bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inheritance of a Fertility Enhancer Factor from Pima Cotton when Transferred into Upland Cotton with Gossypium Harknessii Brandegee Cytoplasm1
Authors: Sheetz R. H. , Weaver J. B. 
Published: July 2010

Present efforts towards the development of hybrid cotton in the United States are concentrated almost exclusively on the use of Gossypium harknessii Brandegee derived cytoplasmic male sterility. Fertility restoration is controlled by an incompletely dominant gene, leading to variable fertility in heterozygous F1 upland ✕ upland hybrid populations. However, G. barbadense L. apparently possesses a modifying gene(s) which enhances fertility expression when present in upland cytoplasmic malesterile ✕ upland restorer F1 hybrids.Self‐pollinated seed, derived from a cross of male‐fertile plants of G. hirsutum L. in G. harknessii cytoplasm ✕ ‘Pima S‐4’ (G. barbademe), followed by three backcrosses to non‐restoring upland strains was planted in progeny rows in 1977. Individual fertile plants were selfed and testcrossed to six G. harknessii‐derived cytoplasmic male‐sterile strains to determine inheritance of the Pima enhancer factor. Testcrossed and selfed seed were planted in individual progeny rows in 1978 and segregation ratios analyzed.Analysis of progenies showed that male fertility restoration in F1 G. hirsutum hybrids in G. harknessii cytoplasm is enhanced by adding a genetic factor from the G. barbadense genome. Fertility in hybrid populations heterozygous for the restorer gene which possess the enhancer factor is comparable, if not superior, to that of the homozygous restorer lines which do not have the enhancer factor.Data strongly indicate that the enhancer factor derived from G. barbadense is controlled by a single gene expressing dominance. However, there is some indication that the enhancer may, in some instances at least, express incomplete dominance. The symbol E is proposed to denote the G. barbadense gene for fertility enhancement.
Variation Among Anther‐Derived Haploids from a Multiple Disease‐Resistant Tobacco Hybrid1
Authors: Burk L. G. , Chaplin J. F. 
Published: July 2010

Numerous chromosome‐doubled haploids (dihaploids) were obtained from cultured anthers of a tobacco (Nicotiana tabacum L.) hybrid with multiple disease resistance. Field plot tests of dihaploid progenies were made in 1977 (in the absence of diseases), and some of the highyielding entries observed in 1977 were included in a 1978 planting. The selections grown in 1977 consisted of four groups based on their resistance or susceptibility to Tobacco Mosaic Virus (TMV) and Potato Virus Y (PVY).Unlike dihaploids from inbreds, some of the dihaploids from the hybrid yielded significantly more than the midparent (MP). Four yielded more than the MP 1977, and six yielded more in 1978. Most of the entries that produced high yields in 1977 were also high‐yielding in 1978. Alkaloid values were extremely variable among dihaploid lines and highly uniform within them. Values for agronomic traits, averaged among entries in the group that was susceptible to TMV but resistant to PVY, indicated that the gene for PVY resistance was associated with increased yields and high grade indexes (values). Resistance to TMV or root knot (RK), caused by Meloidogyne incognita (Kofoid and White) Chitwood, was not particularly beneficial to the groups of entries that possessed those genes. However, individual entries with the same combinations of genes for resistance/susceptibility were found to be high‐yielding; some, contrary to expectation, also had high grade indexes. This finding suggests that large numbers of dihaploid lines should be evaluated to assure identification and selection of exceptional individuals for use as breeding stocks or as varietal candidates. The occurrence of exceptional in. dividuals from a hybrid anther source, coupled with the fact that a dihaploid is a true‐breeding, homozygous diploid, obtained in a single generation, offers encouragement for progress in breeding high‐yielding, disease: resistant tobacco.
Phenotypic Thermal Stability of Rhizobitoxine‐induced Chlorosis and the Nodulation Controlling Gene, rj11
Authors: Devine T. E. , Breithaupt B. H. 
Published: July 2010

