefoil as Influenced by Cutting Height1
Authors: Greub L. J. , Wedin W. F. 
Published: July 2010

The effects of three cutting heights on residual leaf area index (LAI), leaf area development, leaf efficiency (LE), mean crop growth rate (CGR), dry‐matter (DM) yield, and total nonstructural carbohydrates (TNC) were studied in 1‐year‐old stands of birdsfoot trefoil (Lotus corniculatus L., cultivar ‘Empire’) in 1965 and 1966. Data were taken during an early and a late‐summer regrowth period, each of 7 weeks in length.The 3.8‐, 7.6‐, and 11.4‐cm cutting heights resulted in minimum effective LAI values of 0.05, 0.37, and 1.10, respectively, for the early summer regrowth. After 7 weeks the net DM yields of the 7.6‐ and the 11.4‐cm treatments were similar and significantly greater than those of the 3.8‐cm treatment. The 3.8‐cm treatment removed leaf area and axillary bud sites, thereby retarding initial regrowth and leaf development. Root and crown diseases were increased in late summer by the 3.8‐cm treatment. The LE increased as stubble height decreased, and decreased over time in all treatments. The CGR values increased with increased cutting height during the first 3 weeks of early summer regrowth. Thereafter, and during the late‐summer regrowth, there was considerable week‐to‐week variation in the CGR. Except for TNC and LE, the late‐summer responses were generally similar to those for early summer, but the values were less.TNC levels increased as residual LAI increased during both regrowth periods. In early summer the differences were small and had nearly disappeared by the 7th week. In late summer the differences were greater than those for early summer and persisted throughout the 7 weeks.
Cotton (Gossypium birsutum L.) Yield, Stand, and Bolls per Plant as Influenced by Seed Class and Row Width1
Authors: Peacock H. A. , Reid J. T. , Hawkins B. S. 
Published: July 2010

Unsorted seed of ‘Deltapine 45A’ and seed separated into almost equal lots of light, medium, and heavy seed (seed classes) were planted in 102‐cm (regular) and 25‐cm (narrow) rows (row widths) at the rate of six seed per 30.5 cm.Plants from the light seed class were taller 75 days after emergence than were plants from any other seed class regardless of row width. Lint yield was not affected by row width or seed classs. The interaction between row widths and seed classes was significant and, in regular‐width rows, plants from unsorted seed produced more lint than did plants from the heavy seed class.Unsorted seed produced more barren plants than did other seed classes. This result was apparently due to the larger number of plants produced from the unsorted seed in narrow rows.Unsorted, light, and medium seed classes produced more 1‐boll plants than did the heavy seed class. As plant population increased, there was an increase in the number of 1‐boll plants. Seed class had no effect on the number of 2‐boll plants; however, regular‐width rows produced significantly more 2‐boll plants than did narrow rows. The medium seed class produced fewer 3‐boll plants than other seed classes regardless of row width, and regular‐width rows produced more 3‐boll plants than did narrow rows. Due to an interaction between row width and seed class, unsorted seed produced more 3‐boll plants than the light, medium, or heavy seed class in regular‐width rows. Seed planted in regular‐width rows produced more plants with more than three bolls than in narrow rows. Under the conditions of this test there were no advantages from either seed sorting or narrow rows.
Expression of Heterosis in Sericea Lespedeza with Competitive vs Noncompetitive Plant Spacing1
Authors: Cope Will A. 
Published: July 2010

SummaryOpen‐pollinated and self progenies of 10 inbred lines of sericea, Lespedeza cuneata (Dumont) G. Don, were grown at both wide, noncompetitive, and close, competitive, spacings. The objective was to compare estimates of heterosis for the different levels of plant competition. Plant height was measured 6 weeks after transplanting, and yields of forage and seed were taken for 2 years. The 10 inbred lines were quite different in respect to height and forage and seed production. Heterosis was estimated as the percentage by which open‐pollinated progenies of these lines exceeded self progenies within a given spacing. Average values of heterosis at close spacing greatly exceeded those at wide spacing for forage and seed yields. Estimates ranged from 4 to 18% for wide spacing and from 8 to 64% for close. The less‐vigorous inbred lines, and particularly their self progenies, tended to be suppressed at the close spacing. Combining ability for vigor was expressed to a greater degree at the close spacing, a competitive condition much more like farm conditions than the spaced‐plant nurseries of the plant breeder. The sericea breeder should be aware of the importance of progeny testing under close spacing to more accurately characterize vigor of breeding lines.
Quantitative Inheritance of Some Head and Seed Characteristics in Sorghum [Sorghum bicolor (L.) Moench]1
Authors: Fanous Mamdouh A. , Weibel Dale E. , Morrison Robert D. 
Published: July 2010

