EFFECT OF POTASSIUM ON POTATO MICROTUBER PRODUCTION IN-VITRO

The role of potassium nutrition in microtuber production was investiga ted in two potato cultivars belonging to different maturity groups. Al terations were made in Murashige and Skoog (MS) medium to obtain seven concentrations of potassium (10, 15, 20, 25, 30, 35 and 40 mM), and t heir effects were studied on microtuber number, microtuber mass and ha rvest index. In late cultivar Kufri Sindhuri, an increase in potassium concentration beyond 25 mM decreased the number of microtubers, Where as, potassium did not show any inhibitory effect on microtuber number in early cultivar Kufri Ashoka, Potassium showed promoting effect on m icrotuber mass in both the cultivars, Maximum microtuber mass and harv est index were observed when the medium was supplemented with 30 mM po tassium. Therefore, large size potato microtubers amenable to direct f ield planting can be induced in MS medium containing 40 mM potassium.