Download or read book Genotype environment Interaction and Phenotypic Stability of Selected Winter Wheats Triticum Aestivium L Em Thell written by Mark J. Larson and published by . This book was released on 1997 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive research has been devoted to evaluating potential genotype-environment interactions. However, plant breeders are still in need of a simple way to describe how genotypes respond to different locations and years. In an environmentally diverse state like Oregon, significant genotype-environment interactions do occur The resulting lack of association between actual and genotypic potential yield performance makes it difficult to select genotypically superior lines. This study was prompted to evaluate the extent of such an interaction and compare various yield stability models. A significant genotype-environment interaction encompassing lines, environments, and years was discovered for each individual year analyzed and for the combined analysis of 1992, 1994 and 1995, and 1989 through 1994. Most lines evaluated during 1992, 1994 and 1995 were adapted to low yielding environments. However, two genotypes (OR880172 and OR880525) exhibited broad adaptation. Stephens and Mac Vicar were less adapted to the relatively high yielding Chambers site than the other genotypes tested during 1992, 1994 and 1995 due to Septoria tritici infections. The most stable genotypes during the combined 1992, 1994 and 1995 and 1989-1994 seasons were OR870831, Madsen and OR8500933H. Gene was the most desirable genotype based on stability and yield for both the combined 1992, 1994 and 1995 and 1989-1994 seasons. Due to an inability to adapt to higher yielding environments, the cultivar Rohde was the least stable genotype during the same combined periods. High and low temperatures and precipitation had minor yet significant effects on yield responses at all three sites during various periods identified. Advanced winter wheat selections and cultivars were grown in three diverse environments and compared over different time periods. Due to trial design and the objective of identifying superior genotypes from a set tested in target environments a combination of two methods, stability variance and a selection index, emerged as the most appropriate techniques. These approaches are considered the most appropriate because they use the mean of the trial as a gauge for measuring stability.
Download or read book Nature of Inheritance Genotype environment Interaction and Association of Selected Agronomic Characters in Crosses of Winter X Spring Wheats Triticum Aestivum L Em Thell written by P. Brajcich and published by . This book was released on 1980 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: This investigation was motivated by the apparent increase in genetic variability resulting from the systematic combining of gene pools represented by winter and spring types of wheats. It was the objective of this study to provide information regarding the nature of this genetic variability for nine agronomic characters in populations resulting from winter x spring crosses. Evaluations were made for: 1) the amount of total genetic variability; 2) the nature of the gene action making up this genetic variability using parent-progeny regression and combining ability analysis and 3) possible direct and indirect associations for traits which influence grain yield. Experimental populations which involved parents, Fl, F2 and backcross generations were grown at two locations where a spring and a winter environment could be utilized. At the winter site, the research was evaluated over a two year period. When the two experimental sites were compared, greater genetic diversity was observed at the spring site for maturity date, plant height, tillers per plant, kernel weight and grain yield. At the winter site, heading date, grain filling period, harvest index and kernels per spike were found to have more total genetic variation. From the expected mean square values, it would appear that the winter parents contributed more to the total genetic variation for most traits measured at both locations. A large genotype-location interaction was also noted suggesting that estimates of gene action and selection for adapted plant types can be done only at the specific winter or spring site. A large portion of the total genetic variation controlling the traits measured was due to additive gene action. However, at the winter site there was also a large influence of non-additive gene action associated with heading date, plant height, harvest index, tillers per plant, kernel weight, kernels per spike and grain yield. Of special interest was that at the winter site the most promising parental combinations could be predicted based on the general combining ability effects of the individual cultivars for each trait studied. Such data were not available for the spring site. Consistent and high correlations were observed between tillers per plant, kernels per spike and, to a lesser extent, kernel weight and grain yield at the winter location. Some negative associations were observed at the spring location between these traits and grain yield suggesting that yield component compensations were involved in the final expression of grain yield. The other characters measured did not reflect significant correlations with yield. When the correlation values were considered in terms of direct and indirect effects for specific traits, a large direct effect was noted for the three components and grain yield. The other traits exhibited small or no direct effects on grain yield but did have a slight influence on grain yield through tillers per plant, kernels per spike or kernel weight.
Download or read book Inheritance and Genotype environmental Studies of Test Weight and Related Kernel Characteristics in Soft Winter Wheat Triticum Aestivun L written by Ardeshir Ghaderi and published by . This book was released on 1969 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parametric Analysis to Describe Genotype X Environment Interaction and Yield Stability in Winter Wheat written by John Luscombe Purchase and published by . This book was released on 1997 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Winter Wheat Cultivar Performance in an International Array of Environments written by James Edward Stroike and published by . This book was released on 1972 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Bulletin written by and published by . This book was released on 1972 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Residential Environment Studies Relevant for Research Programs written by C. R. Fenster and published by . This book was released on 1971 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genotype by Environment Interaction written by Manjit S. Kang and published by CRC-Press. This book was released on 1996-02-06 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genotype-by-Environment Interaction (GEI) is a prevalent issue among crop farmers, plant breeders, geneticists, and production agronomists. This book brings together contributions from expert plant breeders and quantitative geneticists to better understand the relationship between crop performance and environment. This information can reduce the cost of extensive genotype evaluation by eliminating unnecessary testing sites and by fine-tuning breeding programs. Molecular aspects of GEI are discussed for the first time and key bibliographical references on GEI are included in an appendix.
Download or read book Agronomy Abstracts written by and published by . This book was released on 1984 with total page 292 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 Plant Breeding Abstracts written by and published by . This book was released on 1995 with total page 1238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plant Breeding Perspectives written by J. Sneep and published by Bernan Press(PA). This book was released on 1979 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bread Wheat written by Food and Agriculture Organization of the United Nations and published by Food & Agriculture Organization of the UN (FAO). This book was released on 2002 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wheat is the most widely grown cereal crop in the world, with an ever increasing demand. It plays a fundamental role in food security, and a major challenge is to meet the additional requirements with new cultivars and improved cropping technologies. This book covers information from a number of international experts on the current status of research on wheat improvement and production (wheat breeding programs and genetics), as well as on other aspects (including wheat diseases), from its evolutionary origins to seed production technologies. [from the FAO website]
Download or read book Agrindex written by and published by . This book was released on 1994 with total page 1014 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 1984 with total page 1086 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1973- include the following subject areas: Biological sciences, Agriculture, Chemistry, Environmental sciences, Health sciences, Engineering, Mathematics and statistics, Earth sciences, Physics, Education, Psychology, Sociology, Anthropology, History, Law & political science, Business & economics, Geography & regional planning, Language & literature, Fine arts, Library & information science, Mass communications, Music, Philosophy and Religion.
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 Genotype X Environment Interactions written by Paolo Annicchiarico and published by Food & Agriculture Org.. This book was released on 2002 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: The projected increase in world population levels and the subsequent rise in food demand represents a huge challenge for agricultural production systems worldwide. This publication examines the opportunities and challenges raised by the use of plant genetic resources and highlights the contribution that data from multi-environment yield trials can provide for the definition of adaptation strategies and yield stability targets in plant breeding programmes. It contains a case study about a durum wheat crop programme in Algeria, and also includes a CD-ROM with data from IRRISTAT, a programme developed by the International Rice Research Institute (IRRI).
