Genetic variability assessment of Iranian wheat landraces in term of some agronomic attributes under normal irrigation and rain-fed conditions

In the current study, the genetic variability and effect of some agronomic traits on grain yield of 218 Iranian wheat landraces were evaluated under normal irrigation and drought stress conditions employing alpha-lattice design with two replications on the research field of Agronomy and Plant Breeding at the University of Tehran during the year of 2016-2017. Results of data analysis of variance demonstrated that there were significant differences among landraces in the investigated traits including phonologic and physiologic traits, yield and yield components in both conditions. According to descriptive statistics results, the highest phenotypic variation of landraces observed in seed number per spike, and the least variation in spike weight. The findings on phenotypic correlations, stepwise regression, and path coefficient analysis sustain the important role of spike weight, seed number per spike and thousand grain weight in the grain yield in both normal irrigation and rain-fed conditions. In addition, considered traits had the highest impact on the grain yield directly and indirectly under both conditions. The result of principle component analysis presented a positive correlation between the first component and seed number in both conditions, while the second component had a positive relationship with phonological traits in normal irrigation and leaf greenness in rain-fed conditions.