Physiological, biochemical and genetic responses of Caucasian tea ( (L.) Kuntze) genotypes under cold and frost stress.

Background: Cold and frost are two serious factors limiting the yield of many crops worldwide, including the tea plant (L.) Kuntze). The acclimatization of tea plant from tropical to temperate climate regions resulted in unique germplasm in the North-Western Caucasus with extremely frost-tolerant genotypes.