COMPARISON AMONG DIFFERENT COTTON (GOSSYPIUMHIRSUTUM L.) GENOTYPES WITH RESPECT TO MORPHOLOGICAL, FIBRE QUALITY ATTRIBUTES AND EXPRESSION ANALYSIS OF CRY1AC GENE

Cotton is a cash crop of Pakistan and it plays a key role in the economy of the country for earning of foreign exchange. American cotton (Gossypium hirsutum L.) is the highest fibre producing specie of the world. The present study was conducted to check the comparison of morphological data, fibre quality traits and expression analysis of CrylAc gene in 14 cotton genotypes including hybrid (FI), F2 and F4 stages progeny m comparison with check variety MNH-886 at National Agricultural Research Centre, Islamabad during the year 2015 and 2016. The results of morphological traits revealed that field grown cotton genotypes showed variation in morphological characters. The highest plant height was observed 141.6 cm in HSP 7-4(2). Similarly, both maximum number of bolls per plant 115.60 and boll weight 5.92 g was reported in cotton hybrid NIGAB-4 respectively. The best internodes distance 2.32 cm was recorded in B-318-A genotype. There were significant differences observed in morphological traits of cotton except some genotypes. The results of fibre quality traits illustrated that optimum fibre fineness 3.1 mu g/inch was reported in cotton hybrid NIGAB -4. While the best results of fibre strength 28.6 g/tex was measured in HSP 7-4(2) and hybrid NIGAB-3, length 33 mm in NIGAB-4, uniformity ratio 49.4 % in NIGAB-4 and fibre elongation 12.9 % was recorded in Bl-37 genotype respectively. Meanwhile different Bt genes in 14 cotton genotypes (CrylAc, Cry2Ab and Cry lF genes) were checked through immunostrip assay and hence only Mon531 event for CrylAc gene of 346 bp was confirmed after immunostrip and PCR analysis. Quantification of CrylAc toxin was performed through sandwich ELISA at 80 and 120 days after sowing of leaf and boll tissues of 14 cotton genotypes. The CrylAc toxin level of these genotypes is in the range of 0.27 to 3.67 mu g/g based on fresh weight tissues. From the results, it has been concluded that cotton hybrids have performed well as compared to other tested cotton genotypes.