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 primary regenerants of a tall traditional-salt tolerant indica cultivar Pokkali from mature seed-derived calli through in vitro culture. Twenty-six promising 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 conditions in SC3 and SC4 generations. Ten lines were ultimately found to be promising which could be tested to assess their adaptability across the rice-growing areas of the country. The present paper summarises genesis, selection strategy adopted and the detailed dossier of the selectants. Major agronomical traits, grain quality parameters and SDS-PAGE profile of salt-soluble grain polypeptides of the selectants revealed their remarkable genetic divergence from parental base populations. This shows that rice improvement through somaculture shows promise and is accessible to all plant breeders. (C) 1999 Elsevier Science B.V. All rights reserved.