INHERITANCE OF RESISTANCE IN BRASSICA-NAPUS TO AN ETHIOPIAN ISOLATE OF ALBUGO-CANDIDA FROM BRASSICA CARINATA

The inheritance of resistance to an isolate of Albugo candida collected from Brassica carinata in Ethiopia was investigated using two Brassica napus lines. All 33 F1 plants derived from two crosses between the resistant line 2282-9 and the susceptible line DHF86-36 showed a resistant reaction. The segregation ratio of 3 resistant: 1 susceptible in the F2 generation suggests that resistance of 2282-9 to the B. carinata isolate is conditioned by a single dominant resistance gene. This was confirmed when progenies derived from the backcross between F1 plants and the susceptible parent segregated in a 1:1 ratio for resistance and susceptibility. The results are discussed in the context of the relationships between genotypes of Brassica species and races and isolates of A. candida.