Field evaluation of Indian and exotic oilseed Brassica napus and B. juncea germplasm against Sclerotinia stem rot.

Sclerotinia stem rot, incited by Sclerotinia sclerotiorum (Lib) De Bary, continues to be a serious disease across oilseed Brassica growing areas in India, China and Australia. As it is not possible to manage this disease using chemical or cultural means, sources of host resistance need to be identified against this pathogen. Germplasm, comprising genotypes of Brassica napus (L.) and Brassica juncea (L.Czern & Coss.) from Australia, China and India were screened under field conditions in north India. Using a stem inoculation test, resistance sources were identified among genotypes from Australia including the cultivars ‘Ag Spectrum’ and ‘Ag Outback’, accessions ‘RR002’ and ‘JM 018’ and from China including accessions ‘RH 13’, ‘Ringot’, ‘Brassica juncea 1’ and ‘Brassica juncea 2’. Using a soil inoculation test, sources of resistance in B. juncea genotypes from India were also identified including ‘Sanjucta asesh’, ‘PCR 7’, ‘RH 819’ and ‘Vardan’. These sources of resistance will be useful towards developing new cultivars of B. napus and B. juncea with improved host resistance to S. sclerotiorum.