Random Amplified Polymorphic DNA Studies in Cotton
Oct 8, 2018
Polymerase chain reaction (PCR)-based random amplified polymorphic DNA (RAPD) analysis can to be an important tool in the hands of plant breeders. Among its many applications, RAPD analysis can be used to measure genetic diversity and for DNA fingerprinting. In this investigation, 22 genotypes, representing cultivated Gossypium hirsutum, G. barbadense and G. arboreum with diverse morphological traits and one wild species G. thurberi, were subjected to RAPD analysis using 20 random 10-mer primers. DNA was extracted and quantified by established methods for RAPD analysis and the PCR conditions were standardized. Eleven primers produced 128 amplification products of which 119 (92.97%) were polymorphic between at least two of the entries. The size of the amplification products ranged between 201 and 2888 bp. Specific markers were observed for each of the four species. A set of five primers distinguished all 23 genotypes. Five cultivar-specific markers were also observed. A dendrogram constructed from the RAPD data classified all the genotypes into two broad clusters of wild and cultivated species. The cultivated species were further classified into G. arboreum, G. hirsutum and G. barbadense clusters. The wild species (G. thurberi), which fell away from the cultivated species, was about 18 percent similar to them. The similarity of the G. arboreum and G. hirsutum clusters was 47 percent. Gossypium thurberi appeared to be more closely related to G. barbadense than to the other two cultivated species.