Heritabilities and expected genetic advances were estimated for head length, seed‐branch length, node number per head, and 100‐seed weight in five crosses of sorghum [Sorghum bicolor (L.) Moench]. Phenotypic, genotypic, and environmental correlation coefficients also were calculated.Head length and seed‐branch length exhibited relatively large estimates of heritability and expected genetic advance in each cross. In general, high positive genotypic correlations were observed between these characters. Therefore, rapid progress should result from early generation slection for either character, which should also result in simultaneous improvement in the other character as well.Node number per head and 100‐seed weight exhibited relatively low heritabilities and expected genetic advances. Substantial progress under early generation selection for these characters could not be expected. However, selection for longer heads should increase node number per head in four of the five crosses and 100‐seed weight in one cross, since high positive genotypic correlations were observed in those instances.
Growth Studies of the Sugarcane Plant. II. Some Effects of Root Temperature and Gibberellic Acid and Their Interactions on Growth1
Authors: Mongelard J. C. , Mimura L. 
Published: July 2010

Three‐month‐old sugarcane (Saccharum officinarum) plants were raised from single‐eye cuttings and grown in aerated nutrient solution for an additional 28 days at an air temperature fluctuating between 21.5 C (night) and 30.5 C (day). The nutrient solutions in which the roots were immersed were kept at eight different temperatures ranging from 12.5 C to 33.5 C. Half the number of plants in each temperature treatment were treated weekly with gibberellic acid (GA). The GA (100 µg) was applied in 0.1 ml of water per plant in the folded leaves above the top visible dewlap.A loss in mean dry weight of the plants at a root temperature of 12.5 C indicated a higher respiratory than photosynthetic activity. Above 15.5 C an increase in root temperature resulted in an almost linear increase in dry matter production up to 30.5 C. The effect of GA on dry matter production was more pronounced at 18.5 C than at 27.5 C to 30.5 C. There was very little response to GA application at intermediate temperatures. Tiller production was reduced by root temperature below 24.5 C, above which there was an increase in the mean number and mean dry weight of tillers with increasing temperature. GA caused a reduction in tiller dry weight at 27.5 C; however, the effect decreased above that temperature.It is suggested that GA production in the roots, or translocation from the roots, or both, are inhibited by root temperatures below 18.5 C, which would explain the high response to applied GA at 18.5 C. At temperatures of 27.5 C and 30.5 C a positive response to exogenous GA might be the result of depletion, through consumption of endogenous GA due to the rapid growth rate of the plants at these temperatures. The growth of the GA‐treated plants was maximum at a root temperature of 30.5 C under the conditions of the experiment. for the control plants maximum growth was attained at the root temperature of 33.5 C. However, the maximum response to GA, compared to the controls at the same temperature, occured at 18.5 C.
Development and Performance of Double‐Cross Hybrid Red Clover1
Authors: Anderson M. K. , Taylor N. L. , Kirthavip R. 
Published: July 2010

Genetic control of crossing was accomplished by using inbreds with homozygous S‐alleles to produce double‐cross hybrid red clover (Trifolium pratense L.). The method, checked by the use of the leafmark gene, proved to be effective in controlling crosses for the production of hybrids. Single and double crosses were evaluated for performance. Certain I1 single and double crosses showed consistently good performance in all characters studied, but most were not superior to the best check variety.Significant correlations were observed between characters evaluated in spaced plantings and broadcast plots, indicating that spaced plantings can be used effectively in the preliminary selection of superior single and double crosses.
Combining Ability in Alfalfa Hybrids Made with Cytoplasmic Male Sterility1
Authors: Pedersen M. W. , Hill R. R. 
Published: July 2010

Seventy alfalfa (Medicago sativa L.) hybrids were produced by crossing l0 cytoplasmic male‐sterile parents with 7 untested male parents. Variance components due to males, σ2M, females, σ2F, and their interactions, σ2MF, were estimated for yield during two growing seasons and for pollen production in one season.Variance components, σ2F and σ2MF, were more important than σ2M for yield in the year of establishment. Components, σ2M and σ2F, were approximately equal, and σ2MF was unimportant for yield in the second growing season. The only important component of variance for pollen production was σ2M. The greater importance of σ2F and σ2MF in the year of establishment was attributed to a correlation between seed weight and yield. The small value of σ2MF after the year of establishment indicated that parents could be selected for general combining ability without testing numerous specific combinations. Correlations between pollen production and forage yield were very small and nonsignificant, indicating that male fertility would not have to be restored in alfalfa hybrids used for forage production.
Effects of Varying Root/Shoot Temperatures on Early Growth of Subterranean Clover1
Authors: Summer D. C. , Raguse C. A. , Taggard K. L. 
Published: July 2010