The rj1 gene in soybeans (Glycine max L. Merrill), prevents nodulation with a broad range of strains of Rhizobium japonicum. Strains of R. japonicum that produce rhizobitoxine induced foliar chlorosis can nodulate rj1 plants in sand or vermiculite culture in the greenhouse. This study was undertaken to determine the effects of temperature on the expression of chlorotic symptoms and nodulation of rj1 plants, and to clarify the relationship between nodulation and chlorosis. Tests with plants cultured in Leonard jars in environmental control chambers maintained at 21, 27, and 32 C indicated that temperature modified the nodulation response of Clark rj1 soybeans with the chlorosis inducing strains 61 and 76. Chlorotic symptoms were beast evident at 21 C. Strain 61 produced good nodulation on rj1 plants at 21 C, but exhibited no induction of chlorosis at that temperature on the cultivar ‘Hawkeye.’ Strain 76 produced strong chlorotic symptoms on both the cultivars Hawkeye and ‘Peking’ at 32 C, but only a low level of nodulation with the rj1 plants. This differential effect of temperature on these two processes suggested that, while rhizobitoxine is correlated with both processes, separate control mechanisms with different temperature optima govern their expression.Increasing the temperature from 21 to 32 C mitigated the expression of the ineffective nodulation response of the Rj1 gene with strain 61 in the cultivar Peking. Despite the low level of nodulation (3.6 nodules per plant) of strain 61 with Peking at 32 C, chlorotic symptoms were clearly apparent.
Resistance to a Necrotic Strain of Soybean Mosaic Virus in Soybean1
Authors: Kwon Shin Han , Oh Jeung Haing 
Published: July 2010

Eighty‐nine entries from soybean [Glyclne max (L.) Merr.] germplasm collection and 47 cultivars were evaluated for resistance to necrotic infection by a strain of soybean mosaic virus (SMV‐N) in the field. Necrotic symptoms developed on 18 of the 136 entries with severity ranging from 4 to 86%. Many of the soybean cultivars evaluated were susceptible.Five resistant lines or cultivars previously identified as resistant to SMV‐N in field test, ‘KEX‐2,’ ‘Kumgangdaerip,’ ‘# 31926,’ ‘KAS 390‐10,’ and ‘KAS 150‐5,’ were crossed with either susceptible cultlvars ‘Kwangkyo’ or ‘Tachisuzunari’ to study the inheritance of resistance. All the F2 progenies of these crosses segregated in a 3:1 ratio of susceptible to resistant plants, indicating that resistance was conferred by a single recessive gene.
Responses of Early Corn Inbreds to Photoperiod1
Authors: Rood S. B. , Major D. J. 
Published: July 2010

Twelve early‐maturing inbred corn (Zea mats L.) lines were grown in controlled environments at photoperiods of 14, 16, 18, 19, 20, 21, 22, 23, or 24 hours. Days from emergence to anthesis increased as photoperiod increased for 10 of the 12 inbreds. The photoperiod response of the inbreds was adequately described by a three‐line model previously used for other plant species. Genotypic variability for the photoperiod response was identified.The basic vegetative phase, which is the time from emergence to anthesls in optimal photoperiod conditions, ranged from 37 to 57 days. The photoperlod sensitivity, expressed in days delay per hour increase of photoperiod, ranged from 0 to 2.5. The maximum optimal photoperiod, which is the longest photoperiod at which no photoperiod‐induced delay in anthesls is observed, ranged from 14 to 24 hours, and the critical photoperiod, above which no further delay in anthesis occurs, ranged from 21 to 24 hours. The photoperiod‐induced phase varied from 0 to greater than 17 days. A lack of correlation between components of the photoperiod response suggests independent regulation of these components.
Classification of Environments and Genotypes in Wheat1
Authors: Ghaderi A. , Everson E. H. , Cress C. E. 
Published: July 2010

Forty‐one genotypes (seven cultivars and 34 breeding lines) of winter wheat (Triticum aestivum L.) were planted in eight locations in each of 2 years. Test weight data were used to group locations according to their similarity of genotype ✕ location (G✕L) effects by cluster analysis. The results indicated that deletion of only one location from the variance analysis resulted in a group within which G ✕ L interaction was not significant. Such an analysis would be useful for the selection of testing sites for early generation testing and for development of genotypes with wide or narrow adaptability.The cultivars were also grouped into 10 clusters with respect to their test weight similarity across the 16 environments (2 years and eight locations). Further, stability parameters, i.e., mean, regression coefficient, and deviations from regression were calculated for each genotype. Cluster analysis effectively grouped genotypes according to their stability responses. Three broad categories of genotypes were identified with respect to their stability characteristics. Cluster analysis could be a useful supplementary tool for the analysis of adaptation reactions of wheat genotypes for test weight.
Comparisons Among Populations of Maize for Growth at 13°C
Authors: Hardacre A. K. , Eagles H. A. 
Published: July 2010

