关键词: 枣, 裂果, CaCl2, 细胞壁降解酶, 组织结构

Abstract:

Fruit cracking is seriously harmful to fruit production of Ziziphus jujuba in Northern China. The present study was undertaken to identify agronomic measures to reduce the dehiscent fruit rate of Ziziphus jujuba Mill.‘Huping Zao’，which is the most popular cultivar planted in Shanxi Province. The 0.01 g ? mL-1 CaCl2 solution was sprayed during the young fruit stage，fruit expanding stage，and fruit mature period respectively in the field. Then，the dehiscent fruit rate，fruit cell wall degrading enzymes，contents of cell wall compositions，and fruit microstructure were observed. The results showed the dehiscent fruit rate and activities of pectinase and cellulose were significantly decreased with the foliar application of calcium，while the contents of protopectin and cellulose were significantly improved in pericarp and pulp. The dehiscent fruit rate was positively correlated to the activities of pectinase and cellulose，but negatively correlated to the content of protopectin and cellulose. According to the microstructure，the cuticle of jujube fruit without crack was more intact and thicker than the control. Moreover，the fruit epidermal cells were more tightly arranged and smaller than the control，with less cavity in pulp cells. Our data suggested that foliar application of calcium could be applied as an important measure to prevent fruit cracking during both young fruit and fruit expanding stages.

Key words: Ziziphus jujuba, fruit cracking, CaCl2, cell wall degrading enzyme, microstructure