bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breeding Behavior for Crosses of Crambe abyssinica and a Plant Introduction Designated C. hispanica1
Authors: Meier V. D. , Lessman K. J. 
Published: July 2010

Plant selections from PI 247310 (C. abyssinica) and PI 279346 (C. hispanica) were paired randomly and crossed reciprocally. The average seed set from these crosses was about 77% with no reciprocal differences detected. Chromosome counts were made on pollen mother cells from each species and the F1 progeny. The average count was 41 bivalents at diakinesis for each species and the F1 plants; the number could not be counted accurately in every cell, however, because of difficulties in obtaining good smears, the tendency of bivalents to cluster, and small chromosome size. The actual chromosome number is probably 90 (45 bivalents) as previously reported for C. abyssinica. No cells were observed with 60 chromosomes (30 bivalents), which is the number reported for C. hispanica. Data and observations suggest that PI 247310 and PI 279346 should be classified into one species.A normal diploid simple Mendelian ratio was observed for pubescence. The gene controlling pubescence, designated p, segregated 3 glabrous seedlings:1 pubescent seedling, indicating single‐gene control of this character. A total of 6,229 seedlings were observed. Seedlings that were thought to be heterozygous had several hairs at the edges and tips of the older leaves. Nevertheless, these seedlings, indicating partial dominance, were classified as glabrous.Estimates of natural outcrossing were obtained. Crambe appears to be mainly self‐pollinated with an average of 4 to 7% outcrossing among adjacent rows 96 cm apart. Estimates from individual plants ranged as high as 28%. Results indicate that crambe belongs to the often cross‐pollinated group of plants. The estimates are conservative, since crosses to the dominant parent are not detected in the first generation.
Temperature Effects on Hypocotyl Elongation of Soybeans1
Authors: Gilman D. F. , Fehr W. R. , Burris J. S. 
Published: July 2010

Effects of temperature on hypocotyl elongation of soybean [Glycine max (L.) Merr.] cultivars were studied in unlighted growth chambers. We evaluated the relationship between length of exposure to 25 C and amount of inhibition of hypocotyl elongation. Seeds of four cultivars were germinated in sand and in paper towels at each of three temperatures (20, 25, and 30 C), then transferred at daily intervals to a different temperature for the remainder of an 11‐day growth period. Initial → final temperature sequences used were 20 → 25 C, 30 → 25 C, 25 → 20 C, and 25 → 30 C. Hypocotyl lengths of ‘Hawkeye’ seedlings (a long hypocotyl cultivar) were similar in the four temperature regimes. Hypocotyl lengths of ‘Clark,’ ‘Ford,’ and ‘Amsoy’ seedlings (short hypocotyl cultivars) decreased with increased length of exposure to 25 C.The length of exposure to 25 C needed for classification of cultivars was evaluated. Seedlings of Clark, Ford, Amsoy, and Hawkeye were grown at constant temperatures of 20, 25, and 30 C and measured daily up to 10 days after planting. Hypocotyl growth rates of all cultivars were comparable at 20 and 30 C. At 25 C, Hawkeye grew at a faster rate than the other cultivars beginning 3 days after planting, and differences among cultivars increased with days after planting. Differences among cultivars were most fully expressed 10 days after planting.Inhibition of hypocotyl elongation was studied at constant temperatures between 20 and 32 C, at 1‐C increments. Inhibition of short hypocotyl cultivars occurred at all temperatures between 21 and 28 C, with maximum inhibition at 25 C.Our results indicate that the amount of inhibition of hypocotyl elongation is influenced by length of exposure to inhibiting temperatures between 21 and 28 C. This range of inhibiting temperatures permits the use of ordinary laboratory facilities for large‐scale testing of soybean genotypes in a breeding program.
Indirect Mass Selection for Grain Yield in Oat Populations1
Authors: Chandhanamutta P. , Frey K. J. 
Published: July 2010

The effectiveness of mass selection for heavy panicle weight in a heterogeneous oat (Avena sativa L.) population was evaluated using an F6 bulk oat population composed by mixing seed samples from 160 crosses. To initiate the selection procedure, 6,000 samples of 30 seeds were sown, each in a hill in the center of a 0.09‐m2 land area. After harvest, the three heaviest panicles (10%) were selected from each hill and bulk‐threshed. Two cycles, of this type of mass selection were carried out, and subsequently, 390 lines from the original and first cycle mass‐selected populations, 360 lines from the second cycle mass‐selected population, rand 30 check cultivars were tested for grain yield and other traits in replicated experiments.The mass‐selection procedure increased panicle weight 7.5% and grain yield 5.6% per cycle. These shifts were associated with taller plant heights and later heading dates. The increase in grain yield was attributed 80% to increased seeds per panicle and 20% to increased seed weight. Tillering was decreased 2.5%.
Heritability of Oat Caryopsis Percentage and Other Grain Quality Components1
Authors: Wesenberg D. M. , Shands H. L. 
Published: July 2010

