First report of Botrytis cinerea in South African blueberry orchards

The South African blueberry industry has grown consistently over the past few years due to an increase in local and international demand. Like many other crops, blueberries are susceptible to grey mould caused by Botrytis cinerea, resulting in significant reductions in yield. In this study, Botrytis isolates were recovered from symptomatic blueberry fruit, flowers, leaves and undifferentiated buds, but were not found as endophytes in healthy tissues. Phylogenetic analysis of the concatenated glyceraldehyde-3-phosphate dehydrogenase (G3PDH), heat-shock protein 60 (HSP60) and DNA-dependent RNA polymerase subunit II (RPB2) genes identified 88 isolates as B. cinerea strains as well as a single B. pelargonii strain. The results presented in this study are the first to contribute towards the characterisation of B. cinerea populations in South African blueberry orchards.