A comprehensive assessment method for cold resistance of grape vines

To establish a comprehensive assessment method for cold resistance of grapes,branches from seven grape cultivars were exposed to different temperatures(10,-5,-15,-25,-35,-45℃).After exposure,cold resistance-related indices,including soluble sugar content,soluble protein content,malondialdehyde(MDA)content,free proline content,water content and relative electric conductivity,were measured.The most efficient temperature range for determining cold resistance-related indexes was decided by assessing changes indices after low temperature exposure.Semi lethal temperature(LT50)was calculated using relative electric conductivity.The LT50 was used to assess cold resistance indices using correlation analysis.The cold resistance indices were then subjected to principal component analysis.A comprehensive method for assessing cold resistance in grapes was established using a membership function method.The cold resistance of cultivars was found to vary:ShuangyouZuoyouhongBeibinghongBeda5BB5CPinot noir.Our results indicated that soluble sugar content,soluble protein content,free proline content,MDA content and relative electric conductivity were significantly correlated with cold resistance in these grape cultivars.Principal component analysis combined with membership function analysis was useful for evaluating cold resistance in grapes.