赤霉素延缓‘丰水’梨落叶的生理机制  

The physiological mechanism of gibberellin effects on delaying leaf abscission in‘Hosui’pear

作　　者：郝紫微 吴潇[1] 戴雨沁 王鹏[1] 张绍铃[1] HAO Ziwei;WU Xiao;Dai Yuqin;WANG Peng;ZHANG Shaoling(Pear Engineering and Technology Research Center,College of Horticulture,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学园艺学院梨工程技术研究中心,江苏南京210095

出　　处：《南京农业大学学报》2021年第1期61-67,共7页Journal of Nanjing Agricultural University

基　　金：中央高校基本科研业务费专项资金(JCQY201903);国家现代农业(梨)产业技术体系(CARS-28)。

摘　　要：[目的]本文旨在从生理水平探究赤霉素(GA)对‘丰水’梨落叶的影响,为防控梨早期落叶提供依据与参考。[方法]以正常生长(对照组)和发生早期落叶的‘丰水’梨叶柄离区为材料,通过石蜡切片观察以及赤霉素、活性氧含量和抗氧化酶活性测定,分析其生理差异;通过喷施植物生长调节剂研究赤霉素对叶片保留率、抗氧化酶活性以及活性氧含量的影响。[结果]观察石蜡切片发现,早期落叶的‘丰水’梨叶柄离区组织发生明显的缢缩,离区的细胞比邻近细胞小且具有密集的细胞质。与对照组相比,早期落叶组的叶柄离区中,具有生理活性的GA 3和GA 4以及赤霉素合成关键中间产物GA 12含量均显著下降;超氧化物歧化酶、过氧化物酶和过氧化氢酶活性明显降低;超氧阴离子和过氧化氢含量显著增加。外源喷施赤霉素可提高叶柄离区抗氧化酶活性,降低活性氧含量,增加叶片保留率。[结论]适宜浓度的赤霉素处理可以提高叶柄离区的抗氧化酶活性,降低活性氧含量,延缓落叶的发生。[Objectives]The aim of this paper was to explore the physiological mechanism of gibberellin(GA)effects on delaying leaf abscission in‘Hosui’pear,which could provide reference for controlling the early leaf abscission in pear.[Methods]Taking the abscission zone from the petiole of‘Hosui’pear with normal growth(control group)and early leaf abscission as materials,through paraffin section observation,the contents of gibberellins and reactive oxygen species and the activities of antioxidant enzymes were determined and their physiological differences were analyzed.At the same time,the effects of gibberellin on leaf retention,antioxidant enzyme activity and active oxygen content were detected by spraying plant growth regulators.[Results]Through the observation of paraffin section,it was found that the petiole abscission zone of‘Hosui’pear with early leaf abscission had obvious constriction,and the cells in the abcsission zone were smaller than the adjacent cells and had dense cytoplasm.Compared with the control group,in the petiole abscission zone of the early leaf abscission group,the contents of GA 3 and GA 4 with physiological activity and GA 12,the key intermediate of gibberellin synthesis significantly decreased,the activities of superoxide dismutase,peroxidase and catalase significantly decreased,and the contents of superoxide anion and hydrogen peroxide significantly increased.Exogenous gibberellin spraying could increase the activity of antioxidant enzymes in the detached zone of petiole,reduce the content of reactive oxygen species and increase the retention rate of leaves.[Conclusions]The appropriate concentration of gibberellin can promote the activity of antioxidant enzymes,reduce the content of reactive oxygen species and delay the occurrence of leaf abscission.

关 键 词：梨 赤霉素 活性氧 抗氧化酶 叶片脱落 

分 类 号：S611.2[农业科学—园艺学]