Genetic Analysis of Relative Cell Injury Percentage and Some Yield Contributing Traits in Wheat Under Nomral and Heat Stress Conditions

Abstract

Several wheat genotypes were screened against heat stress. Seven wheat (Triticum aestivum L.) cultivars obtained after screening against heat classified as tolerant, moderately tolerant, and susceptible to heat stress, were mated in a complete diallel mating system to study the inheritance pattern of relative cell injury percentage (cell injury %) and some yield contributing parameters under normal and heat stress conditions. Significant genotypic differences were found (P < 0.01) for all the studied traits under both regimes. The scaling test disclosed partial adequacy for traits such as days to heading and days to maturity, but for flag leaf area and relative cell injury %, it showed full sufficiency under both environments. The model for grain yield per plant and biomass per plant were fully adequate under normal conditions, but partially adequate under stress. The harvest index showed partial adequacy under normal conditions, but was fully adequate under stress. The additive component of genotypic variation (D) was significant for all studied traits and more significant than the H 1 and H 2 dominance components. Values of the gene proportion with positive and negative effects in the parents (H 2 /4H 1 ) demonstrated an unequal distribution of dominant genes in the parents for almost all the traits except for flag leaf area, grain yield per plant, and harvest index which showed an equal distribution of dominant genes under stress conditions. High heritability estimates were found for days to heading, days to maturity, flag leaf area, grain yield, and relative cell injury percentage under both regimes. Moderately high estimates were found for biomass per plant and harvest index.

Estimation of heritability and genetic advance for various metric traits in seven F2 populations of bread wheat (Triticum aestivum L.)

“…High heritability and genetic advance estimates show that this trait can be improved through sensible selection among these crosses. The results of the present research are in agreement with the findings of Chowdhry et al (1997), Khan et al (2003), Ahmed et al (2004) and Farooq et al (2011).…”

Diallel Analysis of Some Important Grain Yield Traits in Bread Wheat Crosses

“…These findings correspond with the results published by other authors who also indicated over-dominance type of gene action in the inheritance of the trait grain weight per plant (Nazir et al, 2014;Yao et al, 2014;Shehzad et al, 2015). Contrary to these results, partial dominance in the inheritance of this trait was observed by Farooq et al (2011) and Rashid et al (2013).…”

Inheritance pattern of earliness and yield traits in half diallel crosses of spring wheat

“…Also, Asif et al (2000) and Pal and Kumar (2009) found that biological yield was managed by the overdominance type of genes in wheat and barley, respectively. A significantly higher value of additive than dominance genetic components indicated the additive type of gene action in controlling biological yield in wheat (Farooq et al 2011). A greater value of the average degree of dominance than unity was reported for biological yield in F 2 populations of wheat (Jadoon et al 2012).…”

“…Solomon and Abuschagne (2004) reported high heritability for days to heading, which might be due to the involvement of few major genes in durum wheat. High heritability was reported for days to heading in genetic analysis for earliness-and yield-associated traits in spring wheat under normal and stress environments (Farooq et al 2011).…”