Screening and breeding for genetic resistance to anthracnose in mango

Postharvest diseases remain a significant constraint to the transport, storage and marketing of mangoes. The two main ones are anthracnose and stem end rot. Anthracnose caused by Colletotrichum gloeosporioides is the more wide-spread of the two. Varieties within Mangifera indica are known to vary in their level of reactions to anthracnose; however, the best tolerance in current commercial cultivars is not sufficient to eliminate the need for pre- and postharvest fungicides treatments. A screening program was initiated in mango accessions in the Australian National Mango Genebank to look for any significant resistance to C. gloeosporioides in fruit as they ripened. Screening was conducted by rating reactions to natural infection of anthracnose and reactions to artificially inoculating fruit with virulent isolates of C. gloeosporioides. A range of reactions to the pathogen were identified, with strong resistance found in one accession of the species M. laurina. This accession was used as the pollen parent in a controlled crossing program with a M. indica hybrid from the Australian Mango Breeding Program (AMBP). Sixty successful hybrids between the species have been generated. The hybrid population will be screened for resistance to anthracnose and used for gene discovery investigations to identify markers for anthracnose resistance.