Six populations of maize (Zea mays L.), from high altitude sources in Mexico, Peru, and a high latitude source in Germany, and their crosses as males to two United States Corn Belt dent inbred lines (‘A619’ and ‘WI53R’) were compared for growth and survival at 13 C in a controlled environment with three U.S. Corn Belt dent hybrids (‘A632’ ✕ ‘A659,’ A619 ✕ A632, and WI53R ✕ A632).The objective of this study was to determine if any of these populations had the ability to grow autotrophically at 13 C, a temperature which was expected to be below the minimum for autotrophic growth of U.S. Corn Belt dent cultivars.At 13 C all plants grew heterotrophically utilizing seed reserves. However, major differences in the ability to grow autotrophicaly at 13 C existed among the genotypes studied. All genotypes containing germplasm from the high altitude Peruvian races ‘San Geronimo,’ ‘Huancavelicano,’ and ‘Confite Puneno’ were capable of autotrophic growth at l3 C as were genotypes from the CIMMYT (Centro Internacional de Mejoramiento de Maiz y Trigo) Pool 5. ‘Criollo die Toluca,’ predominantly of the high altitude Mexican race Conico, and ‘Bergenlaender,’ of the high latitude Norllhern Flint race, per se, were unable to grow at 13 C. However, their crosses with W153R and the cross A619 ✕ Criollo de Toluca were able to grow autotrophically at this temperature. Differences in growth rates existed between A619 and WI53R in crosses. Overall, crosses with W153R had the highest growth rates and crosses with A619 the lowest. The three U.S. Corn Belt dent hybrids did not grow autotrophically at 13 C.
Influence of Alfalfa Bud Mite on Growth of Alfalfa under Different Temperatures1
Authors: Ridland P. M. , Halloran G. M. 
Published: July 2010

The influence of four temperatures (15, 20, 25, and 29 C) on the growth of alfalfa (Medicago sativa L) seedlings, initially infested with 10 alfalfa bud mites (Eriophyes medicaginis Keifer) per seedling, was studied.Mite infestation caused significant reductions in dry weight of leaves and stems, petiole length, and leaf area of the seedlings at all temperatures. Dry weight reductions of infested seedlings were greatest at 25 and 29 C. The greatest reductions in stem and petiole length and leaf area occurred at 29 C. The reduction in total leaf area per plant due to mite infestation was similar at 15, 25 and 29 C but there was less reduction at 20 C.The influence of bud mite infestation on the growth of alfalfa seedlings appears to be expressed mainly as a reduction of extension growth. This results in reduced leaf expansion and reduced elongation of the stem and petiole.
Drought Response of Winter Wheat Cultivars Grown under Field Stress Conditions1
Authors: Keim D. L. , Kronstad W. E. 
Published: July 2010

Ten winter wheat cultivars (Triticum aestivum L.) were evaluated for grain yield and yield components under moisture stress conditions at three locations. Osmotic potential (Ψn.) was determined from leaf samples taken during the early part of grain filling. Consistent genetic differences were found for Ψn… Significant positive associations of Ψn with yield existed at two locations (r= 0.49 and 0.45). Path‐coefficient analysis indicated that Ψn. contributed positively to yield differences primarily by way of kernel weight at Pendleton, the least stressed site. Increased Ψn made contributions to high yield via spikelets/spike, kernels/spikelet, and kernel weight at Pilot Rock, a severely stressed site. High spike numbers had a tendency to be associated with low plant water status (low Ψn). At Heppner, the large direct effect on yield by spikes/m2 negated the small positive indirect effects of Ψn via the later‐developed yield components. In a growth analysis study at Pilot Rock, five cultivars were sampled over four time intervals from spike initiation to ripe stage. The mean Ψn decreased over time (‐ 17.1 to ‐ 31.8 bars). Cultivar Ψn values ranked consistently and differences became larger after the onset of high soil moisture stress (< ‐ 15 bars).The drought‐resistant cultivar ‘Yamhill’ avoided drought stress by maintaining a high plant water status during reproductive development. The high growth rates during heading and anthesis and a high kernel weight indicated that this cultivar was less affected by high external water stress. The drought‐resistant cultivar ‘Wanser’ tolerated a high internal stress by maintaining a large number of tillers through development to harvest. Characterization of other cultivars also indicated that both avoidance and tolerance traits contributed to grain yield under drought stress.
Comparison of Narrow and Broad Leaflet Isolines of Soybean1
Authors: Mandl F. A. , Buss G. R. 
Published: July 2010

