Graduate Research Associate The Ohio State University Columbus, Ohio
Body of Abstract:
Frequent late-spring frosts affect cultivated grapevine (Vitis vinifera L.) yield by damaging the emerging shoots, resulting in huge economic losses. For example, the Polar Vortex of 2014 caused an economic loss worth $4 million to the grapevine growers in Ohio. One of the long-term solutions to avoid frost damage is the selection of cultivars appropriate for a specific growing region based on the chilling requirement, rate of budburst, and frost tolerance. Wild grapevine species, such as Vitis labrusca, are cold-tolerant and are a great source of variation related to chilling requirement, however, compared to other wild species, V. labrusca is also thought to be a fast-bursting species, i.e., budburst is achieved faster under conducible growing conditions after the vines have met their chilling requirement. A three-year study was conducted using eight V. labrusca accessions to determine the relationship between chilling hours and days to budburst. A multiple linear regression showed that despite being fast-bursting, there was significant interspecific variation related to the rate of budburst among V. labrusca accessions. Further, we investigated whether newly emerging young shoots of cold-hardy and fast-bursting Vitis labrusca can tolerate frost conditions. Single-bud cuttings of cold-tolerant V. labrusca acc. ‘GREM-4’ and cold-sensitive V. vinifera cv. ‘Cabernet Sauvignon’ were forced to budburst and then were provided artificial frost conditions (-2℃ or below). On assessing the frost injury after 24 hours, we observed significantly lower frost injury among V. labrusca acc. ‘GREM-4’ cuttings as compared to V. vinifera cv. ‘Cabernet Sauvignon’. Therefore, although being a fast-bursting species, the young shoots of V. labrusca acc. GREM-4 showed resilience to simulated frost. Categorization of grapevine accessions based on the chilling requirement, rate of budburst, and frost tolerance can assist grapevine breeders in choosing appropriate accessions for the development of frost-tolerant cultivars.