Effect of Genotype and Callus Induction Medium on Green Plant Regeneration from Anther of Nepalese Rice Cultivars

摘要

Effects of genotype and medium composition on the frequency of callus induction and green plant regeneration from anther of Nepalese rice were investigated. Cold pretreated anthers from six rice genotypes at 8±2°C for seven days were cultured on three different callus induction media designated as Callus Induction Medium (CIM 1): N6 mineral salts + N6 vitamins (2 mg L^-1 each) + myoinositol (100 mg L^-1) + 2,4-D (2.5 mg L^-1) + KI (0.5 mg L^-1) + AgNO₃ (10 mg L^-1) + maltose (50 g L^-1), CIM 2: N6 mineral salts + MS organic salts + NAA (4 mg L^-1) + Kinetin (KI) (2 mg L^-1) + Silver nitrate (AgNO₃) (5 mg L^-1) and sucrose 60 (g L^-1) and CIM 3: CIM 2 without AgNO_3.. The callus induction frequency was significantly affected by rice genotypes and genotype x medium interactions. The efficiency of callus induction (calli/anther) was higher in CIM 1 (14.1%) followed by CIM 2 (12.54%) and CIM 3 (10.3%). CIM 2 was found to be superior for the recovery of green plants. Among genotypes, only the calli from Chandanath -3 and Khumal-4 were able to differentiate into green plants. In this study the calli induced on medium containing 2, 4-Dichloroacetic acid (2, 4-D) had lower regeneration ability than the medium supplied with α-naptthalene acetic acid (NAA). This study also revealed that the temperate cultivars (hill rice) were more responsive to anther culture than the tropical ones (terai rice).