Inheritance of partial resistance to race 2 of Albugo candida in canola-quality mustard (Brassica juncea) and its role in resistance breeding

The inheritance of partial resistance to race 2 of Albugo candida was studi ed in a canola-quality line of Brassica juncea. This partially resistant li ne was crossed with the susceptible B. juncea cultivar Commercial Brown. F- 1, F-1(reciprocal), F-2, BC and doubled haploid generations from the cross were inoculated with a zoospore suspension of race 2 to study segregation o f partial resistance. The partially resistant phenotype appeared to be cont rolled by a single dominant gene that has variable expression. This partial resistance can have implications in breeding for disease resistance agains t white rust, as adult plants did not develop hypertrophic growth or staghe ads under greenhouse and field conditions.