螺旋环剥对‘糯米糍’荔枝坐果与碳水化合物及激素的影响

研究结果表明，幼‘糯米滋’荔枝主要螺旋环剥能减少碳水化合物向根系转运，从而增加叶片和果实中的碳水化合物含量，增多果实中赤霉素类物质和降低脱落酸类物质含量。坐果率的提高与赤霉素／脱落酸的比值较高关系密切。

Carbohydrate and Endohormone Status in Relation to Fruit Set as Influenced by Trunk Spiral Girdling of Young Litchi Trees

Trunk spiral girdling done in early December improved fruitset of young litchi trees of cultivarNuomizi,which tend to nonbearing.It was suggested that improved fruitset was associated with the additional supplies of carbohydrates from leaves to fruits as a result of reduced flow of carbohydrate to the roots.Improved fruitset was seemingly also linked with the enhanced level of GA and GA/ABA ratio caused by trunk spiral girdling.A couple of peaks of auxins and cytokinins in fruits were present during the period of physiological fruitset and fruit growth of nontreated trees,but were absent with girdled trees apparently due to inhibited shoot and growth.Yet the role of auxins and cytokinins in fruitset in the present case was quite unclear,it has been well believed that the lack of auxins are responsible for the distinctive preharvest drop in the abortedseeded cultivars likeNuomizi.