The wild members of family brassicaceae are treasurers for invaluable genes of resistance. Sinapis alba a wild member of this family was reported to carry resistance to various biotic and abiotic stresses. Therefore, we evaluated here two symmetric somatic hybrids (allohexaploids = AABBSS) of B. juncea (AABB) and S. alba (SS) developed by protoplast fusion for biotic and abiotic stresses. These two allohexaploids of brassicas referred hereafter as H1 and H2. The hybrids were evaluated against two major diseases of rapeseed-mustard i.e. Alternaria blight and Sclerotinia stem rot including tolerance to high temperature. The results of the study showed that H2 somatic hybrid showed very high degree of resistance against Alternaria blight. While, H1 somatic hybrid possessed complete resistance to Sclerotinia stem rot along with Alternaria blight. However, both the hybrids expressed very good tolerance to high temperature at the time of seed setting. These hybrids were screened for disease resistance against the Alternaria blight and Sclerotinia stem rot in four different environments during seven successive seasons. These two allohexaploids also remained stable and completely fertile after the eight subsequent generations. Therefore, these somatic hybrids are novel genetic stocks to develop climate resilient varieties.

Keyword: Sinapis alba; B. juncea ; Alternaria blight; Climate resilient varieties; Sclerotinia stem rot;