Salt-tolerant Pokkali somaclones: performance under normal and saline soils in Bay Islands

Profitable exploitation of somaclonal variation in crop improvement is well documented (Karp, 1995). To exploit the same in rice, we generated 1190 pr imary regenerants of a tall traditional-salt tolerant indica cultivar Pokka li from mature seed-derived calli through in vitro culture. Twenty-six prom ising plants were initially chosen from approximately 35 000 SC2 segregants , which were further evaluated under intense selection pressure both in the laboratory (under hydroponics with excess salt stress) and in field condit ions in SC3 and SC4 generations. Ten lines were ultimately found to be prom ising which could be tested to assess their adaptability across the rice-gr owing areas of the country. The present paper summarises genesis, selection strategy adopted and the detailed dossier of the selectants. Major agronom ical traits, grain quality parameters and SDS-PAGE profile of salt-soluble grain polypeptides of the selectants revealed their remarkable genetic dive rgence from parental base populations. This shows that rice improvement thr ough somaculture shows promise and is accessible to all plant breeders. (C) 1999 Elsevier Science B.V. All rights reserved.