We evaluated the effect of leaflet shape on the agronomic performance of soybeans, Glycine max (L) Merr., by using pairs of narrow and broad leaflet isolines with varied genetic backgrounds.Results obtained from 1976 through 1978 indicated that the narrow leaflet isolines, on the average, were similar in seed yield to those with broad leaflets. Analyses over years showed the narrow leaflet isolines were significantly shorter and had smaller seeds. They were significantly earlier in 2 of the 3 years. Lodging scores were similar for both leaflet types. All differences were small and of little practical significance. We concluded that the narrow leaflet trait offers neither a yield advantage nor disadvantage compared with the broad leaflet trait.
Changes in Physiological Traits Associated With Grain Yield Improvement in Three Maize Breeding Programs1
Authors: Crosbie T. M. , Mock J. J. 
Published: July 2010

Plant breeders and plant physiologists would like to know which plant traits have changed to permit new varieties to produce higher yields than older varieties. We studied crosses of improved and unimproved cycles from three recurrent selection programs conducted to increase grain yield in maize (Zea mays L.). Our research was conducted to study changes in several physiological traits that could be important to increased grain production.Results suggested that an extended grain filling period and later plant senescence rather than an increased rate of grain filling was associated with grain yield increases in BS10(FR) x BS11(FR). Testcrosses of the improved Lancaster population produced more dry matter and translocated dry matter to developing kernels at a faster rate and for a longer period of time than did testcrosses of the unimproved population. Crosses of improved cycles of BSSS(R) and BSCBl(R) generally displayed more rapid filling periods and later plant senescence than did crosses of their unimproved cycles. Crosses of improved cycles generally produced more dry matter and translocated a larger percentage of dry matter to the grain.
The Seed Coat as a Control of Imbibitional Chilling Injury
Authors: Tully Raymond E. , Musgrave Mary E. , Leopold A. Carl 
Published: July 2010

The imbibition of pea (Pisum sativum L.) seeds proceeds slowly in cold water, with little effect on subsequent vigor; soybean [Glycine max (L.) Merr.] seeds imbibe cold water rapidly, and suffer significant vigor loss. When the imbibitional rate of peas was increased by nicking the seed coats, the peas became susceptible to chilling injury. Conversely, when the rate of soybean imbibitionwas slowed with a solution of polyethylene glycol (PEG 6000), their susceptibility to imbibitional chilling was considerably lessened. Sensitivity to imbibitional chilling is thus a consequence of the rate of cold water uptake.Cellular damage to cold‐imbibed peas and soybeans was assessed as inability to reduce triphenyl tetrazolium chloride (TTC). Peas showed only a low level of damage when imbibed with intact seed coats at 2 C, but increased damage when imbibed with nicked seed coats. Soybeans, however, showed considerable cellular damage when imbibed intact, and no further damage when imbibed with nicked seed coats. Pea seed coats thus offer considerable protection against rapid imbibition and chilling damage, whereas the soybean seed coat offers little.Soybeans with black‐pigmented seed coats imbibed water more slowly than nonpigmented soybeans. Blackpigmented soybeans also showed less vigor loss following imbibition at 0 C, and exhibited no cellular damage as determined with TTC stain. Vigor of blackpigmented seeds after 23 C imbibition was less than that of nonpigmented, however, due to a slower rate of radicle penetration of the tougher black seed coats.
Drought Resistance of Cowpea Improved by Selecting for Early Appearance of Mature Pods1
Authors: Hall A. E. , Grantz D. A. 
Published: July 2010

