Download or read book Effect of Selection for Certain Grain Characters on Yield in Bread Wheat Triticum Aestivum L Em Thell written by Behari Lal and published by . This book was released on 1976 with total page 113 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 1998 with total page 1212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Association of Selected Traits with Visual Selection for Yield in Wheat Triticum Aestivum L Em Thell written by Michael E. Marciniak and published by . This book was released on 1983 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visual selection for grain yield may be a limiting factor in identifying superior yielding genotypes in a breeding program. This investigation was conducted (1) to compare the effectiveness of visual selection for grain yield by three selector groups representing different levels of plant breeding experience, and (2) to examine the association of selected traits with the process of evaluating plots visually for grain yield. The germplasm evaluated consisted of fifty non-segregating, diverse genotypes selected to include a wide range of expression for phenotypic characters. They were grown in solid-seeded, two-row plots with three replications in a randomized block design during 1981-1982. Data were collected on a plot basis for grain yield and twenty-two agronomic traits. Eighteen selectors were placed in three groups comprised of two plant breeders, eight graduate students, and eight summer student workers, respectively, from the Oregon State University cereal breeding program. Evaluations were made on two separate days by scoring each of the 150 plots on a scale of 1 to 5 for grain yield. The plant breeder selectors were the most successful of the three groups in discriminating both high and low yielding plots. The two best graduate student selectors were similar in ability to the plant breeders in scoring plots for high yield, although not in scoring for low yield. The remaining graduate student and summer worker selectors were generally not able to score more low and high yielding plots "correctly" than would be expected if selection were done at random. Considered individually, the most effective selectors failed to select several high yielding plots. However, when selections of the four most effective selectors were combined, only one of the twenty highest yielding plots was omitted. Results comparing trait association with actual plot grain yield and with selector scoring for plot grain yield suggested "biases" for or against certain traits. Biases for later heading and maturing plant types with wide flag leaves were common to all selector groups when visually selecting for high yield, as were earlier heading and maturing entries with narrower flag leaves when selecting for low yield. The plant breeder selectors were notable for lack of trait biases relative to other selector groups. In contrast, the summer worker selectors tended to overemphasize several spike characteristics whether selecting for high or low yield. Results suggested several other trait biases of individual selectors and selector groups.

Download or read book Genetic Analysis of Grain Yield and Related Characters in Bread Wheat T Aestivum L em Thell Under Normal and Stress Environments written by Vijaipal Singh and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Increasing Yield Potential in Wheat written by M. P. Reynolds and published by CIMMYT. This book was released on 1996 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Indian Journal of Agricultural Sciences written by and published by . This book was released on 2014 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stability Analysis of Yield and Yield Attributing Characters of Promising Bread Wheat Triticum Aestivum L Em thell Genotypes With CD Copy written by Vijeta Gupta and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Indian Journal of Genetics Plant Breeding written by and published by . This book was released on 2006 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Inheritance of Important Traits in Bread Wheat Using Diallel Analysis written by Inam Ullah and published by LAP Lambert Academic Publishing. This book was released on 2011-01 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bread wheat (Triticum aestivum L. em. Thell) is one of the most important cereal grain crop of the world and is cultivated over a wide range of climatic conditions. For a successful breeding program the inheritance of yield related traits is a pre- requisite. This monograph communicates the inheritance pattern of yield and related traits in bread wheat (Triticum aestivum L.) using 8x8 diallel analyses. Graphical analysis revealed additive gene action for days to heading, days to maturity, plant height, grains per spike, 1000 grains weight and harvest index. While over dominance gene action for flag leaf area, tillers per plant, Spike length and yield per plant. The GCA mean squares were significant for all traits except tiller per plant and yield per plant and were greater than SCA mean squares indicating the preponderance of additive genetic effects. The parents Tkb, Tat, Sarc-3 and SQ- 92 were good general combiners. The parents Tkb , Tat , Sarc-3 and SQ-92 and the specific crosses that showed high mid parent and better parent heterosis are recommended for further use in wheat breeding programmes.

