Cultivar Differences in Response to Low Temperatures in Vitis vinifera Callus In Vitro

¹ Department of Horticulture, University of Alaska-Fairbanks, Agriculture and Forestry Experiment Station, Palmer, AK 99645
² Department of Horticulture and Landscape Architecture, Irrigated Agriculture Research and Extension Center, Prosser, WA 99350
³ Department of Horticulture, Michigan State University, East Lansing, MI 48824.

Callus cultures from Cabernet Sauvignon, Chardonnay, Grenache, and White Riesling (Vitis vinifera L.) were used to determine the effect of growth rate, acclimation temperature, and time of acclimation on cold hardiness in vitro. The growth rate of each cultivar on the prescribed media was established and used to determine equivalent starting times for treatment of each cultivar. Low temperature exotherms and freeze-regrowth analysis were evaluated to determine treatment effectiveness. Cabernet Sauvignon grew the most rapidly, with only a three-day lag phase before beginning exponential growth. Chardonnay, Grenache, and White Riesling were slower, with a seven- to 10-day lag phase and with fresh weights a third of that of Cabernet Sauvignon following 21 days in culture. Exotherm analyses were inadequate in determining cold hardiness in Vitis vinifera callus. The mean exotherm temperature for all cultivars was -11°C with a 10°C range between the first and the last exotherms in any given treatment. In freeze-regrowth and acclimation analyses, however, Chardonnay, Grenache, and White Riesling had mean survival temperatures of -10°C, -10C°, and -12°C, respectively, but Cabernet Sauvignon survived despite freezing to -20°C. Cabernet Sauvignon's rapid growth in culture may be responsible for its unusual survival at -20°C. Chardonnay, Grenache, and White Riesling exhibited slow growth and did not survive the acclimation treatments or freezing temperatures. Callus cultures were unable to acclimate to low temperatures, and chilling injury possibly resulted from exposure to the acclimation temperatures. Thus, unlike intact plants where freezing tolerance is often associated with lack of growth or dormancy, here actively growing cells survived freezing.

Key words: acclimation, cold hardiness, temperature, Vitis vinifera

Submitted on June 18, 1990