Three oat (Avena sativa L.) crosses involving parents with a wide range of caryopsis percentage and other grain quality components were studied in F2, F3, and F4. A single backcross was studied in BCF1 and BCF2. Primary caryopsis percentage of parents averaged 80.3% for ‘Q.O.30.28,’ 77.1% for ‘RL 2123.38,’ 73.1% for ‘Beedee,’ and 71.5% for ‘Coker 61‐13.’Progeny caryopsis percentages were generally within observed parental values with mean values approximating those of the midparents. The mean of the backcross progenies approached the high caryopsis percentage of the recurrent parent.Heritability estimates for primary caryopsis percentage by variance components were high with the exception of Q.O.30.28/RL 2123.38 where both parents were high in caryopsis percentage. Heritability estimates ranged from 0.36 for Q.O.30.28/RL 2123.38 to 0.93 for Q.O.30.28/Coker 61‐13. Estimates of genetic advance ranged from 0.51 to 3.95%, suggesting that increases above midparent and near high parent values could be attained by selecting for high caryopsis percentage. The data suggest difficulty in isolating segregates with more than 80% caryopsis.
Influence of Succinic Acid 2,2‐Dimethylhydrazide on Yield and Morphological Characteristics of Starr Peanuts (Arachis hypogaea L.)1
Authors: Brown R. H. , Ethredge W. J. , King J. W. 
Published: July 2010

Succinic acid 2,2‐dimethylhydrazide (SADH) was applied to “Starr” peanuts (Arachis hypogaea L.) at the rate of 1.43 kg/ha in 1968, 1969, and 1970. Data were obtained on pod yield; stem length; peg and pod lengths; pod, stem and leaf weights; and leaflet area. The most consistent effect of SADH was a reduction of plant height. Stem lengths were reduced 30 to 40% by SADH application. Pod length was reduced by 6 to 10% in 1969 and 4% in 1970 when plants were treated with SADH. Peg length in 1970 was 2.7 cm on SADH‐treated plants compared to 3.4 cm for controls.Pod yields were increased in 1968, but not in 1969 or 1970. The increase in yield in 1968 was similar for irrigated and nonirrigated peanuts. Stem weight per plant was decreased by SADH in 1970 but not in 1969, and the pod‐vegetative ratio was increased in 1969 and 1970. Specific leaf area and area of leaflets were reduced in some cases by SADH applications. Dry weight per leaflet was not affected. Reduction of top growth may be beneficial because ground machinery can be used later than usual in the season to apply insecticides and fungicides without damage to the peanut plants.
Plant‐Water Measurements on Soybeans Sheltered by Temporary Corn Windbreaks1
Authors: Radke J. K. , Hagstrom R. T. 
Published: July 2010

Double rows of corn (Zea mays L.) spaced at regular intervals in a soybean (Glycine max (L.) Merr.) field served as temporary windbreaks at two locations in western Minnesota. In 1969 at Dumont, Minnesota, corn windbreaks were placed between every 14 rows of soybeans (every 11.4 meters), and in 1970 at Lamberton, Minnesota, 22 rows of soybeans (17.5 meters) separated the corn windbreaks. Moisture stress was high in 1969, but moisture was adequate in 1970.Small, white evaporimeters provided estimates of potential evaporation, soybean plant potometers furnished information on potential transpiration, and the stomatal resistances of the soybean leaves were measured by a porometer and from leaf impressions. Windspeed and potential evaporation were reduced significantly over the first seven or eight soybean rows on the lee side of the windbreaks. Potential transpiration and stomatal resistance varied significantly among rows between corn windbreaks and in some cases showed cyclic trends over rows. Potential transpiration and stomatal resistance appeared to be directly related when moisture stress was low, but were inversely related when moisture stress was high.Sheltered soybean yield increases and variations over rows were largely an accumulation of the variations that occurred in the plant‐water relations during the growing season.
Breeding for Soybean Hypocotyl Length at 25 C1
Authors: Fehr W. R. 
Published: July 2010

