Genetic diversity analysis of the species of Gossypium by using RAPD markers

Random Amplified Polymorphic DNAs (RAPDs), a DNA polymorphism assay based on the amplification of random DNA segments with single primers of arbitrary nucleotide sequence, was utilized to measure the genetic distance among the species of Gossypium. Variations among 20 different species of Gossypium were analyzed with 63 random 10-mer primers using the polymerase chain reaction (PCR). Out of a total of 370 RAPD bands generated from the 20 wild species, 310 were perceived polymorphic. The study detected a high level of genomic variability of the species of Gossypium. The maximum similarity of 64% was observed between Gossypium arboreum and Gossypium herbaceum and minimum similarity of 3% was observed between Gossypium stocksii and Gossypium longicalyx. Cluster analysis by the unweighted pair group method of arithmetic means (UPGMA) showed that 20 wild species can be divided into several groups, although it is believed that Gossypium is a very widely distributed, wild species having being discovered in all the continents of the world which extends into the subtropical region. The relationship among the species is presented in the dendrogram.