Download or read book Combining Ability and Associations of Agronomic Traits Involving Three Sources of Dwarfism in Wheat Triticum Aestivum L Em Thell written by Jose Luis Maya de Leon and published by . This book was released on 1974 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three genetically different dwarf cultivars of spring wheat were evaluated as potential sources of short stature to use in a wheat improvement program. The study involved a five parent diallel cross which included a semidwarf, a standard height and three dwarf cultivars. The genetic sources of dwarfism included a Norma 10 derivative named Vicam 71, a derived line from Tom Thumb called Tordo, and Olesen dwarf. Experimental material consisted of parental lines, F1, F2, and both backcrosses to the parents space planted in a randomized block design. The agronomic characters measured on an individual plant basis were: (1) plant height, (2) days to heading, (3) number of tillers, (4) number of spikelets per spike, (5) head length, (6) days to maturity, (7) grain yield, (8) harvest index, (9) kernel weight, (10) number of kernels per spikelet, (11) rachis internode length, (12) grain filling period and, (13) head grain weight. Estimates of gene action were determined by heterosis, heterobeltiosis, broad and narrow sense heritabilities and combining ability analyses. Associations among traits were estimated by phenotypic, environmental, and genotypic correlations as well as path-coefficient analysis for grain yield and eight of the variables. There were significant differences among the parental lines, their crosses, and generations for all traits measured. Either partial dominance for tallness or no dominance was manifested for those crosses involving the dwarf cultivars Vicam 71 and Olesen. Tordo, when crossed to taller wheats showed dominance for short stature. All three genetic sources of dwarfism and their resulting progenies manifested desirable agronomic characteristics. Vicam 71 was a good parent in terms of grain yield and number of tillers per plant. Tordo was the best source for increasing the number of spikelets per spike, kernel weight and head grain weight. Olesen was a good progenitor for increasing number of kernels per spikelet. All three dwarf cultivars displayed some advantage(s) over the other two and all could be used to breed short statured wheats with a possibility of success. Plant height did not appear to have a direct effect on plant grain yield in any of the 10 crosses. With the exception of number of tillers per plant and grain yield, a major proportion of the phenotypic variability observed for all characters studied was due to genetic factors. A large portion of the total genetic variability associated with days to heading, maturity, height, rachis internode, spikelet number, kernels per spikelet, kernel weight, and harvest index was mainly a result of additive gene action. Both additive and non-additive genetic effects were involved in the expression of grain filling period and head weight. The nonadditive portion of the genetic variance associated with tiller number and grain yield per plant was relatively large when compared with the additive portion. Therefore, selection for increased expression of tillers and yield should be delayed until the F4 or later generations where a large degree of homozygosity has been obtained. The genetic correlations for individual crosses indicated that only a few of the traits studied were associated in the same manner in most or all the 10 hybridizations. High positive genetic correlations were found between plant grain yield vs tiller number and kernels per spikelet, tiller number vs days to maturity, kernels per spikelet vs head grain weight, plant height vs head weight, and head length vs rachis internode length. High negative genetic correlations were found between kernel weight vs days to maturity, plant height vs harvest index, and days to heading vs grain filling period. Most correlations among agronomic traits were different in value and/or sign from one cross to another suggesting different gene associations in the parental cultivars. Genetic correlations between components of yield showed this type of inconsistency. Therefore, grain yield could be increased by a combined increase of more than one component of yield without compensatory oscillation among them because tiller number, spikelet number, kernels per spikelet and kernel weight were often not correlated between one another and sometimes were positively correlated. Path-coefficients analysis indicated that number of tiller per plant had a high direct effect on grain yield in all crosses. With the exception of two crosses, indirect effects of this trait were negligible. In the latter two crosses tiller number had a high negative indirect effect on plant grain yield via head grain weight. Kernels per spikelet and kernel weight had no direct effects on grain yield but their indirect effects via head weight were positive and significant. Large amounts of additive gene action were observed in the expression of plant height. This trait was also highly negatively correlated