Abstract

Cotton is one of the main economic crop plants of Iran cultivated under continuous artificial selection and cultivation which may lead to genetic erosion and possible loss of useful genetic loci resulting in vulnerability to pests and diseases. For this reason increasing and improving the amount of genetic diversity in cotton germplasm through tissue culture is important. The present report considers genetic diversity induced in tissue culture regenerated plants of three cotton cultivars namely Mehr, Sindose and their hybrid Mehr X Sindose. Surface of seeds were disinfected with 70% ethanol for 2 min and then treated with 5% hypochlorite solution for 20 min. Finally, they were washed 3 to 4 times with sterile distilled water and inoculated aseptically onMurashige and Skoog (MS) basal medium free hormones. Single nodes resulted from seedlings cultured as explants. Inter simple sequence repeat (ISSR) and simple sequence repeat (SSR) primers used produced different number of bands in the genotypes studied showing different levels of molecular polymorphisms in each cultivar. Some common and few specific ISSR/SSR loci were indentified while some bands were present in all the genotypes except one indicating genetic changes in them. Analysis of molecular variance (AMOVA) test showed significant difference (p < 0.05) for ISSR markers but not for SSR markers. Molecular trees obtained showed genetic variations among the regenerated plants of each cultivar due to tissue culture.

Key words: Cotton, genetic diversity, ISSR, RAPD.