Resistance evaluation of Chinese wild Vitis genotypes against Botrytis cinerea and different responses of resistant and susceptible hosts to the infection

摘要

The necrotrophic fungus Botrytis cinerea is a major threat to grapevine cultivation worldwide. A screen of 41 Vitis genotypes for leaf resistance to B. cinerea suggested species independent variation and revealed 18 resistant Chinese wild Vitis genotypes, while most investigated V. vinifera , or its hybrids, were susceptible. A particularly resistant Chinese wild Vitis , “Pingli-5” ( V. sp. [Qinling grape]) and a very susceptible V. vinifera cultivar, “Red Globe” were selected for further study. Microscopic analysis demonstrated that B. cinerea growth was limited during early infection on “Pingli-5” before 24 h post-inoculation (hpi) but not on Red Globe. It was found that reactive oxygen species (ROS) and antioxidative system were associated with fungal growth. O 2 - accumulated similarly in B. cinerea 4 hpi on both Vitis genotypes. Lower levels of O 2 - (not H_(2)O_(2)) were detected 4 hpi and ROS (H_(2)O_(2)and O 2 - ) accumulation from 8 hpi onwards was also lower in “Pingli-5” leaves than in “Red Globe” leaves. B. cinerea triggered sustained ROS production in “Red Globe” but not in “Pingli-5” with subsequent infection progresses. Red Globe displayed little change in antioxidative activities in response to B. cinerea infection, instead, antioxidative activities were highly and timely elevated in resistant “Pingli-5” which correlated with its minimal ROS increases and its high resistance. These findings not only enhance our understanding of the resistance of Chinese wild Vitis species to B. cinerea , but also lay the foundation for breeding B. cinerea resistant grapes in the future.