枇杷果实发育过程中果肉质地与胞壁酶活性的变化

以果肉质地差异较大的白肉枇杷（Eriobotrya japonica Lindl.）“白梨”和黄肉枇杷“解放钟”为试材， 探讨果实发育过程中胞壁酶活性变化与果肉质地形成的关系。 结果表明， 2个品种枇杷果实发育过程中多聚半乳糖醛酸酶（PG， EC 3.1.1.15）、 果胶酯酶（PE， EC 3.1.1.11）与纤维素酶（Cx， EC 3.2.1.4）活性总体呈上升趋势， 这3种酶活性在果实发育后期（即花后100~115 d）极显著高于前期并出现峰值。“白梨”枇杷PE，PG和Cx酶活性高于“解放钟”， 果实发育前期， 2个品种枇杷PE， PG和Cx酶活性差异较小； 果实发育后期，“白梨”PE， PG和Cx酶活性显著或极显著高于“解放钟”。Cx， PG和PE与枇杷果肉质地形成密切相关， 而β-半乳糖苷酶（EC 3.2.1.23）、 α-葡萄糖苷酶（EC 3.2.1.20）、 α-半乳糖苷酶（EC 3.2.1.22）、 α-甘露糖苷酶（EC 3.2.1.24）等4种糖苷酶对“白梨”枇杷果实发育后期果肉软化起到一定的作用。

The Change of Cell Wall Enzymes and Fruit Texture during the Development and Maturation of Eriobotrya japonica

’Baili’and’Jiefangzhong’were used as the material to study the relationship between the change of cell wall enzymes and fruit texture of loquat(Eriobotrya japonica).The results showed that polygalacturonase(PG,EC 3.1.1.15),pectinesterase(PE,EC 3.1.1.11)and Cellulase(Cx,EC 3.2.1.4) activities of the two cultivars were increasing in general during fruit development.The activities of the above three enzymes during the late fruit developing stages were significantly higher than those in the early fruit growth stages,and peak appeared during the late fruit developing stages.PE,PG and Cx enzymes activities of’Baili’ were higher than those of ’Jiefangzhong’.During early fruit growth stages there were few differences in PE,PG and Cx activities between ’Baili’and ’Jiefangzhong’.During the late fruit developing stages,PE,PG and Cx enzymes activities of ’Baili’were significantly higher than those of ’Jiefangzhong’.The activities of PE,PG and Cx were closely related to loquat fruit texture,and several glycosidase enzymes including β-galactosidase(β-Gal,EC 3.2.1.23),α-glucosidase(α-Glu,EC 3.2.1.20),α-galactosidase(α-Gal,EC 3.2.1.22),α-mannosidase(α-Man,EC 3.2.1.24) of ’Baili’ loquat played some role in the pulp softening during the late fruit developing stages.