Relationship between nonstructural carbohydrate concentration and snow tolerance of broad bean (Vicia faba L.)

摘要

The relationship between non-structural carbohydrate (NSC) concentration and snow tolerance of broad bean was investigated. The growth and NSC of plants in early winter were altered by sowing on different dates. Three varieties (hardy, intermediateand susceptible) were used to study the relationship between NSC and snow tolerance, and changes in NSC and injury caused by snow were examined. Although intermediate and susceptible varieties sown in early autumn almost died after 54 days under snow, ahardy variety sown in early autumn showed high wintering ability. Plants sown in late autumn showed high wintering ability and a high NSC concentration (>15%) NSC in cotyledons. NSC in cotyledons of the hardy variety was not higher than that in the othertwo varieties. However, NSC in foliage, excluding cotyledons, and roots of the hardy variety sown earlier was higher than those of the other varieties. The results suggest that the hardy variety accumulated high NSC, and that the intermediate and susceptible varieties showed high wintering ability when NSC in cotyledon was utilized over winter. Under snow, NSC in leaves and stems decreased rapidly. The snow injury of intermediate and susceptible varieties increased rapidly after 36 days under snow, accompanying the decrease of NSC below 1% in leaves and 2% in stems. In contrast, the hardy variety showed no serious injury because of high NSC. It is concluded that a high value of NSC in plants was important to maintain a tolerance of snow injury.