We sought to determine the individual contributions of ambient root and shoot temperatures to rate of plant development, dry matter accumulation, and root/shoot ratio. Subterranean clover (Trifolium subterraneum L., subsp. yaminnicum Katznelson and Morley)' plants were grown from seed to the 7‐ to 10‐ leaf stage in sand‐nutrient culture. Combinations of 10 and 20 C were used in the following basic chronological sequence: (i) plants were grown at 20 C from seed to the two‐leaf stage; (ii) root, shoot, or overall temperature was then lowered to 10 C and growth was allowed to progress until the five‐leaf stage; and (iii) temperature was returned to 20 C and growth was continued to the 7‐ to 10‐ leaf stage.Growth was expressed as a regression of trifoliolate leaf number on days accumulated (y = bx + a) within each of the three growth intervals. For intervals (i) and (iii), b = 0.32 and 0.44, respectively. For (ii), b = 0.20 (root temp. 10 C), and 0.15 (overall temp. 10 C). Correlations (rxy) = 0.99 in all instances. Plant weights were more closely related to final stage of plant development than to temperature treatment. Root/shoot ratios averaged 0.44. Shoot ambient temperature appeared to be less important than root ambient temperature as a determinant of growth rate.
Changes in Nonstructural Carbohydrate Fractions at Intervals Down the Tap Root Bark and Wood of Alfalfa (Medicago sativa L.) During Regrowth1
Authors: Escalada J.A. , Smith Dale 
Published: July 2010

Changes in total nonstructural carbohydrates (TNC) at intervals down the tap root of alfalfa (Medicago sativa L.) during regrowth were studied to determine what depth of root sampling would adequately reflect readily available carbohydrate trends during regrowth. After the tops were harvested in mid‐August, alfalfa roots were dug from the soil at weekly intervals to a 30‐cm depth. Tap roots were cut into six segments of 5‐cm length each, separated into bark and wood tissues, and dried at 70 C. Wood made up more of each tap root segment than bark, but ratio of bark to wood increased down the root. Content (grams) of carbohydrate fractions in the segments gave a clearer picture of changes down the root, and with time, than concentration (percentages). About 63% of the TNC used between 0 day and the date of lowest carbohydrate level during regrowth came from the root wood, while only 37% came from the root bark. Starch (ST) content accounted for 62% of the TNC used; 38% was total sugars (TS). About 38% of the TNC content came from the top 5‐cm segment and 23, 16, 10, 6, and 770 came from segments 2, 3, 4, 5, and 6, respectively. About 5S7, of the net gain in TNC content was accumulated in the root wood between the date of lowest carbohydrate level and 47 days, while 42% was accumulated in the root bark. ST content accounted for 88% of the TNC content accumulated; 12% was TS. About 34% of the TNC content accumulated was in the top 5‐cm segment and 22, 15, 12, 9, and 8% could be found in segments 2, 3, 4, 5, and 6, respectively.Loss or gain of weight by each root tissue was almost equal to that of TNC. TNC trends were similar for each root segment, indicating that any depth of root sampling will adequately reflect carbohydrate changes during regrowth.
Fertility and Inbreeding Studies of Cicer Milkvetch (Astragalus cicer L.)1
Authors: Scheetz J.G. , Carleton A.E. , Stroh J.R. 
Published: July 2010

Estimates of cross‐ and self‐fertility were made on 34 cicer milkvetch (Astragalus cicer L.) clones in 1970. Crossfertility was estimated by measuring seed set under openpollination, and self‐fertility was estimated by measuring seed set both from selfing in isolation by native bees and selfing by hand. Seed obtained from four clones were seeded in flats In the greenhouse to study the effect of inbreeding on seedling growth.Cicer flowers were most fertile during the first 3 weeks of flowering. Self‐fertility, estimated by pods‐per‐available‐flowers of all cicer milkvetch clones was 9.8% following self‐pollination by hand. Self‐fertility of four clones under spatial isolation was 58.9% pods‐per‐availableflowers. Cross‐fertility of all clones under open‐pollination was 61.4%. Bees were more effective in achieving selffertilization than hand manipulation. Selfing reduced the growth of cicer seedlings by 32%. Cicer milkvetch is naturally cross‐pollinated with a relatively high degree of self‐fertility when there is no cross‐pollen available and pollination is done by natural pollinators.
Flower Color Inheritance of Crimson Clover (Trifolium incarnatum)1
Authors: Sullivan S. L. , Knight W. E. , Baetcke Karl P. 
Published: July 2010

