Inheritance of resistance to Colletotrichum acutatum in Fragaria x ananassa

Anthracnose, caused by Colletotrichum acutatum, is a major disease of the octoploid cultivated strawberry, Fragaria x ananassa. The inheritance of high and intermediate level plant resistances to C. acutatum, pathogenicity group 2, was investigated in an 8 x 8 factorial design. A single dominant gene (Rca2) controlled the high-level resistance, although minor genes may also contribute to resistance in cultivars such as Belrubi. The intermediate level of resistance was quantitative and controlled by minor genes. Analysis of 26 genotypes and cultivars from Fragaria spp. showed that the dominant gene was not rare in the germ plasm of E x ananassa and that anthracnose resistance was also present in other species of Fragaria. These findings have important implications for anthracnose resistance breeding.