The effectiveness of breeding for soybean (Glycine max (L.) Merr.) hypocotyl length at 25 C was evaluated by examining segregation from crosses between long, intermediate, and short hypocotyl cultivars and performance of the parent cultivars. Progeny were evaluated in F1 and F2 as individual seedlings and in F3 as the mean of 24 seedlings for each F2 line. All tests for hypocotyl length were conducted in the dark in growth chambers maintained at 25 ± 1 C.Evaluation of individual seedlings for the parent cultivars indicated that there was an environmental influence on hypocotyl length, particularly for the intermediate cultivars. There was little overlap in the single plant distributions for long and short hypocotyl cultivars, but the distributions for intermediate cultivars had considerable overlap.Progeny from crosses between long hypocotyl cultivars were similar to the parents in hypocotyl length. Crosses of long ✕ intermediate and long ✕ short parents had segregation typical of a major gene with dominance for long hypocotyls. The F2 lines in F3 generally were within the range of the parents for intermediate ✕ intermediate, intermediate ✕ short, and short ✕ short crosses.Selection for genetic differences in hypocotyl length at 25 C is possible. To select for long hypocotyl genotypes, crosses should include at least one long hypocotyl parent. In crosses involving only intermediate and short hypocotyl parents, transgressive segregates may be found that exceed the length of the best parent; however, the frequency of superior segregates in such crosses probably will be low.Selection for hypocotyl length on a single plant basis is hampered by environmental effects. In a segregating population, selection for long hypocotyl genotypes on a single plant basis will eliminate many of the short hypocotyl genotypes, but will include some of the intermediate genotypes. A progeny test is the best way to evaluate a genotype's genetic potential for hypocotyl length.
Cytology of Obligate Sexual Plants in Panicum maximum Jacq. and Their Use in Controlled Hybrids1
Authors: Hanna Wayne W. , Powell Jerrel B. , Millot Juan C. , Burton Glenn W. 
Published: July 2010

We isolated 18 obligate sexual plants of guineagrass (Panicum maximum Jacq.) from 2 plant introductions, PI 277922 and PI 277946, by analysis of morphological variation and cytological studies. Megasporogenesis and embryo sac development was typical of the Gramineae family. Sixteen controlled crosses involving 10 sexual plants ✕ robust short day apomictic plants produced 156 progenies. Fifty‐nine of the progenies were hybrids.The inheritance data, based upon progeny of selfed sexual plants and sexual ✕ apomictic hybrids indicated that sexuality is dominant. Sexuality appears to be controlled by at least two loci and conditioned by a dosage effect of two or more dominant alleles.This research demonstrates that it is possible to release the “stored” variability in this apomictic species through controlled sexual ✕ apomictic hybrids.
Analysis of Several Morphological Traits and Their Associations with Digestibility in Bromus inermis Leyss.1
Authors: Sleper D.A. , Drolsom P.N. 
Published: July 2010

Several morphological traits were examined in smooth bromegrass (Bromus inermis Leyss.) Significant differences were found among genotypes for leaf length, leaf width, culm diameter, plant height, and plant color. General combining ability was significant at the 1% level for leaf width, culm diameter, and plant color. Specific combining ability was significant at the 5% level for leaf length and plant height.Leaf width, culm diameter, and dark green color were associated positively, and plant height negatively, with acid‐pepsin dry matter disappearance.
Antitranspirant Action of Carbon Dioxide on Intact Sorghum Plants
Authors: van Bavel C. H. M. 
Published: July 2010

Twenty‐day‐old hybrid sorghum (Sorghum bicolor (L.) Moench) plants of the ‘Oro’ variety were grown in a closely controlled environment in which the air temperature was 30 C, the humidity about 80%, the horizontal air flow about 1 m s−1, and the incident, photosynthetically active radiation close to the maximum daylight level in clear weather. The ambient carbon dioxide level was varied to induce varying degrees of stomatal aperture and internal levels of carbon dioxide. This manipulation affected transpiration and carbon assimilation simultaneously, decreasing the former and increasing the latter.The results were compared with a mathematical model of leaf action in which assumptions had to be made as to the mathematical form of the relations and the value of the constants. The effect of the carbon dioxide level upon stomatal aperture was well predicted by the model, as originally conceived, regarding both the nature of the functional relation and the value of the constant required.
Nitrate Reductase Activity in Sudangrass Cultivars1
Authors: Eck H. V. , Hageman R. H. 
Published: July 2010

