Cross pathogenicity of Neofusicoccum australe and Neofusicoccum stellenboschiana on grapevine and selected fruit and ornamental trees

[EN] Neofusicoccum australe is one of the most important Botryosphaeriaceae pathogens occurring on fruit and vine crops. This fungus was recently taxonomically reassessed, identifying N. stellenboschiana as a separate species. Previous pathogenicity studies used N. stellenboschiana and N. australe isolates as N. australe, so assessment of the pathogenicity of these two species on grapevine and other hosts was required. A pathogenicity trial was conducted on detached shoots of grapevine, plum, apple, olive and Peruvian pepper tree. Shoots were individually inoculated with 11 N. australe and eight N. stellenboschiana isolates originally isolated from grapevine, plum, apple, olive, Peruvian pepper and fig. Both species formed lesions on all five hosts and were reisolated 5 weeks post-inoculation. In general, the largest lesions were formed on plum and smallest on Peruvian pepper. Isolate host origin did not influence ability to cause lesions on other hosts. Isolates of N. australe and N. stellenboschiana differed in virulence on the various hosts, ranging from those that caused the largest lesions, a group causing intermediate lesions, and another causing lesions similar to uninoculated controls. The study demonstrates that N. australe and N. stellenboschiana isolates originating from various fruit hosts can infect alternative hosts including grapevine and other major fruit crops.This research developed from a mobility sojourn funded by the Erasmus Mundus Joint Master Degrees Programme of the European Commission under the PLANT HEALTH Project. The authors also acknowledge financial support from ARC Infruitec-Nietvoorbij and the National Research Foundation of South Africa (NRF UID88771). Technical Assistance was provided by Carine Vermeulen, Danie Marais, Julia Marais, Muriel Knipe, Lydia Maart, Christopher Paulse, Bongiwe Sokwaliwa, Nadeen van Kervel, and Levocia Williams (Plant Protection Division, ARC Infruitec-Nietvoorbij).Mojeremane, K.; Lebenya, P.; Du Plessis, IL.; Van Der Rijst, M.; Mostert, L.; Armengol Fortí, J.; Halleen, F. (2020). Cross pathogenicity of Neofusicoccum australe and Neofusicoccum stellenboschiana on grapevine and selected fruit and ornamental trees. PHYTOPATHOLOGIA MEDITERRANEA. 59(3):581-593. https://doi.org/10.14601/Phyto-11609S58159359