Muhammad, Subhan (2002) GENE ACTION AND COMBINING ABILITY STUDIES OF SOME QUANTITATIVE PARAMETERS IN GOSSYPIUM HIRSUTUM L. PhD thesis, Gomal University, D.I. Khan.
Diallel cross analysis experiment of eight varieties/strains of Upland cotton Gossypium hirsutumL. viz: CYTO 9/91, B-496, SLS-1, NIAB-78, NIAB-313/12, B-622, NIAB-92 and CYTO-11/91 was launched at experimental area of the Department of Plant Breeding and Genetics, Faculty of Agriculture, Gomal University, Dera Ismail Khan, Pakistan, during the years 1996-1999. The parents were genetically analyzed to study gene action and combining ability controlling the phenotypic expression of characters and screened out flexible parental lines which could be used in any hybridization strategy to produce germplasm with attractive genetic makeup. The analysis of variance illustrated that the differences among the genotypes for all characters were highly significant both in F1 and F2 generations. The Hayman-Jinks model proved to be adequate for five characters like height of main stem, number of bolls plant-1, lint percentage, seeds boll-1,staple length in F1 and five parameters i.e., height of main stem, number of bolls plant-1, seed index, lint index, staple length in F2 generations respectively. The additive dominance model for characters like yield of seed cotton plant-1, boll weight, seed index, lint index in case of F1 population while for yield of seed cotton plant-1, boll weight, lint percentage and seeds boll-1 were partially adequate in F2 population respectively. Furthermore, it was also observed that there did not expose any character which could render the model inadequate in both the generations. In contrast, it was signified that genes acting additively were more obvious than genes acting non-additively. The graphic expression of variance (Vr) and covariance (Wr) exposed that genes acted additively with over dominance in various characters like height of main stem, number of bolls plant-1, and yield of seed cotton plant-1 land boll weight. But genes acted additively with partial dominance in case of lint percentage, seeds boll-1 along with complete dominance for seed and lint indices were exposed in the genetic control of F1generation. On the other hand the involvement of additive with partial dominance type of gene action was accomplished in the genetic control of all the characters in F2 generation. This nature of genes and exploitation of heterosis are clearly valuable for the upgrading of hybrid plant material which may be used for increasing yield and its components of cotton. The combining ability analysis studies uncovered that the partitioning of the variance into its components exhibited that specific combining ability variance was greater in magnitude and more outstanding for the characters like yield of seed cotton plant-1, number of bolls plant-1, seed index, lint index and staple length resulting thereby the inheritance of non additive type of gene action involved in the expression of these characters. Likewise, the general combining ability variance was greater in magnitude and more attractive for lint percentage and number of seeds boll-1 indicating thereby the involvement of additive type of gene action in the expression of these traits. The best general combiners like NIAB-78 was confirmed for the characters like lint percentage and lint index while NIAB-3l3/12 was exposed in case of bolls plant-1, yield of seed cotton plant-1 and boll weight. NIAB-92 was clarified as the best general combiner for the trait like staple length. Keeping in view the results of the combining ability analysis study it is, therefore, strongly suggested that the bolls plant-1, yield of seed cotton plant-1,boll weight, lint percentage and staple length may be made the criteria for selecting high yielding genotypes with attractive quality of cotton under the limits of this experiment.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Gene action, Combining ability, Gossypium L, CYTO 9/91, B-496, SLS-1, NIAB-78, NIAB-313/12, B-622, NIAB-92, CYTO-1/91, Number of bolls plant-1, Lint percentage, seeds boll-1, Staple length,|
|Subjects:||Agriculture & Veterinary Sciences(a)|
|Deposited By:||Mr Ghulam Murtaza|
|Deposited On:||21 Jun 2006|
|Last Modified:||22 Jan 2009 21:11|
Repository Staff Only: item control page