We hypothesized that earlier partitioning of carbohydrate to reproductive parts by cowpeas [Vigna unguiculata L. (Walp.)] would result in improved drought resistance. We selected individual plants from adequately‐irrigated fields of the cultivar, California Blackeye No. 5 (CB5), and a land race of California Blackeyes, in southern California. The selection criterion was early appearance of mature pods.Seeds of the selections and populations were bulked in a greenhouse. Phenology, growth, partitioning, and yield were examined at Riverside, Calif. over three summer growing seasons with both optimal irrigation and a treatment which received no irrigation or rainfall after seedling emergence. No differences were observed among the selections and populations in ability to extract water from the soil.The selection from CB5 flowered earlier, and had substantially more dry matter in peduncles and pods during early stages of pod development, than CB5, in both irrigated and non‐irrigated conditions. At maturity, this selection had a higher harvest index and yielded 53% more seed than CB5, under non‐irrigated conditions, and a similar harvest index and seed yield as CB5 under irrigation.In non‐irrigated conditions, the selection from the land race had more dry matter in peduncles and pods during early stages of pod development, a higher harvest index at maturity, and yielded 19% more dry seed than the land race. No significant differences were observed in earliness, partitioning, harvest index, or seed yield between this selection and the land race under irrigation. All strains had similar biomass production and seed yield under irrigation.
Sampling Stomatal Density in Alfalfa1
Authors: Carlson J. R. , Ditterline R. L. , Martin J. M. , Lund R. E. 
Published: July 2010

Sample size requirements for stomatal density studies in alfalfa (Medicago sativa L.) are not documented. This study was conducted to refine sampling techniques and to determine whether the sampling required to estimate stomatal density is too extensive to use this trait as a possible rapid screening criterion for drought resistance in alfalfa.Stomatal and epidermal cell counts were made on abaxial and adaxial leaflet surfaces sampled at three nodes from 10 stems of five alfalfa plants. These plants differed significantly in stomatal densities on abaxial and adaxial leaflet surfaces. Leaflets from the uppermost node sampled had higher stomatal densities than those from lower nodes.Variability from counts on leaflets from stem to stem rather than variability in counts from microscopic field to microscopic field within a leaflet contributed most to overall imprecision in estimation of mean counts per plant. To increase precision and efficiency, efforts should thus be directed toward sampling leaflets on more stems and not toward more fields on a leaflet. Number of stem samples required to detect given differences between plants at specified probability levels have been tabulated.Due to the large level of within‐plant variability for stomatal density in alfalfa, we decided that the sampling required was too extensive to pursue this trait in a breeding program for drought resistance.
Resistance of Sweet Potato Cultivars to African Sweet Potato Weevil1
Authors: Hahn S. K. , Leuschner K. 
Published: July 2010

Twenty sweet potato (Ipomoea batatas L.) cultivars, including two orange‐fleshed and 18 white‐fleshed types, were evaluated in the field for resistance to African sweet potato weevil (Cylas puncticollis Boh.). The cultivars showed significant differences in weevil resistance in separate evaluation of roots and shoots. Cultivars with the most resistant roots were ‘TIS 3053’ and ‘TIS 3030.’ Cultivars with the most resistant shoots were ‘TIS 2532,’ ‘TIS 3017,’ and TIS 3030. A highly significant correlation (r = 0.74) was noted between weevil damage ratings of roots and damage ratings of shoots.A highly significant negative correlation between weevil root damage scores and root dry matter percentage was obtained (r = −0.56), but fresh root yield or average weight were not correlated with weevil damage.
Stormproof Boll in Upland Cotton III. Genotype‐Environment Interaction and Genetic Analysis1
Authors: Quisenberry J. E. , Dilbeck R. E. 
Published: July 2010

Stormproofness (lock tenacity) of cotton (Gossypium hirsutum L.) was defined as the amount of force required to extract a locule of seedcotton from the bur of a mature boll. Six entries representing the range of variability in stormproofness of Upland cotton were grown in seven environments to study the relationship of the character to temperature and precipitation. In a separate experiment, a complete diallel set of crosses among the six entries was grown for 2 years to estimate general (GCA) and specific combining ability (SCA) associated with the inheritance of the stormproof trait.In general, stormproofness increased as temperature during the boll maturation period decreased or seasonal precipitation increased. Temperature appeared to influence stormproofness more than precipitation, although responses among the entries varied. ‘Acala 1517 BR‐2,’ TM‐1, Contextum, and ‘Macha’ were more responsive to temperature than to precipitation. Unique Stormproof was about equally influenced by both variables, and ‘Lankart Sel. 57’ was most responsive to precipitation. Results from the genetic study revealed that significant GCA and SCA effects were associated with the expression of stormproofness, but that the SCA effects were small and hybrids tended to be intermediate between their respective parents. The GCA effects interacted with years primarily as a result of relative changes in lock tenacity between the stormproof and nonstormproof cultivars. A relationship between lock tenacity and the percentage of storm loss (seedcotton that fell on the ground) showed that hybrids between non stormproof cultivars may suffer relatively high storm losses.