Abstract: In this study，the cracking-resistant‘Yuanling’and the susceptible‘Jun’jujube were used
as materials. The fruit growth curve，fruit shape index and the abortive rate of seed were measured.
Endogenous hormones content in pericarp，pulp，seed and the activities of enzymes related to cell-wall
metabolism in pericarp and mesocarp were determined. The result showed that the fruit shape index and
seed abortive rate of‘Yuanling’cultivar was significantly higher than‘Jun’cultivar. The GA3 content in
pericarp and IAA content in pulp of‘Jun’was evidently higher than‘Yuanling’during the late
developmental stages of fruit，however，the content of ABA in pulp and seed of‘Yuanling’was significantly higher than‘Jun’cultivar. The ratio of（GA3 + IAA + ZT）/ABA in pulp and seed of‘Jun’
was higher than‘Yuanling’cultivar during the whole developmental stages of fruit. Compared to
‘Yuanling’cultivar，‘Jun’has a higher activities of pectinase and cellulase in pericarp and activities of
POD and PPO in pulp during the late developmental stages. The result showed that the accumulation of
IAA in the pulp of fruit during the late developmental stage was higher in susceptible cultivar，but the
content of ABA in the pulp and seed of fruit was significantly higher in cracking-resistant cultivar，the
variety which has the high ratio of（GA3 + IAA + ZT）/ABA were more susceptible to cracking. The
pectinase and cellulase activity in the pericarp of fruit during the late developmental stage affect the
occurrence of the cracking，the activity of POD and PPO in the susceptible cultivar was higher than
cracking-resistant cultivar.

Key words: jujube, fruit cracking, endogenous hormones, enzymes activities