Download or read book Response of Grain Yield Plant Height and Kernel Weight in Three Winter Wheat Crosses Triticum Aestivum L Em Thell to Different Methods of Selection written by Jose Juan Salmeron-Zamora and published by . This book was released on 1985 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was undertaken to see if a method of handling segregating populations could be employed which combined the positive attributes of the traditional pedigree and-bulk methods. Derived F5 lines from the pedigree, bulk, and what is identified as a modified bulk method, were obtained from three winter wheat crosses. The effectiveness of the methods, representing different cycles of phenotypic selection, were evaluated in terms of plant height, plant ideotype and indirectly kernel weight and grain yield. To assess differences in levels of heterogeneity in relation to possible line x environment interactions, the material was grown at three diverse experimental sites. The modified bulk method was as effective as the pedigree method in establishing the desired semi-dwarf height level. Due to the competitive advantage of taller plants, dwarf and semi-dwarf height levels were eliminated in the unselected populations resulting from the bulk method. Although differences were observed for kernel weight between methods, no consistent trends for this trait were established when crosses and locations were considered. Based on the combined mean values of the F5 lines for each method across and within locations, the modified bulk method was superior for grain yield in only one cross. However, when individual F5 lines were compared, a higher percentage of lines obtained from the modified bulk method were superior across and within locations in two of the crosses. Data from this study suggests that to reduce the variety x environment interaction it is important to maintain a level of genetic heterogeneity within varieties. The modified bulk method does appear to be an efficient compromise in handling segregating populations when compared to the traditional pedigree and bulk methods. It is also more efficient in terms of maximizing limited resources which can be important in developing countries where funds and trained scientist are limited.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1991 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plant Breeding Abstracts written by and published by . This book was released on 1999 with total page 1664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agronomy Abstracts written by and published by . This book was released on 1989 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes abstracts of the annual meetings of the American Society of Agronomy; Soil Science Society of America; Crop Science Society of America ( - of its Agronomic Education Division).
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1984 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genetics Abstracts written by and published by . This book was released on 1991 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Duration and Rate of the Grain Filling Period and Subsequent Grain Yield in Crosses Between Facultative and Winter Wheat Cultivars Triticum Aestivum L Em Thell written by Beiquan Mou and published by . This book was released on 1985 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concerns about the genetic control and environmental influence of various stages of development including the grain filling period, and the relationship between early maturity and grain yield prompted this study. The experimental material consisted of two facultative and two winter wheat cultivars. A dial!el cross, excluding reciprocals, was also developed to provide an Fl generation. Information was collected for 14 traits and subjected to statistical analyses. Genetic differences among varieties were found for time of heading, flowering and physiological maturity, duration and rate of the grain filling period, grain yield and yield components. The facultative types, AI Feng 2 and Selection CB 83-52, showed earlier heading, flowering and physiological maturity, longer lag period (period between heading and flowering), and longer duration and lower rate of grain filling, resulting in lower grain yield. The winter cultivars, Stephens and Yamhill Dwarf, in contrast had later heading, flowering and maturity, shorter lag period, and shorter duration and higher rate of grain filling, giving higher grain yield. For the developmental stages after heading, larger differences were observed in the lag period while differences in duration of grain filling period were relatively small among the cultivars. Depending on the specific Fl population, there was a tendency toward dominance for early heading, a range from no to complete dominance for early flowering and no dominance for physiological maturity. Long duration and fast rate of grain filling were generally dominant. Grain yield was positively associated with the number of days to heading, flowering and physiological maturity. Also positive associations of grain yield were obtained with tiller number, kernel weight, grain weight per spike, biological yield and rate of grain filling. Negative associations of grain yield were noted with lag period and duration of grain filling period. No clear associations between physiological maturity and the yield components were found. Grain filling duration showed no association with yield components while grain filling rate exhibited positive association with tiller number and kernel weight. There was negative association between duration and rate of grain filling period. According to heading responses from different planting dates, Stephens and Yamhill Dwarf had high sensitivity while Selection CB 83- 52 and AI Feng 2 showed low sensitivity to vernalization. Genotype X environment interaction was observed with each cultivar responding differently for several traits depending on the planting dates.
Download or read book Biotechnology Research Abstracts written by and published by . This book was released on 1987 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monthly. Classified listing of references to worldwide articles dealing with all aspects of biotechnology. Also includes books and conferences. Each entry gives bibliographic information, institutional address of author(s), and abstract. Author and subject index.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1976 with total page 1732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture with Subject Index written by and published by . This book was released on 1979 with total page 1426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1990-07 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Meetings Abstracts written by American Society of Agronomy and published by . This book was released on 2000 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Cultivars Hybrids and Composites of Winter Wheat Triticum Aestivum L Em Thell Grown at Three Locations written by Ruben P. Verges and published by . This book was released on 1987 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to compare three genetically different groups of winter wheat for their grain yield. Experimental material consisted of parental lines grown in pure stands, hybrids, and 1:1 mixtures of the parental combinations. Three sites were employed to evaluate possible interactions between the different groups across locations. Phenotypic correlations among selected agronomic traits and grain yield within each group along with the expression of heterosis and heterobeltiosis in the hybrids were studied. Results of this investigation support the general conclusion reached by other investigators that hybrids and composites are not consistently superior to the best conventional cultivars of wheat for grain yield. However, at the Moro site, with the greater environmental stresses, some hybrids and composites appeared to yield more than the parental lines grown in pure stands. At Pendleton, the best environment for yield expression, the hybrids and conventional cultivars did not differ for grain yield. At this location, the best hybrids and one composite did significantly outyield the commercial cultivars Stephens, Malcolm and Hill, but not four advanced parental selections when grown in pure stands. Low to moderate values of heterosis and heterobeltiosis for grain yield were found. The degree of expression being affected by the specific growing site. Plant height and the number of kernels per spike showed relatively higher values for heterosis and heterobeltiosis over locations when compared to the other traits. Phenotypic correlations suggested that a breeding program to develop hybrid wheat should combine high number of kernels per spike with high kernel weight. The positive correlation between grain yield and plant height indicated that increases in grain yield could be obtained by increasing plant height if lodging did not present a problem.
Download or read book Agronomy News written by and published by . This book was released on 1982 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sept.-Oct. issue includes list of theses and dissertations for U.S. and Canadian graduate degrees granted in crop science, soil science, and agronomic science during the previous academic year.
Download or read book Agriculture Agronomy written by University Microfilms International and published by . This book was released on 1977 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
