扁桃生理落果期不同组织蔗糖代谢动态特征及与落果的关系

The sucrose metabolism dynamics in different tissues of almond during the physiological fruit drop and its relations with fruit drop

以新疆主栽扁桃品种‘纸皮’扁桃为试材,分析了生理脱落期幼果(包括包括正常果和即将脱落果)、果柄(包括正常果果柄和即将脱落果果柄)、结果母枝韧皮部、当年生新枝、叶片等组织间蔗糖、葡萄糖、果糖浓度和蔗糖代谢关键酶活性,同时研究去除新梢对扁桃生理落果率和坐果率的影响。结果表明,扁桃幼果生理脱落期不同组织的糖分含量和蔗糖代谢关键酶的活性呈规律性变化,且与扁桃的落果动态规律相对应;扁桃幼果生理脱落期的蔗糖代谢以分解为主,蔗糖分解方向的酶起主要作用;新梢与幼果间竞争光合产物导致幼果葡萄糖供应不足引起了落果,蔗糖酸性转化酶和分解方向蔗糖合成酶是调控扁桃幼果脱落与否的关键酶。

To further reveal the physiological mechanism of young fruit drop of almond(Amygdalus communis),the dynamic features of sucrose metabolism in different tissues during the physiological fruit drop and its relations with fruit drop were studied.In this study,‘Zhipi’almond which is the main planting cultivars in Xinjiang,was selected as target material,the concentration of sucrose,glucose,fructose and key enzyme activites in sucrose metabolism[acid invertase(AI),neutral invertase(NI),sucrose synthase(SS),sucrose phosphate synthase(SPS)],in young fruit(normal fruit and fruit about to drop),fruit stalk(normal fruit stalk and fruit stalk about to drop),phloem of fruiting branch,one-year shoots,and leaves of almond during the physiological fruit drop were analyzed.At the same time,the effects of removing new shoots on the physiological fruit drop and setting rate were observed at field condition.The results showed that the changing paten of sugar components and enzyme activities in sucrose metabolism in different tissues of almond during the physiological fruit drop were corresponding with the dynamic laws of fruit dropping.Sucrose metabolism in almond young fruits during physiological fruit drop was dominated by decomposition and the enzymes in the direction of sucrose decomposition played a major role.Competition of photosynthates between shoots and young fruits led to insufficient glucose supply in young fruits and caused the fruit drop.Sucrose acid invertase(AI)and sucrose synthase(SS)at decomposition direction were the key enzymes regulating the dropping of almond young fruits.