Seventeen sudangrass [Sorghum sudanense (Piper) Stapf] varieties and sudangrass‐sorghum (Sorghum color L. Moench) crosses were evaluated for nitrate reductase activity by both in vitro and in vivo procedures. They were also evaluated for total cyanide concentration. Measurements were made on leaf tissue of 10‐, 14‐, and 18‐day‐old growth chamber‐grown seedlings. Nitrate reductase activity ranged from 9.6 to 3.3 µmoles NO−2.g fresh wt−1.hr−1 for the in vitro assay and from 3.9 to 0.8 µmoles NO−2.g fresh wt−l.hr−1 for the in vivo assay. Significant differences in nitrate reductase activity among genotypes were detected by both assays. While the in vivo activity was only 30% that of the in vitro assay, the range and relative rankings of the genotypes were similar as shown by the overall correlation, r = 0.6 (significant at the 1% level). Total cyanide concentration in the leaf tissue ranged from 16.4 to 1.5 µmoles.g fresh wt−1 and significant differences were noted among the 17 genotypes. Both nitrate reductase activity and cyanide concentration decreased with plant age.Maximum recovery of nitrate reductase activity was obtained with an extraction medium containing 20 mM gluthathione and 4 mM NiCl2 The optimum tissue: extraction medium ratio was 1:20. The NiCl2 protected nitrate reductase from exogenous cyanide up to 7.2 µmoles/g, which is higher than is likely to be produced in the extracts by hydrolysis of the cyanogenic glucoside found in sudangrass.
Growth and Productivity of Cotton Grown from Seed Produced Under Four Night Temperatures1
Authors: Quisenberry J. E. , Gipson J. R. 
Published: July 2010

The seeds used in this study were produced by growing cotton (Gossypium hirsutum L.) plants from first flower through boll maturation in growth chambers where tire night temperatures were 11, 15, 21, and 27 C. These seeds were used to evaluate the effect of seed quality on the growth and productivity of matured plants. The cultivars used were ‘Acala 1517 Br2,’ ‘Stoneville 7A,’ ‘Lankart Sel 57,’ ‘Stripper 31,’ and ‘CA 491.’ Characters or traits measured were 1) seed weight and percentage of germination of the seed produced in the temperature controlled growth chambers; and 2) rate of seedling emergence, vegetative growth rates, seed cotton per plant, bolls per plant, and production rate index of the plants grown from the seed produced in the chambers.Low night temperatures during the seed maturation period had a detrimental effect upon seed quality (seed weight and percentage of germination). In field plantings, seedlings from seeds produced under low night temperatures (11 and 15 C) emerged more slowly than those from seeds produced under high night temperatures (21 and 27 C). The plants that developed from seeds produced under low night temperatures (11 C) grew more slowly and were less productive than plants from seeds produced under high night temperatures (21 and 27 C).
Effect of Normal Cytoplasms on Resistance to Southern Corn Leaf Blight and on Other Traits of Maize1
Authors: Good R. L. , Horner E. S. 
Published: July 2010

Maize (Zea mays L.) hybrids having Texas male‐sterile cytoplasm are much more susceptible to Race T of Helminthosporium maydis Nisikado and Miyake than normal cytoplasm hybrids. This has raised questions about the effects of different normal cytoplasms on resistance to Race O of H. maydis.We evaluated 222 reciprocal plant‐to‐plant crosses, involving 60 diverse germplasm sources, in a 3‐stage series of tests for cytoplasmic effects on susceptibility to H. maydis and other traits. F2 and F3 crosses were used in the second and third stages, respectively, to eliminate maternal seed effects. The crosses were subjected to both Race O and Race T of H. maydis.In the second stage of testing one cross was found to have an appreciable reciprocal effect on susceptibility to H. maydis. This cross, along with several others, also showed significant reciprocal differences for such traits as height, maturity, and yield. However, when the three crosses having the largest differences between reciprocals were retested using fresh seed, the differences observed the previous year were not found. We conclude that many, if not all of the apparently significant differences found in the second stage of testing were due to sampling variation or maternal seed effects, and that the normal maize cytoplasms we tested had no measurable effect on susceptibility to H. maydis or on several other traits.
Morphological and Anatomical Features of Alfalfa Leaves as Related to CO2 Exchange1
Authors: Delaney R. H. , Dobrenz A. K. 
Published: July 2010

