1771 ANALYSIS OF GENETIC DIVERSITY IN COTTON (GOSSYPIUM HIRSUTUM L.) VARIETIES USING AMPLIFIED

Morphological markers in cotton are few and provide the general representation of the cultivars according to their growing environments. Molecular markers are numerous and do not effect phenotypes. Amplified Fragment Length Polymorphism (AFLP) analysis has proved powerful for identification of large numbers of potential polymorphic loci in diverse cotton germplasm. In Tanzania morphological characters had been used to study genetic diversity among cotton material. AFLP was used to assess genetic diversity among 26-selected cotton (Gossypium hirsutum L.) cultivars from Tanzania (local and exotics) where eight informative AFLP primer combinations were used. NTSYS-pc software was used to determine genetic similarities and construct a dendrogram. Polymorphic information content values (PIC) calculated to study the capacity of the primer combinations in amplifying polymorphisms in cotton cultivars. Results indicated that primer combinations used had high PIC values (0.37 to 0.57) and could discriminate between cultivars. Genetic similarity between all cultivars based on Dice similarities ranged from 0.894 to 0.979 with total average of 0.939. Dendrogram indicated narrow genetic diversity in Tanzanian cotton cultivars. Molecular data confirmed pedigree and origin, meaning that many cultivars were closely related. Heterotic groups were not of much diverse except for Delcot 344, which was very different from others. The study on genetic diversity for more material has to be done. Diverse cultivated cotton cultivars have to be introduced to increase the cotton genetic base in Tanzania