Comparison of Cold-Resistance in Some Iranian and European Grape Cultivars

One of the main problems in vineyards of Iran is sensitivity of grape cultivars to winter cold. Considering the rich genetic diversity of grape cultivars in Iran vineyards and severe cold winter in 2007, this situation was used as a natural treatment in order to identify cold tolerance and assess damages in 21 Iranian grape varieties and 8 European grape varieties in a factorial experiment, based on completely randomized blocks design with four replications and three plants per unit. In each plant, four branches (one year old) were selected and the number of healthy and damaged sprouts were counted. Then, statistical and cluster analysis was performed. Descriptive statistics (coefficient of variation of phenotypic traits) of the obtained data from assessment of grape cultivars was calculated. Using the correlation coefficient (Pearson r), bilateral relationship between traits was measured and the attributes which their selection could increase the efficiency were determined. The results indicated that grape cultivars were located in four groups of sensitive, semi-sensitive, semi-tolerant and completely tolerant. Ghermez Bidaneh, Fakhri, Siyah Gazvin, Khalili and Rish Baba cultivars showed the highest tolerance. Most of the European cultivars including Ruby Seedless, Superior, Fiesta, Black Seedless, Perlette, Flame Seedless, Tompson Seedless and Torkmanistan 4 were in semi-tolerant to susceptible groups. Tolerance threshold against winter cold was was 15 ±1 ◦C in normal varieties and 20 ±1 ◦C in tolerant cultivars. There was a significant phenotypic correlation between the studied traits.