RELATIONSHIP BETWEEN NONSTRUCTURAL CARBOH YDRATE CONCENTRATION AND SNOW TOLERANCE OF PEA (PISUM-SATIVUM L)

Pea (Pisum sativum L.) seedlings planted in Hokuriku area in the fall are often covered by snow. Some cultivars withstand the snow, whereas others do not. This study sought the relationship of snow tolerance wi th seeding time and nonstructural carbohydrate (NSC) concentration amo ng cultivars to clarify the tolerance mechanism. 1. Varietal differenc es in snow tolerance in 33 cultivars revealed that tolerant cultivars were shorter in stature and had lighter foliage and numerous branches before snow cover than had the snow-vulnerable ones. If NSC concentrat ion in the cotyledons was two to tree times higher than that in the fo liage, it contributed significantly to snow tolerance. 2. With delayed seeding time in the fall, high water soluble carbohydrate (WSC) conce ntration in the foliage accompanied by a proportional decrease in plan t dry weight before snow cover promoted snow tolerance. The cultivars and late seeding plants possessing high NSC in the cotyledons showed h igh snow tolerance, indicating the importance of NSC protecting the ov erwintering pea seedling under snow.