Salinity is a barrier of crop production while salinity affected areas are expanding in Bangladesh. To increase oilseed production in saline soils, a useful tactic could be developing salinity tolerant mustard varieties. This study screened advanced breeding lines of rapeseed-mustard along with a check variety for salinity tolerance. An experiment was conducted for morphological and genetic assessments at the field laboratory following a split plot design (RCBD) with six genotypes (BD-6950, BD-7104, BD-10115, JUN-536, BJDH-12 and BARI Sarisha-14 as a check) and five salinity treatments (0, 6, 8, 10 and 12 dSm-1). A total of 16 morphological characters were recorded. Significant variations were accounted among the genotypes and treatments for all characters. A significant and positive correlation was found among seed yield plant-1 and 1000-seed weight, number of seeds siliquae-1, length of siliqua, length of primary branches. All morphological characters except number of secondary branches and length of siliqua showed high heritability, from 62% to 98%, which indicated that these characters can be selected for further improvement. Genetic analyses revealed that high heritability with genetic advance in percentage of mean was observed for number of seeds siliquae-1, number of siliqua in primary axis, number of siliqua in secondary axis, total siliqua plant-1 and seed yield plant-1 could be suitable indicators for salinity tolerance. Principal component analysis revealed that days to first flowering and days to maturity were contrasting with other variables for salinity stress tolerance in the genotypes BD-7104 and BD-10115 under 8 and 10 dSm-1 salinity levels. Based on the whole analyses, the genotypes BD-7104 followed by BD-10115 were the most suitable salt tolerant genotypes which can greatly contribute to oilseed production in saline prone areas. Further research would be more useful for QTL mapping of salt tolerant traits and developing of new, improved and climate smart salt tolerant variety of oilseed Brassica.
Key words: Salinity tolerance, genetic analysis, principal component analysis, rapeseed-mustard