In vitro evaluation system for varietal resistance against ripe rot caused by Colletotrichum acutatum in grapevines

Ripe rot caused by Colletotrichum spp. occurs severely in grapevines grown in warm and humid climatic regions such as Korea. Research was initiated to develop an efficient screening system for grapevine resistance against ripe rot through the inoculation of C. acutatum spore suspensions grown in potato dextrose agar. Resistant grapevine cultivars against ripe rot were easily distinguished from susceptible ones through lesion scorings of the detached leaves and immature fruits inoculated with mycelial blocks or spore suspension of C. acutatum at 25 °C Resistant grape cultivars identified through pathogen inoculation include: ‘Zabalkanski’, ‘Benianyo’, and ‘Beniyamabico’. The evaluation of grapevines varietal resistance against ripe rot revealed some specificity in the culture filtrates for the pathogens. Hence, the application of culture filtrates treatment of C. acutatum can be an alternative approach for screening the ripe rot varietal resistance in grapevines.