Determination of efficiency of some physiological traits on final grain yield in bread wheat and efficiency of these traits for selection of tolerant genotypes in rainfed condition

This study carried out for investigation of pre-anthesis and post-anthesis assimilates translocation from shoot to grain and Contribution of these traits in bread wheat yield in rainfed condition as well as relationship between these traits with bread wheat yield and their drought resistance. Seven genotype were investigated in one experiment using of randomized complete blocks design with four replicates in rainfed condition during 2006- 2007 years. Sampling were carried out in anthesis stage، 14 day after anthesis and physiological ripening. Grain yield، Biomass، Harvest index، Remobilization، Retranslocaton and Redistribution Percent and contribution of pre-anthesis and post-anthesis reserved assimilates in shoot to grain was determined. According to main resource of yield suppling، Postanthesis current photosynthesis in grain yield computed. Results showed that there is significant and positive phenotypic correlation between yield with Biomass، harvest index and current photosynthesis while there was significant and Negetive phenotypic correlation between yield with Remobilization and Redistribution. Based on factor analysis، tow first factor explained 83. 5% of total variance. First factor was explained by Current photosynthesis، biomass، Dry matter amount of shoot during physiological maturity and grain yield and Higher photosynthesis that was mean reduction of redistribution. As well as cluster analysis is based on ward method and placed genotypes in three separate cluster.