Investigating Genetic Diversity Among Cotton Genotypes Available in the Iranian Gene Bank (Gossypium sp.) Using ISSR Molecular Marker

Cotton is one of the most important world crops and is considered as a major cash crop in the North East of Iran. All selections in plant breeding are based on diversity and an increase in genetic diversity determines the range of selection. In the present study، 24 cultivars of cotton available at the research station for cotton in the East of Iran -Kashmar- were studied using the ISSR marker. A total number of 13 primers، with repeated simple sequences، were used for the amplification of genomic DNA. Overall، 128 bands were obtained، 109 of which showed polymorphism. To evaluate genetic similarity between cultivars، cluster analysis accompanied by the similarity coefficient developed by Jaccard and Nee (1972)، were applied using the UPGMA method. Dendrogram analysis showed a high diversity in the cotton cultivars and two main groups with 70 percent genetic similarity dividing the cotton cultivars into two main groups; namely، tetraploid and diploid. The highest polymorphism percentage was related to 5'' (CT) 8RC3'' (100%) and the lowest belonged to 5'' (AG) 8YA3'' and 5'' (TC) 8G3'' (25%) primers. Based on the similarity matrix، the highest genetic similarity was found in Varamin and Khordad and the lowest in Avangard and Bakhtegan cultivars. Based on the obtained results، ISSR markers can be efficiently used for the investigation of genetic diversity among cotton cultivars.