TISSUE CULTURE RESPONSES OF SOME WHEAT (TRITICUM AESTIVUM L.) CULTIVARS GROWN IN PAKISTAN

Good tissue culture response for callus induction and regeneration is prerequisite for improvement of wheat through genetic transformation. Tissue culture response of 6 wheat cultivars was studied using MS and N6 medium supplemented with different concentration of 2, 4-D (2,4-Dichlorophenoxyacetic acid) and BAP (6-benzylaminopurine) for callus induction and regeneration, respectively. Mature seeds were used as explants. All cultivars exhibited best response for callus induction and regeneration on MS medium as compared to N6 medium. However, significant differences among cultivars were observed. Each cultivar responded differently at different levels of growth regulator for callus induction. Inqalab-91 and Lasani-08 showed maximum callus induction (90%) and (78.78%), respectively at 3mg/l of 2, 4-D. Tatara showed 84.43% callus at 2.0mg/l, chakwal-97 77.08% at 2.5mg/l while GA-02 and Khyber showed 74.30% and 65.97% callus induction response, respectively, at 3.5mg/l of 2, 4-D. As regards regeneration, direct shoots and roots development were observed by using different concentration of BAP. Significantly higher regeneration (59.33%) was observed in Chakwal-97 with 3.0mg/l of BAP while least regeneration was observed in Khyber (17.33%) at 4.0mg/l among all cultivars. It was also observed that all cultivars showed shoot as well as root development with 3 and 5mg/l of BAP. Using 8mg/l agar rather than 6 and 10 mg/l significantly enhanced regeneration ability of cultivars. The results of present findings will be helpful for selecting the most tissue culture responsive cultivars for genetic transformation against different biotic and abiotic stresses as well as for improvement of important agronomic traits of wheat crop (Fig. 2).