S.REVATHI AND M.ARUMUGAM PILLAI
Abstract
Tissue culture techniques can be used as a source for genetic variability by means of genetic modifications through the process of in vitro cultures. This technique has been widely used for breeding purposes, especially for stress tolerance selection, which severely limits the rice production. In the present study, performances of rice genotypes were analyzed using different concentrations of Sodium Chloride (NaCl). Four rice genotypes viz., ADT 43, ASD 16, Basmati 370 and Pokkali were used for in vitro stress induction study. Callus was initiated in MS medium with 2 mg/l 2,4-D and different concentration of NaCl viz., 0.5, 1.0, 1.5 and 2.0 per cent were added with the medium to create salt stress. Statistical analysis revealed that all the genotypes and treatments and their interaction effect were significantly different from each other. Among the four genotypes studied Pokkali was significantly superior for callus induction with 50.19 per cent followed by ASD 16, ADT 43 and Basmati 370 with 46.74 per cent, 43.56 per cent and 33.27 per cent respectively. When the callus for genotypes were transferred to regeneration media in the same level of NaCl stress (0.5, 1.0, 1.5 and 2.0 per cent) highest level of regeneration was realized in Pokkali (56.93 per cent) followed by ASD 16 (53 per cent), ADT 43 (47.93 per cent) and Basmati 370 (40.07 per cent). Similar trend was also observed for salt stressed callus proline content. This proline content analysis further suggests potential salinity tolerance in the rice genotypes.