TRACING THE DIVERSITY OF CULTIVATED TRANSGENIC COTTON IN PAKISTAN BY SSR BASED DNA FINGERPRINTING

The introduction of transgenic Bacillus thuringiensis (Bt) cotton is one of the success stories of applying biotechnology in agriculture. It also decreased the use of insecticides and the production cost as an environmental and economic benefit, respectively. The use of selective genotypes as a parental material for Bt cotton breeding has resulted in the multiplication of limited germplasm. The main objective of the study was to find out the genetic diversity of cultivated Bt cotton genotypes by fingerprinting. Twenty-two SSR markers were used to analyze the genetic differences in Bt cotton genotypes, collected from two different sources i.e., research institutes and open market. Results showed that the Polymorphism information content (PIC) value ranged from zero to 0.673. A UPGMA based dendrogram divided all the genotypes into four main clusters. Eighty-six percent similarity was observed between VH-282 and AS-01 while the lowest similarity of 45% was found between IUB-222 and FH-167.This diversity of newly introduced transgenic genotypes will help to detect the diverse lines to be used in future for broadening the genetic base of Bt cotton in Pakistan. Another observation was that a genotype, FH-114 oBtained from two sources was clustered in two different clades. This showed the presence of name variants for a particular genotype depicting adulteration of seed available in seed market which need to be addressed. Though the adoption of Bt cotton was rapid, but the economic impact of this adoption was not significant in Pakistan as compared to other developing countries. The identified problem might be one of the reasons, limiting the benefits of this technology to be harvested out of it.