Response of four commercial potato cultivars to different combinations of plant growth regulators in meristem culture and production of virus free plantlets

Large amount of potato seed in the world is produced by in vitro virus free mini tubers. Therefore, evaluation of commercial varieties for production of virus free potato minituber is critical. In this study the effects of different hormones BA and KIN at three levels 0, 0.5 and 1 mgl-1 and GA3 at four levels 0, 2, 2.5 and 3 mgl-1 either alone or in combinations were evaluated in meristem culture of four potato cultivars; Agria, Marfona, Sante and Burren. Plantlets were sub-cultured into the semi-solid media including four hormones combinations of MS0 medium, MS medium containing 0.5 mgl-1 BA + 0.5 mgl-1 IBA, 0.5 mgl-1 IBA + 1.5 mgl-1 GA3 and MS medium containing 0.5 mgl-1 BA + 1.5 mgl-1 IBA + 2 mgl-1 GA3 to achieve the best medium for sub-culture. Then ELISA test was conducted and virus free plantlets were selected and transferred to the greenhouse. After 90 days, number of minitubers for each cultivar were counted and recorded. The best medium for primary establishment of meristem for Burren was MS medium containing 2 mgl-1 GA3, for Agria was MS medium containing 2.5 mgl-1, for Marfona and Sante the best medium was MS containing 0.5 mgl-1 KIN + 3 mgl-1 GA3. The best media for sub-culture of virus free plantlets for meristem culture for Burren, Agria and Marfona was semi-solid MS medium containing 1.5 mgl-1 IBA + 0.5 mgl-1 BA + 2 mgl-1 GA3 and for Sante was 0.5 mgl-1 IBA + 1.5 mgl-1 GA3. Marfona had the greatest and Agria the least number of minituber.