关键词: 猕猴桃, 耐贮性, 果胶酶, 超微结构, 组织结构

Abstract: Two kiwifruit cultivars‘Xuxiang’（shorter storage life）and‘Hayward’（long storage life），were used to study the changes in physiological and tissue structure during storage at 0 ℃，so as to explore the internal mechanism of kiwifruit storage ability，and provide information for further selection of excellent cultivars with good storability. The results showed that the firmness of both kiwifruit cultivars decreased continuously，and the time of firmness dropping to 10 N during storage was 150 days and 95 days for‘Hayward’and‘Xuxiang’，respectively. The peaks of respiratory rate and ethylene release rate on‘Xuxiang’appeared 20 days and 10 days earlier than that of‘Hayward’，and the peak values were 16% and 250% higher than that of‘Hayward’，respectively. The higher weight loss rate was observed on‘Xuxiang’as compared with‘Hayward’. From the maturity stage to the following storage period，the contents of starch，protopectin and cellulose of‘Hayward’were higher than that of‘Xuxiang’，while the enzyme peak activities of amylase（AM），pectin（PG，PE，β-Gal）and cellulase（Cx）were lower than that of‘Xuxiang’. In terms of fruit tissue structure，the epidermal hair of‘Hayward’was significantly shorter than that of‘Xuxiang’. Moreover，the thickness of cuticle and the number of epidermal cells were larger than that of‘Xuxiang’. The degree of deformation in pulp cells of‘Hayward’during storage was less than that of‘Xuxiang’. Fruit ultrastructure showed that the cell wall of‘Hayward’was thicker than that of‘Xuxiang’；in addition，the division speed of cell wall and intercellular layer in‘Hayward’was slower as compared with‘Xuxiang’. Meanwhile，the mitochondria showed relative structural integrity in‘Hayward’. In conclusion，kiwifruit with good storage ability has thick cuticle and epidermal cells，low weight loss rate，slow respiration rate and ethylene release rate，and low cell wall enzyme activity.

Key words: kiwifruit, storability, pectinase, ultrastructure, tissue structure