Genetic Diversity in a Part of Bread Wheat Germplasm of National Plant Gene Bank of Iran

This research was performed to study the genetic diversity of 470 accessions of bread wheat collection of National Plant Gene Bank of Iran. The experiment was conducted in an augmented design in Karaj, Iran in 2012-2013 cropping season. The agronomic and morphological traits were assessed according to International descriptor and genetic diversity in germplasm was investigated by descriptive statistics. Among the qualitative traits, spike density had the highest variation based on Shannon index (0.903). Grain weight of five spikes and grain number per spike had the highest coefficient of variation and diversity among quantitative traits. Grain weight of five spikes had the highest significant positive coefficient of correlation (r = 0.69**) with number of grains per spike and had also significant positive correlation with spike length, 100grain weight, stem diameter, number of spikelets per spikes and number of flowerlets per spikelets. The results of principal component analysis showed that the first five principals justified 68.3% of total variation. Cluster analysis by K means method placed the accessions in ten groups. The first group had the highest mean of grain weight of five spikes, number of grains per spike, number of flowerlets per spikelet, number of spikelets per spike and had the largest distance to other groups. The superior accessions like 5617 (Iran) with grain weight of five spikes of 26.55g, 5752 (Afghanistan) with 100grain weight of 6.7g, and 6783 (China) with 103.4 grains per spikes, could be utilized as valuable resources for the evaluated traits in future breeding programs.