ARS | Publication request: RESISTANCE TO BLIGHTING BY MONILINIA VACCINII-CORYMBOSI IN DIPLOID AND POLYPLOID VACCINIUM SPECIES

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 2, 1999
Publication Date: N/A

Interpretive Summary: Mummy berry, caused by the fungus Monilinia vaccinii-corymbosi, is one of the most important fungal diseases of blueberry in North America because of its widespread occurrence and potential for yield loss. The blighting stage of mummy berry causes foliage loss and can weaken plants and depress yield, and the fruit rot stage will infect fruit and cause direct loss of marketable product. Wild blueberry species were screened as possible sources of resistance which could be incorporated into the breeding process. The species Vaccinium boreale, V. corymbosum, V. darrowi, V. elliottii, V. myrtilloides, V. myrtillus, V. pallidum, V. tenellum, V. hirsutum, and V. corymbosum forma amoenum were evaluated for blight resistance under greenhouse conditions. V. boreale and V. myrtilloides were found to have particularly good resistance to mummy berry blight. Information on resistance levels in Vaccinium species will be of use to researchers and breeders developing new blueberry cultivars.

Technical Abstract: Resistance to blighting by Monilinia vaccinii-corymbosi (Reade) Honey was evaluated under greenhouse conditions in multiple populations of the diploid species Vaccinium boreale Hall & Aalders, V. corymbosum L., V. darrowi Camp, V. elliottii Chapm., V. myrtilloides Michx., V. myrtillus L., V. pallidum Ait., and V. tenellum Ait., as well as in accessions of the polyploid species 4x V. hirsutum Buckley and 6x V. corymbosum forma amoenum. Significant species differences were found in mean blighting levels averaged across two years, with values ranging from 3.2% for V. boreale to 50.5% for 2x V. corymbosum, compared to 27.3% for the resistant differences were found for 2x V. corymbosum, V. darrowi, V. elliottii, and V. pallidum. V. Vaccinium species may serve as excellent alternative or supplementary sources of resistance, if resistance can be transferred easily and horticultural type recovered.