Studies On Postharvest Berry Drop Principle Of The Seedless Table Grape

The seedless table grape was used as material by way of plant physiology,biochemistry and plant issue anatomy to study the effect of different growth regulator on hydrolytic Enzyme activity in the abscission zone, adscission zone cell,the release of respiratory and ethylene of berry and stalk and the level of endogenous hormone in berry and stalk.It had discussed the way of postharvest berry drop, in order to providing theoretical support for reducing abscission of the seedless grape. The activity of cellulase, polygalacturonase and peroxydase in abscission zone increased during storage period,while pectinesterase increased slowly in prophase and drop in later period, Under normal temperature, the grape was treat with some plant growth regulator, the correlated Enzyme activity changed remarkably after 48 hours. The activity of cellulase ,polygalacturonase and peroxydase was promoted by exogenous ABA and ethylene but was inhibited by GA3and IAA . IAA and GA3content in different part decreased but ABA increased during storage period, the hormone content in stalk and abscission zone changed markedly while change wasn't obvious in berry ,Under the normal temperature, the grape was treated by plant growth regulator , effect on stalk and abscission zone was much more marked than berry. During we study effects of plant growth regulator on the release of respiratory and ethylene of grape berry and stalk , we found the release of respiratory and ethylene of berry change littlely, the rates of respiration ethylene of stalk was promoted by exogenous ABA and ethylene,but was inhibited slightly by exgenous IAA and GA3. Abscission of seedless table grape was related with the abscission layer cell formation. the result showed the cell which lie in the joint of the berry and stalk formed the abscission layer slowly .In prophase, the central joint cell was not formed abscission layer, but in the side of stalk the abscission layer cell began to form . with the prolong of storage period , the abscission layer cell formed in phloem and pith, but there wasn't the abscission layer cell in the central vessle. The growth regulator retarded abscission layer cell formation ,but the abscission cell formation was not consistent with berry drop .