An investigation was carried out during 2005-2007 in rice to screen salt tolerant genotypes, estimate the heritability parameters, association and genetic divergence for nine characters. The characters viz., plant height, total tillers, productive tillers, panicle weight and single plant yield registered high heritability and genetic advance indicating possibility of improvement through simple phenotypic selection. The correlation studies of yield-related traits revealed that panicle weight and spikelet fertility may be given due weightage while selection since they recorded highly significant positive association with single plant yield under saline alkaline condition.

Path analysis revealed that total tillers, spikelet fertility and panicle weight had direct and significant correlation with single plant yield and therefore selection based on the same can aid for genetic improvement. The 30 genotypes were grouped into nine and seven clusters based on Tocher's and Ward's method, respectively, with single plant yield contributing much to the total genetic divergence. It also indicated that Ward's method is superior to Tocher's method in resolving genotypes into different clusters. Based on Tocher's method of clustering, intercrossing between genotypes of cluster VII and cluster IX may throw an array of recombinants in the segregating generations for effective selection under saline alkaline condition.

In general, rice is life for Asians and in particular for Indians, as it provides 43% calorie requirement for more than 70% of the population (Rahman, 2006). Rice is planted in 40 mha with a production of 87.8 MT and the demand for rice is expected to be 100 MT during 2010 and 140 MT by 2025. This has to be achieved against the backdrop of diminishing natural resource bases like land, labor and water
(Mishra et al., 2003).

Among various abiotic stresses that limit rice productivity, salinity is a serious threat and it is further aggravated owing to the use of poor quality water for irrigation, improper drainage (Chinnusamy and Zhu, 2003). In India, out of 8.6 mha of salt affected soils, 2.19 mha are coastal saline where rice is the predominant crop which is subjected to 12% loss in the production system due to abiotic stresses
(Singh et al., 2003).

The strategies for mitigating saline alkaline problem in crop production include both development of management options and genetic improvement of salinity tolerance in the present day varieties (Shannon, 1997). Although, the use of some management options can ameliorate yield reduction under salinity stress, implementation is often limited because of cost and availability of good quality water resources. Therefore, the development of salt tolerant varieties would be a practical solution to address this problem.

Genetics & Evolution Journal, Tocher's Method, Salt Tolerance Index, Genetic Divergence, Genetic Diversity Analysis, Biometric Traits, Rice Productivity, Clustering Patterns, Genetic Diversity, Biometrical Research, Multivariate Analysis.