Inheritance of resistance to Colletotrichum acutatum in strawberry (Fragaria x Ananassa)

The inheritance of resistance to anthracnose caused by Colletotrichum acutatum was investigated in six cultivars of varying resistance. Three cultivars chosen as female parents (Elsanta, Darestival and Rosanne) were crossed with three other cultivars chosen as male parents (Pajaro, Sequoia and Dover) to produce nine families. Progenies derived from selfing four parents were also obtained. Frequency distributions of disease responses within families were bimodal. Segregation ratios suggested that the resistance trait is dominant and monogenic. 'Dover' was homozygous and 'Rosanne' and 'Sequoia' were heterozygous for the resistant trait. In contrast, the three other cultivars were susceptible to C. acutatum, strain1267b. Preliminary results obtained in inoculation of seedlings with C. acutatum, strain 494a, suggested that the monogenic control of resistance to 1267b seems to be not effective against 494a.