Genetic Diversity and Relationships of Agronomic Characters in Wheat Recombinant Inbred Lines

Objective: Wheat is the most important crop in Iran. Self sufficiency in wheat production is one of the economic and food safety policies in the country. In spite of the efforts which have been made in this area, the mean of wheat yield in Iran is less than its world average. Methods: In order to identifying of the high yielding wheat lines with optimal characteristics and to determine the traits which could be used as the selection index for increasing of grain yield, 40 recombinant inbred lines derived from a cross between Norstar and Zagros cultivars were evaluated in a randomized complete block design with three replications. Results: Significant differences were observed among the lines for all of studied traits, except the spike weight, flag leaf area and the straw yield. Higher genetic diversity was observed among the inbred lines with respect to the kernel per spike, the number of spikes, the biomass and the straw yield. The Peduncle weight, second internode weight, number of kernels per spike per spike, number of the spikes and 1000 kernel weight traits showed a high degree of heritability. The highest genetic gain was estimated for the peduncle weight, the second internode weight and number of kernel per spike. Correlation, stepwise regression and path analyses revealed the number of kernels per spike and the number of spikes in plot had highest direct effects on grain yield. The analyses were carried out using WARD algorithm and standardized data. Cluster analysis based on all traits assigned the lines into groups.