荔枝裂果与果实生长及水分吸收动力学的关系

荔枝采前裂果发生于假种皮速长期,台风雨是诱发裂果的典型气候现象,在此期间,日裂果率(DCR)果径日净增值(DNG)和蒸汽压亏(VPD)三者之间呈极显著相关。VPD猛跌抑制叶蒸腾使水分大量涌入果实。喷脱落酸以抑蒸腾也产生相同结果。环剥增多果内可溶性图形物,降低渗透势,也诱发裂果。台风雨诱发果实非常规的呼吸峰。浸果实验证明吸水与呼吸相关。认为荔枝果实吸水包含被动吸水,即渗透势降低和叶蒸腾减弱引起的水流转向,也包含由呼吸提供能量的主动吸水过程。

LITCHI FRUIT CRACKING IN RELATION TO FRUIT GROWTH AND WATER-UPTAKE KINETICS

Litchi fruit cracking ocurred mainly in the pre-harvest period of rapid aril growth.Significant correla-tions were found among the DCR (daily fruit-Cracking rate).DNG (daily net growth in fruit diameter) and VPD (atmospheric vapour pressure deficits).It was especially typical during the typhoon rain spell,when an unusual burs: of growth of the fruits was demonstrated concurrently with the drastic drop of VPD.Litchi fruit crac king is assumed to be associated with an actilve uptake of water,which is motivated by the enhanced respiration of the fruits,another unconventional demonstration during the typhoon rain spell,aside from the passsive influx of water into the fruits caused by the diversion of water stream due to depressed leaf transpiration and also by the drop of osmotic potential in the aril sap.