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Book Specific Combining Ability Estimates in Winter Wheat Crosses

Download or read book Specific Combining Ability Estimates in Winter Wheat Crosses written by Surendra Prasad Sinha and published by . This book was released on 1962 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Heterosis Combining Ability and Variance covariance Relationships in a Diallel Cross Among Six Common Wheat Varieties of Diverse Origin

Download or read book Heterosis Combining Ability and Variance covariance Relationships in a Diallel Cross Among Six Common Wheat Varieties of Diverse Origin written by William Oliver McIlrath and published by . This book was released on 1967 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Agronomy Abstracts

Download or read book Agronomy Abstracts written by and published by . This book was released on 1986 with total page 308 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).

Book Heterosis and Combining Ability Estimates Derived from a Diallel Set of Crosses Among Maryland and Pennsylvania Tobaccos

Download or read book Heterosis and Combining Ability Estimates Derived from a Diallel Set of Crosses Among Maryland and Pennsylvania Tobaccos written by Janet R. Broome and published by . This book was released on 1978 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Estimates of Heterosis for Five Agronomic Traits in Selected Winter X Spring and Winter X Winter Wheat Crosses Triticum Aestivum L Em Thell

Download or read book Estimates of Heterosis for Five Agronomic Traits in Selected Winter X Spring and Winter X Winter Wheat Crosses Triticum Aestivum L Em Thell written by P. Brajcich and published by . This book was released on 1980 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concern regarding the lack of genetic variability and the apparent yield plateau reached in wheat breeding have prompted this investigation. The systematic crossing of spring and winter wheat types which have evolved to form somewhat different gene pools, may provide a source of additional usable genetic variability for future yield increases. Five winter and five spring wheat cultivars with different degrees of genetic similarities in their pedigrees were crossed to obtain F1's and F2's. The parents plus winter x spring F1's were planted in two growing seasons at Hyslop Agronomy Farm near Corvallis, Oregon. During the second season the winter x spring F2 and winter x winter F1 crosses were also included. Agronomic traits were measured on an individual plant basis. These traits were plant height, number of tillers per plant, 100 kernel weight, number of kernels per spike and grain yield. Analyses of variance were conducted for each trait. Estimates of the amount of usable genetic variation were determined by heterosis values, inbreeding depression and parent-progeny standard regressions. Possible interactions between years and the above five characters were determined for the winter x spring F1's. Evidence of non-additive gene action was found in the expression of heterosis and subsequent inbreeding depression which depended on the specific trait measured and the parents involved in the cross. The greatest heterosis values were noted for grain yield per plant. Crosses with the winter parent, Weique Red Mace, resulted in the highest estimates for grain yield. This was due to the late maturity of these hybrids and to the diverse genetic background of this winter parent compared to the five spring parents. Parent-progeny regressions indicated that a large amount of additive genetic variance was present for plant height, 100 kernel weight and grain yield an intermediate amount for kernels per spike and tillers per plant. Winter x spring F1 crosses resulted in higher heterosis estimates and a wider range of values between crosses than winter x winter F1 crosses. Parent-progeny regression estimates were similar in value for the two types of F1 populations. Thus, these results indicate that the systematic crossing between winter and spring wheats will produce greater total genetic variability for further wheat improvement. This is true for the development of hybrid wheat (non-additive) and may also be promising for conventional breeding programs when only the additive portion of the total genetic variance can be used. The data support the general conclusion that the amount of heterosis is a function of genetic diversity between the two parents. Those breeders working on hybrid wheat may wish to look at winter x spring crosses as a means of maximizing heterosis. However, since a significant interaction between years x F1's was noted for the traits measured, more than one year of evaluation will be necessary if winter x spring crosses are employed.

Book Journal of Agricultural Research

Download or read book Journal of Agricultural Research written by and published by . This book was released on 1994 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Combining Ability and Gene Action Estimates and the Association of the Components of Yield in Winter Wheat Crosses

Download or read book Combining Ability and Gene Action Estimates and the Association of the Components of Yield in Winter Wheat Crosses written by Warren Ervind Kronstad and published by . This book was released on 1963 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: A diallel cross consisting of ten parents was grown on the Hyslop Agronomy Farm near Corvallis, Oregon, in order to obtain estimates of the gene action contributing to yield and its components in wheat. Gene action estimates were obtained by two methods of diallel analysis and from narrow sense heritability values calculated by parent-progeny regressions involving both parental and F[subscript 1] data. In addition, path-coefficient analysis was utilized to investigate the direct and indirect associations of five variables on yield. The morphological characters measured were: (1) total yield per plant, (2) weight per kernel, (3) number of kernels per spikelet, (4) number of spikelets per spike, (5) number of spikes per plant and, (6) plant height. A large portion of the total genetic variation associated with the yield components, weight per kernel, kernels per spikelet, spikelets per spike and spikes per plant was the result of additive gene action. When the five variables were considered in terms of their associations with yield it was observed that weight per kernel, number of kernels per spikelet and the number of spikelets per spike mainly exerted direct effects on yield. The number of spikes per plant had no direct effect, but an indirect effect on yield through the other variables. A similar indirect association was noted for plant height. The data obtained from the path-coefficient analysis indicated further that the number of kernels per spikelet had the greatest direct effect on yield. Results obtained with correlation coefficients suggested that a negative association exists between weight per kernel and kernels per spikelet. Also such a negative association was found between the number of spikes per plant with weight per kernel and kernels per spikelet. These results would suggest the possible existence of a biological limitation between several of the components of yield. The diallel cross analysis for general and specific combining ability gave similar estimates of gene action when they were compared to narrow sense heritability values. However, when the Jinks-Hayman method was compared with the other two methods of estimating gene action, several discrepancies were observed. This lack of agreement was possibly due to the inability of this experimental material to meet one or all of the genetic assumptions required by the Jinks-Hayman method. The results of this study indicate that a breeding program with emphasis on increases in yield which considers each of the components separately, or in combination of two or more would offer the most promise. By this procedure the breeder could take advantage of the large amount of additive genetic variance associated with each of the components and at the same time, take into consideration any biological limitations which may exist. In utilizing the information obtained in this study in such a breeding procedure the plant breeder would be able to better evaluate the methods for selecting the best parents to be hybridized and in selecting the best lines from hybrid progeny.

Book Agricultural Research Review

Download or read book Agricultural Research Review written by and published by . This book was released on 1977 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Journal of Cytology and Genetics

Download or read book The Journal of Cytology and Genetics written by and published by . This book was released on 1978 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Pakistan Journal of Agricultural Research

Download or read book Pakistan Journal of Agricultural Research written by and published by . This book was released on 2000 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Principles and Methods of Plant Breeding

Download or read book Principles and Methods of Plant Breeding written by Slavko Borojević and published by Walter de Gruyter GmbH & Co KG. This book was released on 1990-12-31 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: No detailed description available for "Principles and Methods of Plant Breeding".