Author: Surendra Prasad SinhaPublisher:
ISBN:
Category : Wheat
Languages : en
Pages : 80
Book Description
Specific Combining Ability Estimates in Winter Wheat Crosses
Author: Surendra Prasad SinhaPublisher:
ISBN:
Category : Wheat
Languages : en
Pages : 80
Book Description
Estimates of Heterosis and Combining Ability in Crosses Among Seven Hard Red Winter Wheat Varieties
Author: Young Woung LeeCombining Ability and Gene Action Estimates and the Association of the Components of Yield in Winter Wheat Crosses
Author: Warren Ervind KronstadPublisher:
ISBN:
Category : Hybridization
Languages : en
Pages : 128
Book Description
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.
Author: Publisher: INIAP Archivo Historico
ISBN:
Category :
Languages : en
Pages : 184
Book Description
Studies on Hybrid Vigor and Combining Ability in Wheat Diallel Crosses
Author: Daulat N. SajnaniPublisher:
ISBN:
Category : Plant hybridization
Languages : en
Pages : 316
Book Description
Heterosis, Inbreeding Depression and Combining Ability Estimates from Diallel Crosses in Hard Red Winter Wheat
Author: Young Woung LeeUse of Combining Ability Estimates to Identify the Genetic Potential of Selected Winter Parental Lines (Triticum Aestivum L.em Thell)
Author: Muhammad Shahid MasoodPublisher:
ISBN:
Category : Winter wheat
Languages : en
Pages : 340
Book Description
A major factor limiting the efficiency of plant improvement programs is the lack of knowledge as to which parental combinations to make when working with quantitatively inherited traits. The primary objective of this study was to provide information regarding the use of combining ability analysis to predict which cross combinations would result in the greater frequency of desirable segregates. Five winter wheat parents were used to develop a 5x5 diallel cross. Over a two year period parents, Fl, F2, F3, and F4 generations involving top cross populations were evaluated. Information was collected on an individual plant basis for seven traits: plant height, tiller number, spike length, spikelets per spike, biological yield, grain yield, and harvest index. Griffing's (1956) model 1, method 2 was used to estimate GCA and SCA in Fl and later generations. Narrow-sense heritability estimates were computed using regression in standard units across generations. Significant GCA estimates were obtained for most traits in all generations with the exception of tiller number and grain yield in the Fl during 1986-87. Specific combining ability estimates were also found to be important for all traits, except spikelets per spike in the Fl and F3 generations. High GCA to SCA ratios indicated a preponderance of additive gene action. Exceptions to the trend were grain yield and tiller number in the Fl during 1986-87. Low GCA and narrow-sense heritability estimates suggest that selection for these two traits would have to be delayed until later generations. When considered over generations, both GCA and SCA estimates were found to be significant. Significant SCA over generations indicated the presence of additive x additive epistasis. The GCA effects contributed by a particular parent were consistent over all generations indicating that F2 and F3 generations can be used effectively for combining ability analysis. However, the results did suggest that GCA estimates were more influenced by the environment than SCA. For the traits measured and in the populations used in this study, GCA effects did predict the best parental combinations for obtaining the highest percentage of desirable progeny in segregating populations.
AGRONOMIC, MILLING AND BACKING CHARACTERISTICS OF HYBRID SPRINGWHEATS (TRITICUM AESTIVUM L.)
Author: PABLO ENRIQUE LARREAPublisher: INIAP Archivo Historico
ISBN:
Category :
Languages : en
Pages : 69
Book Description
Agronomic, Milling and Baking Characteristics of Hybrid Spring Wheats (Triticum Aestivum L.)
Author: Pablo Enrique LarreaPublisher: INIAP Archivo Historico
ISBN:
Category : Wheat
Languages : en
Pages : 144
Book Description
Combining Ability Analysis of Anatomical Components of the Dry Fruit of Capsicum Annuum L
Author: Omar MarínPublisher:
ISBN:
Category : Capsicum annuum
Languages : en
Pages : 110
Book Description