with harvest index; therefore, phenotypic selection for restricted plant height would be useful in obtaining lines with high grain to straw ratios. In general, crosses that showed high specific combining ability effects involved parents with low general combining ability. However, there were some exceptions to this rule. Crosses of high x high and high x low general combiners presented high specific combining ability effects, suggesting that some additive gene action may be involved in the superior performance of these combinations. Also the F 2 generation did not differ from the F1 in assessing general cornbining ability. A wheat breeder should be aware of those genetic associations between agronomic traits that could be used to select superior cultivars. However, the genetic correlations in this study suggested that each cross represented a different set of gene associations depending upon the parents involved. If some progress is to be made in using the genetic variability available in the crop, the breeder should not try to select exactly the same type of plant from every cross. Every hybridization is potentially a source of better lines if they are well planned and the reasons they were made are remembered during selection. It is very important to realize what are the contributions of each parental line in a cross and what are the most important trait associations present in each parent. Superior rural genetic variability existing in the crop.

Download or read book Acta Agronomica Hungarica written by and published by . This book was released on 1986 with total page 906 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Ninth Regional Wheat Workshop written by and published by CIMMYT. This book was released on 1996 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Analysis of the Effectiveness of Selection in Early Generation Trials for Grain Yield of Wheat Triticum Aestivum L Em Thell written by Ross Forrest Gilmour and published by . This book was released on 1988 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparison of Four Methods of Selection for the Imnprovement of Grain Yield in Winter by Spring Wheat Crosses Triticum Aestivum L Em Thell written by Guillermo Oritiz Ferrara and published by . This book was released on 1981 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulgarian Journal of Agricultural Science written by and published by . This book was released on 1997 with total page 860 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 822 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nature of Inheritance and Association of Time Duration and Rate of Grain Filling and Subsequent Grain Yield in Crosses of Winter and Spring Wheats Triticum Aestivum L Em Thell written by Byung Han Choi and published by . This book was released on 1983 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature of inheritance and possible associations for traits influencing earliness and grain yield were investigated using a four parent diallel of winter and spring wheat cultivars. More genetic variability was observed for the traits measured in segregating populations resulting from crosses between winter and spring type wheats in contrast to spring x spring or winter x winter crosses. The one exception was plant height where more genetic variability resulted from spring x spring crosses. Narrow sense heritability estimates were high for time and duration of heading, anthesis, grain filling and physiological maturity and for plant height. Smaller values were noted for rate of grain filling, kernel number, harvest index, tiller number, kernel weight, whole plant dry weight and grain yield. Estimates of the coefficient of heritability and the parent-offspring correlation coefficient were similar in magnitude except for the traits grain yield, tiller number, kernel weight and whole plant dry weight where large variations due to the environment were encountered. Using the Jinks-Hayman model, no maternal effects were noted nor were any nonallelic interactions observed for total duration of grain filling and lag period. The actual grain filling period was influenced to some degree by such interactions. The spring cultivars also appeared to have more dominant genes for longer total duration of grain filling and lag period. In contrast the winter parents had more dominant genes for the longer actual grain filling period. Estimates of general and specific combining ability provided similar evidence in terms of the nature of gene action. Both additive and nonadditive gene action was present for all traits, the relative magnitudes depending on the specific trait. Based on individual combining ability effects, the winter x spring cross Yamhill x Siete Cerros would appear to provide the highest proportion of desired segregates when combining earliness and acceptable grain yield. From the direct and indirect associations of grain yield, it would appear that a shorter duration of grain filling along with a shorter lag period from heading to anthesis are important for higher rates of grain filling if negative associations between earliness and grain yield are to be avoided.