Investigation of Callus Induction Medium and Callusing Ability in Three Rice Varieties, viz, Ratnagiri-8, Karjat Shatabdi and Karjat-3

The present investigation was carried out in tissue culture laboratory at Plant Biotechnology Centre, College of Agriculture, Dapoli-Ratnagiri (M.H.) in Completely Randomized Design with 3 replications with the aim to set up the regeneration protocol in the three rice varieties, viz, Ratnagiri-8, Karjat Shatabdi, Karjat-3 with an objective to investigate suitable callus induction medium which can be used to develop an efficient in vitro regeneration technique through callus for the selected varieties. Mature seed embryo was used as explant for callus initiation.

The callusing ability of the varieties was tested on 12 media combinations with different concentrations of 2,4-D and NAA, their combinations and one control treatment. The highest callus induction was recorded for medium combination T2: MS + 2,4-D (2.0 mg/l) + NAA (0.5 mg/l) in Ratnagiri-8 and Karjat Shatabdi with a frequency of 66.67 % and 53.33 % respectively. Karjat-3 showed highest callus induction for medium combination T3: MS + 2,4-D (2.0 mg/l) +NAA (1.0 mg/l) with a frequency of 68.33 %. Similarly, the highest callus weight was recorded for T2 in Ratnagiri-8 (0.367 g) and Karjat Shatabdi (0.290 g) for T3 in Karjat-3 (0.392 g). Embryogenic, soft, friable callus with granular texture and yellowish white colour was obtained from all media combinations in all three varieties.