Qurban Ali

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

Several wheat genotypes were screened against heat stress. Seven wheatn( Triticum aestivum L.) cultivars obtained after screening againstnheat classified as tolerant, moderately tolerant, and susceptible tonheat stress, were mated in a complete diallel mating system to studynthe inheritance pattern of relative cell injury percentage (cell injuryn%) and some yield contributing parameters under normal and heat stressnconditions. Significant genotypic differences were found (P < 0.01)nfor all the studied traits under both regimes. The scaling testndisclosed partial adequacy for traits such as days to heading and daysnto maturity, but for flag leaf area and relative cell injury %, itnshowed full sufficiency under both environments. The model for grainnyield per plant and biomass per plant were fully adequate under normalnconditions, but partially adequate under stress. The harvest indexnshowed partial adequacy under normal conditions, but was fully adequatenunder stress. The additive component of genotypic variation (D) wasnsignificant for all studied traits and more significant than the H1 andnH2 dominance components. Values of the gene proportion with positivenand negative effects in the parents (H2/4H1) demonstrated an unequalndistribution of dominant genes in the parents for almost all the traitsnexcept for flag leaf area, grain yield per plant, and harvest indexnwhich showed an equal distribution of dominant genes under stressnconditions. High heritability estimates were found for days to heading,ndays to maturity, flag leaf area, grain yield, and relative cell injurynpercentage under both regimes. Moderately high estimates were found fornbiomass per plant and harvest index.

Multivariate Analysis of Grain Yield and Its Attributing Traits in Different Maize Hybrids Grown under Heat and Drought Stress

This study was carried out to evaluate F1 single cross-maize hybrids in four crop growing seasons (2010–2012). Morphological traits and physiological parameters of twelve maize hybrids were evaluated (i) to construct seed yield equation and (ii) to determine grain yield attributing traits of well-performing maize genotype using a previously unexplored method of two-way hierarchical clustering. In seed yield predicting equation photosynthetic rate contributed the highest variation (46%). Principal component analysis data showed that investigated traits contributed up to 90.55% variation in dependent structure. From factor analysis, we found that factor 1 contributed 49.6% variation (P < 0.05) with primary important traits (i.e., number of leaves per plant, plant height, stem diameter, fresh leaves weight, leaf area, stomata conductance, substomata CO2 absorption rate, and photosynthetic rate). The results of two-way hierarchical clustering demonstrated that Cluster III had outperforming genotype H12 (Sultan × Soneri) along with its most closely related traits (photosynthetic rate, stomata conductance, substomata CO2 absorption rate, chlorophyll contents, leaf area, and fresh stem weight). Our data shows that H12 (Sultan × Soneri) possessed the highest grain yield per plant under environmentally stress conditions, which are most likely to exist in arid and semiarid climatic conditions, such as in Pakistan.