KY Public

In the present investigation, in vitro tuberization, pre treatments for improvement of seed germination, potting media for seedling establishment and influence of growth regulators on sprouting of tubers were studied.

In the in vitro techniques, tuber node was used as explant for the micro tuber formation. Explants sterilized with 70% ethanol for 30 seconds and HgCl2 for 60 sec reduced the contamination percentage (8.00%). MS medium supplemented with 4.0 mgl-1 BAP and 1.0 mgl-1 NAA recorded the highest response for primary tuber (100 %) and secondary tuber (100 %) formation. Minimum number of days for primary (19.88 days) and secondary tuber (45.11 days) formation was recorded in the medium supplemented with 4.0 mgl-1 BAP and 1.0 mgl-1 NAA. This also recorded the maximum number of tuber (1.77) from single explant. GA3 (1.0 mgl-1) was observed to be vital for the elongation of shoot where as IAA (1.0 mgl-1) in combination with IBA was effective for induction of roots on MS medium.

Seed germination is erratic due to the presence of hard seed coat and hence germination is very poor. The studies on seed treatments revealed that, pre treating the seeds with hot water for an hour improved the germination (34.88%) and also resulted in earlier germination (48.35 days) of seeds.

With reference to different media, the combination of sand, soil, cocopeat (2:2:1) recorded better seed germination and early germination and was very effective for micro tuber development. At 150 days after sowing, this medium gave the maximum length of the micro tuber (2.84 cm), fresh weight (1.76 g) and dry weight (1.25 g) of the micro tuber while sand:soil:FYM recorded the maximum girth of the micro tuber (3.29 cm).

Tubers treated with different growth regulators to enhance the sprouting, indicated that ethrel (500ppm) contributed for maximum sprouting percentage of tubers (100%), earlier sprouting (6.33days), maximum plant height (99.32cm) and maximum number of leaves (34.04).