GENETIC DIVERSITY ASSESSMENT OF COMMON WINTER WHEAT (TRITICUM AESTIVUM L.) GENOTYPES
The knowledge about of genetic diversity of common winter wheat (Triticum aestivum L.) genotypes is useful for production of more efficient crops adapted to diverse conditions. A set of 32 common winter wheat varieties was used to estimate and then utilize the genetic diversity between common winter wheat genotypes by using cluster analysis and factor analysis and to identify effective factors on genetic improvement. Eight agronomic traits were included in the study. The GCV values were lower than PCV values for all the traits. High genetic advance combined with high heritability showed characters: plant height and spike length. Cluster analysis based on ward's method using Euclidian distance, grouped the cultivars into four clusters. Genotypes in the second group were in the highest rate with respect to number of productive tillers per plant, number of spikelets per spike, number of grains per spike, grain weight per spike and yield per plant. Principal Component analysis was applied to group accessions according to similarity on the basis of eight traits in tree components in the factor plane. The first three components explained 82.63% of total variation in the experiment. Cluster analysis based on the three factors grouped the varieties into four clusters. Genotypes of the first cluster can be used for increase in number of productive tillers per plant in breeding programs. Genotypes of the second cluster can be used for increase in thousand grain weight. Genotypes in the fourth cluster had highest mean with respect to first factor and can be used for increase in number of grain per spike.