Histochemical and Microscopic Studies Predict that Grapevine Genotype "Ju mei gui" is Highly Resistant against .

The necrotrophic fungus causes devastating pre- and post-harvest yield losses in grapevine ( L.). Although has been well-studied in different plant species, there is limited information related to the resistance and susceptibility mechanisms of genotypes against infection. In the present study, leaves and berries of twenty four grape genotypes were evaluated against infection. According to the results, one genotype (Ju mei gui) was highly resistant (HR), one genotype (Kyoho) was resistant (R), eight genotypes were susceptible (S), and fourteen genotypes were highly susceptible (HS) against infection of in leaves. Whereas in the case of infection in grape berry, three genotypes were found to be highly resistant, three resistant, eleven genotypes susceptible, and seven were highly susceptible. To further explore the mechanism of disease resistance in grapevine, we evaluated "Ju mei gui" and "Summer black" in terms of progression, reactive oxygen species reactions, jasmonic acid contents, and the activities of antioxidant enzymes in leaf and fruit. We surmise that the resistance of "Ju mei gui" is due to seized fungal growth, minor reactive oxygen species (ROS) production, elevated antioxidant enzyme activity, and more jasmonic acid (JA) contents. This study provides insights into the resistance and susceptibility mechanism of genotypes against . This will help for the selection of appropriate germplasm to explore the molecular basis of disease resistance mechanisms in grapevine.