Akram, Zahid (2004) GENETIC IMPLICATION OF QUALITY AND YIELD CONTRIBUTING CHARACTERISTICS IN WHEAT. PhD thesis, University of Arid Agriculture, Rawalpindi.
Twenty five wheat genotypes were evaluated for different yield and quality related attributes at University of Arid Agricultural, Rawalpindi. The main aim of the study was to determine the nature of gene action and association between certain yield and quality characteristics in spring wheat. Medium to high variances were exhibited by the traits like days to heading, plant height, number of tillers m-2, flag leaf area, grain filling period, 1000 grain weight, grain yield and gluten contents indicating a good scope for improvement in these traits. Multivariate analysis was conducted using 25 wheat genotypes. The genotypes included in the study were grouped into three clusters on average linkage basis. First cluster comprised of 13 wheat varieties. In the second cluster, there were 11 varieties while there was only variety in the third group. Eight promising genotypes were selected from these clusters. In order to ascertain the gene action involved in the inheritance of these characters, the techniques like analysis of variance of Hayman model , genetic component analysis and Wr Vr graphic analysis were employed. The estimates of components of genetic variation showed that additive genetic effects controlled the expression of traits like days to heading, protein contents and flour yield, however, non additive gene effects were more important for days to maturity, plant height, number of tillers m-2, flag leaf area, grain filling period, spike length, number of spikelets spike -1, number of grains spike 1 , 1000 grain weight, grain yield plant 1, lysine contents and gluten contents. Directional dominance was observed in case of plant height, number of grains spike 1, 1000 grain weight and protein contents which indicated the better chance of improvement in these traits. The graphic analysis revealed the presence of partial dominance for days to heading, protein contents and flour yield, while over dominance for rest of the traits studied. Days to heading, protein contents and flour yield being controlled by additive genetic effects with partial dominance suggested that selection can be practiced in early segregating generations for improvement in these traits. The results of the genotypic and phenotypic correlations in F2 progenies revealed that most of the traits showed significant and positive relationship with grain yield, except plant height, number of tillers m-2, protein contents and lysine contents where the association was negative. The path coefficient analysis revealed that days to heading, grain filling period and 1000 grain weight were important direct contributors towards grain yield. The selection on individual plant basis for these parameters may be beneficial for improving yield in the plant material studied.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Genetic Implication, Triticum aestivum L, Heritability, Correlation , Path, Coefficient, Protein contents, Lysine contents, Wheat genotypes, Plant height, Number of tillers m-2, Flag leaf, Grain filling period, 1000 grain weight, Grain yield, Gluten contents, Hayman model, Protein contents, Flour yield, Phenotypic correlation, F2 progenies, Path coefficient analysis,|
|Subjects:||Agriculture & Veterinary Sciences(a) > Agriculture(a1) > Plant culture(a1.4)|
|Deposited By:||Mr Ghulam Murtaza|
|Deposited On:||04 Aug 2006|
|Last Modified:||11 Jun 2008 21:42|
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