关键词: 枣, 果实, 水分, 维管束, 质外体运输

Abstract: The objective of our study was to investigate the mechanism of fruit cracking caused by
water uptake in Zizyphus jujuba Mill. The easily crack variety of jujube‘Huping’was used as material.
Apoplastic dye solution was used as the tracer to monitor the water uptake and transport in detached fruits
and branches with leaves and fruits. The results showed that water uptake by detached jujube fruits
occurred through pedicel end and fruit surface. Water entered into fruits through pedicel xylem vascular，
and accumulated in cavity under stalk. The vascular under epidermis and around fruit stone were stuffed
by dye solution，and the speed of dye solution transport in the vascular bundles were high during fruit
swell period，however，the distribution of stuffed dye in vascular bundles decreased and the speed of dye
solution transport decreased during coloring period. This is because of breakoff of vascular bundles and
non-functional xylem. While the ability of water uptake through fruit surface was enhanced during
coloring period，responding to enlarged and loosen epidermal cells. It suggested that the efficiency of
water transport in vascular of jujube fruits was decreased from fruit coloring stage，this led to water uptake
through the fruit surface become potential importance to fruit crack during raining.

Key words: jujube, fruit, water, vascular bundle, apoplastic transport