套袋对翠冠果实外果皮褐斑形成结构及生理影响

Effects of Bagging on Rust Formation and Physiology of Fruit Exocarp in Pear Variety “Cuiguan”

套袋技术是提高梨果实外观品质的有效手段,为了探明梨果实发育期到成熟期套袋对锈斑发生的抑制机理,以半锈砂梨翠冠为试材,套袋果实为处理,不套袋果实为对照,观测果实发育期到成熟期锈斑的发生进程、测定不同时期果实外果皮果锈指数、木质素含量及相关合成代谢酶PAL酶、4CL酶、C4H酶、CAD酶、POD酶的活性。结果表明:套袋后梨果实外果皮锈斑发生进程明显减缓且程度轻,套袋果实锈斑发生在盛花后50 d,比不套袋(对照)晚20 d;果实迅速膨大期(盛花后70 d),套袋果实与不套袋(对照)果锈指数差异最大,套袋果锈指数减少41.67%;不套袋的翠冠褐斑严重,外果皮中木质素单体含量以及木质素合成代谢关键酶(PAL酶、4CL酶、CAD酶、C4H酶)活性普遍高于套袋翠冠果实外果皮。

Bagging technique is an effective way to improve the appearance quality of pear fruits. In order to find out the inhibiting mechanism of bagging on the occurrence of rusts in fruits of semi-russet sand pear variety ＂Cuiguan＂,we observed the occurrence progress of rusts in pear fruits from fruit development to maturity,and measured the rust index,lignin content and activities of phenylalanine ammonia-lyase（ PAL）,4-hydroxycinnamate Co-A ligase（ 4 CL）,cinnamate-4-hydroxylase（ C4 H）,cinnamyl alcohol dehydrogenase（ CAD） and peroxidase（ POD） in the exocarp of pear fruits at various developmental stages. The results showed that： after the bagging treatment,the occurrence progress of rusts in the exocarp of pear fruits was obviously slowed down,and the occurrence degree of rusts was reduced. The rusts in bagged fruits occurred on the 50 th day after flourishing blooming,20 days later than those in non-bagged fruits. At fruit rapid expansion stage（ on the 70 th day after flourishing blooming）,there was a biggest difference in rust index between bagged fruits and non-bagged fruits,and the rust index of bagged fruits was reduced by 41.67%. The rust occurrence was serious in the exocarp of non-bagged fruits,and the lignin content and the activities of PAL,4 CL,CAD and POD in the exocarp of non-bagged fruits were generally higher than those in bagged fruits.