Cuttings from alfalfa (Medicago sativa L. cv. ‘Mesa‐Sirsa’) genotypes which exhibited a wide range in leaflet size were grown under spaced‐planted and nonspaced‐planted conditions and used to determine the relation. ships between leaflet anatomy, leaflet morphology, and CO2 exchange. These same relationships were evaluated under controlled environmental conditions using alfalfa population MSE‐6 which has a broad germplasm base.Area per leaflet and leaflet width were negatively associated with photosynthetic rate per unit leaf area. Specific leaf weight (SLW) was positively correlated with photosynthesis; however, the correlation coefficients were consistently lower than the r values for leaflet size vs photosynthesis. Photosynthesis expressed as total CO2 uptake per plant was not significantly associated with SLW and leaflet size. Plants with small leaves had the greatest SLW, palisade tissue thickness, and leaf thickness. A positive association was observed between palisade tissue thickness and photosynthesis expressed on a leaf area basis. The significance of leaflet size as a selection tool for photosynthetic rate in alfalfa is discussed.
Changes in Free Proline Concentration in Sorghum and Soybean Plants Under Field Conditions1
Authors: Waldren R. P. , Teare I. D. , Ehler S. W. 
Published: July 2010

Free proline in the leaves of sorghum [Sorghum bicolor (L.) Moench cv. ‘Pioneer 846’] and soybean [Glycine max (L.) cv. ‘Calland’] was measured in the field under drought stress and adequate soil moisture. Leaf water potential and stomatal diffusive resistance were the measures of drought stress in the plants.Free leaf proline in nonstressed plants changed during the day but seasonal changes were insignificant. Free proline increased with light intensity and varied widely in middle leaves that were shaded or received sunlight. Free proline did not accumulate significantly until plants were severely stressed and visibly wilting (about −20 bars leaf water potential in soybean). Variation was high in both stressed and nonstressed plants. However, factors that affected transpiration demand also affected free proline accumulation.For irrigation scheduling free proline was not a good indicator of drought stress in the field because it increased after the critical time to irrigate for maximum yield.
Flat‐Square in Cotton, Acala Type. I. Its Mode of Inheritance and Heritability1
Authors: Khalifa H. , Starmer W. T. , Fisher W. D. , Stith L. S. 
Published: July 2010

Flat‐square, an unidentified flower disorder in cotton (Gossypium hirsutum L.) which is manifested at bloom time, appeared on a large scale in Arizona during 1962. Part of this study was designed to verify the mode of inheritance and heritability of this disorder.Three homozygous inbred lines of Acala‐type cotton known to exhibit flat‐square were intercrossed with a doubled haploid line free from flat‐square. Seeds of the F1, F2, BCDf, and BCf generations were grown simultaneously with the parental populations to evaluate its mode of inheritance and heritability.Flat‐square was found to be quantitatively inherited, with low heritability. The estimates of the genetic parameters indicate that the inhertance is mostly additive in nature with no evidence of epistasis or maternal effect.
Effect of Row Spacing and Genotypic Frequency on the Yield of Soybean Blends1
Authors: Fehr W. R. , Rodriguez S. R. 
Published: July 2010

The effects of row spacing and genotypic frequency on the yield of soybean (Glycine max (L.) Merr.) blends were evaluated for use in establishing testing procedures for new blends. In 1969 and 1970, ‘Chippewa 64,’ ‘Hark,’ ‘Corsoy,’ ‘Provar,’ and ‘Amsoy’ were evaluated in all possible two‐component blends at the frequencies 3:1, 1:1, and 1:3, and in all possible three‐component blends in a 1:1:1 frequency. The blends and pure stands were tested for yield in 70‐ and 100‐cm rows.The average yield response of blends to narrow rows was similar to that of pure cultivars. The average yield increase in 70‐cm rows over 100‐cm rows was 9.6% for the two‐component blends, 10.2% for the three‐component blends, and 10.0% for the cultivars in pure stand.Average compensatory responses (deviations of actual blend yields from the weighted means of their component cultivars in pure stand) were similar for both spacings. The average compensatory response was 69 kg/ha or 2.5% for 100‐cm rows and 72 kg/ha or 2.4% for 70‐cm rows.Although row spacing generally did not influence compensatory responses, there were blends that had significant deviations from the expected yield in one spacing but not in the other. Furthermore, the percentage yield differences in two row spacings for a blend could not be consistently estimated from the percentage row‐spacing response of its component cultivars. It seems that whenever possible, the compensatory response of a blend and its yield response to different row spacings should be evaluated by testing the blend per se in the row spacings of interest.In 1971 and 1972, genotypic frequencies in four two‐component blends were varied in 10% increments from 100:0 to 0:100. Compensatory responses of the blends were found to be dependent on genotypic frequency. Maximum yields of the blends generally occurred over a limited range of genotypic frequencies. All blends had their highest yields when the highest yielding cultivar made up at least 70% of the blend.