Factor analysis and cluster analysis for grain yield and some important agronomic characteristics in spring bread wheat genotypes under terminal drought stress and non-stress conditions

Some of the important agronomic characteristics were evaluated in 50 spring bread wheat genotypes under terminal drought stress and non-stress conditions-using alpha-lattice design with two replications. The experiments were carried out in Experimental Field Station, Seed and Plant Improvement Institute, Karaj, Iran, in 2009-2010 cropping season. Measured traits, including maturity, maturity, days to anthesis, days to heading, grain filling rate, grain filling duration, plant height, length, second internode length, bulge out peduncle, peduncle length, spike length, grain weight a spike, grain number per spike, harvest index, seed weight, ear number per square meter, biological yield, grain yield, respectively. Terminal drought stress conditions and stress analysis of variance showed a significant difference between the yield on the 1% level is. Factor analysis based on principal component analysis and varimax rotation showed that first six factors overall justified 74.96% of variations in the studied variables and explained 77.03% of all observed variation in non-stress conditions. Simple correlation coefficients were calculated stress conditions indicate that the most positive and significant correlation with grain yield to biological yield and related traits in non-stress test spike is square. Cluster analysis was performed based on UPGMA method to classify the genotypes resulting in 5 and 4 groups in response to drought stress and non stress condition respectively.