Crimson, deep pink, and medium pink crimson clover (Trifolium incarnatum L.) flower colors are under the control of gene Cr. There are possibly three alleles of this gene, Cr, Cr′, and Cr′, each one causing a successive increase in total pigment concentration, which in turn determines the precise shade of coloration. All three alleles are dominant to the recessive cr, which results in white color in the homozygous recessive condition.In addition to gene Cr, maroon flowers are also under the control of gene M. The interaction of these two genes results in a 9:3:4 F2 segregation ratio. It is possible that sectoring and incompatibility alleles are involved in these lines.Lavender flower is under the control of two genes, Cr and B. Gene B regulates flavonoid production at the expense of anthocyanin production, resulting in the copigmentation phenomenon that produces the lavender coloration.
Development of Maize Weevil on Kernels of Opaque‐2 and Floury‐2, Nearly Isogenic Corn Inbred Lines1
Authors: Schoonhoven A. V. , Wassom C. E. , Horber E. 
Published: July 2010

Five nearly isogenic inbred lines of corn (Zea mays L.) differing in opaque‐2 or floury‐2 genes were exposed to the maize weevil (Sitophilus zeamais M.). Equal numbers of weevil progeny were obtained from the soft‐endosperm, high‐lysine kernels and from their normal counterparts. The inbred lines yielded significantly different numbers of weevil progeny. Interactions between endosperm types and inbred lines were significant (P<.01). Progeny weevils emerged significantly sooner from highlysine (soft starch endosperm) than from normal endosperm. Weevil developmental periods also differed significantly among the five inbred lines tested.Weights of weevil progeny upon emergence from different inbred lines differed significantly but endosperm character had no influence. Relative influence of seed hardness on weevil progeny and possible effects on storage of high‐lysine corn are discussed.
Estimation of Combining Ability, Hybrid Vigor, and Gene Action for Protein in Avena spp. L.1
Authors: Ohm H. W. , Patterson F. L. 
Published: July 2010

Six Avena sterilis L. introductions, all high in groat protein, were crossed as paternal parents to five A. saliva L. commercial genotypes to estimate combining ability, hybrid vigor, types of genetic effects, and heritability for percent groat protein and protein yield.F1 hybrids produced a lower percent groat protein than the midparental value. Percent groat protein was maintained from F1 to F2. Contrastingly, a large amount of hybrid vigor existed for protein yield in the F1 but was reduced in F2. General combining ability was highly significant for percent groat protein in paternal and in maternal parental groups. Paternal ✕ maternal interaction effects were generally nonsignificant. Each of the A. sterilis parents appeared to have similar proportions of dominant and recessive genes for percent groat protein when in combination with the given set of A. sativa genotypes Partial dominance for low protein was usually indicated. High percent groat protein was recessive in all crosses. Percent groat protein was highly heritable. Protein yield, dependent on seed yield, had low heritability values. Percent groat protein tended to be negatively correlated with seed yield, although the correlation was low and nonsignificant.
Effects of Temperature and Photoperiod on a Virescent Mutant in Smooth Bromegrass1
Authors: Dunn G. M. , Ketel E. J. , Routley D. G. , Couture R. M. 
Published: July 2010

Two growth chamber trials were conducted to determine effects of temperature and photoperiod on the phenotypic expression of a vireseent mutant of Bromus inermis. Maximum expression of the mutant occurred at low‐temperature short‐photoperiod, with a range in percent greening from about 17 for this treatment to 58 at high‐temperature long‐photoperiod. Significant differences were obtained for both temperature and photoperiod. At a constant 12‐hr photoperiod, temperature alone produced highly significant differences, with percent greening being approximately 83% at 27 C, 46% at 21 C, and 16% at 16 C.Four vireseent, one yellow, and one normal green clone were analyzed for chlorophyll at four dates in the spring. Considerable variation was found in total chlorophyll and in rate of greening of the mutant clones in the field, but all except the yellow mutant contained approximately normal amounts of chlorophyll by June 13. Mutant and normal plants were etiolated in the dark, then analyzed for protochlorohpyll and carotenoid pigments. The mutants synthesized approximately as much protochlorophyll as normal plants. Carotenoid pigments were quite low in etiolated mutant seedlings, suggesting a possible genetic block in their synthesis rather than in chlorophyll.