Evaluation of Genetic Variability of Agronomic Traits in Iranian Wheat Landraces and Cultivars

In order to evaluate the genetic variability of Iranian wheat landraces and cultivars and to determine the relationship between grain yield and other traits, 313 Iranian wheat genotypes including 203 Iranian wheat landraces and 110 Iranian cultivars were planted in a three separated augmented design along with three check cultivars repeated in seven blocks in 2014 on the research field of Agronomy and Plant Breeding, University of Tehran. Results showed that there are significant differences among genotypes in the investigated traits. Based on the results of descriptive statistics, the landraces showed highly coefficient of variation in compare with the cultivars which reveals high phenotypic variation among the landraces. According to the results of phenotypic correlations, stepwise regression, path analysis, it can be concluded that the number of seed per spike, thousand seed weight and spike weight were the most important and effective traits affecting yield and considering that among genotypes, the biggest diversity were observed for these traits, therefore, selecting and breeding for these traits can ideally improve the grain yield. Based on cluster and canonical discriminant analysis, the investigated genotypes were grouped in three clusters. The most of the landraces were grouped in the first and third clusters and most cultivars were grouped in the second cluster which means during breeding programs, breeders have done selection for the investigated traits and it reveals the importance of these traits.