Genetic diversity analysis of various red spider miteresistant upland cotton cultivars based on RAPD

This study is carried out to analyze the genetic diversity of red spider mite-resistant cotton ( Gossypium hirsutum ) cultivars that are applied in cultivar identification and breeder's right protection of cottons. The genomic DNA was used as template and random primers were used to analyze the genetic diversity of 21 accessions of Gossypium hirsutum by RAPD-PCR. Among the 100 primers screened, 20 primers could generate 176 fragments, 96.02% of which were polymorphic ones. The similarity coefficient of cultivars was between 0.2273 - 0.9773. The average values of effective number of alleles, Nei’s gene diversity and Shannon’s information index were 1.7391, 0.4017, and 0.5773, respectively. Cluster analysis based on UPGMA revealed that 21 cultivars could be divided into three groups. The analysis revealed that it was corresponding to the geographical distribution and most of the lines had a wide genetic base. Key words : Cotton, red spider mite, RAPD, genetic diversity, cluster analysis