Towards salinity tolerance in Brassica: an overview.

Among the various abiotic stresses limiting the crop productivity, salinity stress is a major problem, which needs to be addressed and answered urgently. Since members of Brassicaceae are important contributor to total oilseed production, there is an immediate need being felt to raise Brassica plants which would be more suitable for saline and dry lands in years to come. One of the suggested way to develop salinity tolerant Brassica plants is to make use of the broad gene pool available within the family. Efforts of breeders have been successful in such endeavors to a large extent and several salinity tolerant Brassica genotypes have been developed within India and elsewhere. On the other hand, transgenic technology will undoubtedly continue to aid the search for the cellular mechanisms that confer tolerance, but the complexity of the trait is likely to mean that the road to engineer such tolerance into sensitive species will not be easy. However, with increasing number of reports available for suitable genetic transformation for various Brassica genotypes, there is a hope that salinity tolerance can be improved in this important crop plant. In this direction, the complete genome sequence of related wild plants such as Arabidopsis or crop plants such as rice can also serve as a platform for identification of "candidate genes". Recently, complete genome sequencing of the Brassica genomes has also been initiated with the view that availability of such useful information can pave way towards raising Brassica with improved tolerance towards these stresses. In the present paper, we discuss the success obtained so far; in raising brassica genotypes with improved salinity tolerance employing both plant breeding and/or genetic engineering tools.