MOLECULAR DIVERSITY ANALYSIS AND POLYMORPHISM STUDY IN COTTON (Gossypium hirsutam L.) GENOTYPES THROUGH RAPD MARKERS

Abstract

The experiment was conducted at the Laboratory of the Department of Biotechnology, Sher-eBangla Agricultural University (SAU), Dhaka- 1207, Bangladesh. The period of the experiment

was

March 2018 to November 2018. Cotton (Gossypium hirsutum L.) is the leading fiber crop and the second most important oil seed crop in the world. This study aimed to analyze the molecular diversity among 9 cotton genotypes collected from Cotton Development Board, Bangladesh using the Random Amplified Polymorphic DNA primer. A total of 11 RAPD primers were used to determine polymorphism among the genotypes and finally 6 of the primers produced scorable DNA bands. Some total of with 30 DNA bands were obtained and among them 9 were polymorphic bands. The ranged of DNA amplification varied from 160 to 1500 bp. The rate of polymorphism was calculated about 31.57%. Genetic diversity ranged from 0.22 to 0.44 with an average value of 0.30. Nei’s genetic distance ranging from 0.1667 to 0.6667 and most importantly PIC value ranged from 0.18 to 0.35 with an average value of 0.27. The PIC value indicates that most of the studied cotton genotypes was moderately diversified and homogenous as well as no heterozygosity found. A dendogram indicating the relative genetic similarity of the Bangladeshi cotton genotypes was constructed which followed in two major cluster (A and B) among the studied material. The results also showed that the genotypes can be separated from each other at the molecular level by taking advantage of some of the RAPD markers. The Cotton Development Board, Bangladesh committed to work on cotton improvement and so for this was the first time in CDB to investigate molecular diversity and DNA profiling in cotton using CDB collected cotton genotypes. This experiment can be used as a baseline for the future molecular research work on cotton genotypes in Bangladesh.