Effects of Bemisia tabaci damage on the protective enzyme activity and the secondary metabolite content of leaves indifferent pepper varieties
Author of the article:KONG Hai-Long1** Lü Min2 WU Lin1 ZHU Shu-De1***
Author's Workplace：1. College of Plant Protection and Horticulture, Yangzhou University, Yangzhou 225009, China;2. Agricultural Institute of Lixiahe Area, Yangzhou, 225009, China
Key Words：pepper varieties, Q biotype Bemisia tabaci, adult feeding, SOD, POD, secondary metabolites
Abstract：[Objectives] To investigate the mechanism underlying the resistance of pepper varieties to whitefly. [Methods] Protective enzyme activity and the secondary metabolite content were studied in the leaves of different varieties pepper plant damaged by the Q biotype whitefly. [Results] The results show that there was a significant difference in the activity of SOD and POD and the total phenolic content in the leaves of different pepper varieties fed on by Q the biotype whitefly. SOD activity increased after whitefly damage in all six varieties peppers. Except for the susceptible Gangshanghong pepper variety, SOD activity in the other five varieties was significantly different from the control, and POD activity of resistant varieties ( Sujiao 5 and Xinyan 988 pepper king ) and moderately resistant varieties (Xiaoxin 9 and Xiangxin 3) increased significantly relative to the control. In contrast, POD activity of the susceptible varietiesGangshanghongandDayuniujiaowang) were significantly less than that of the control. The difference in SOD and POD activity in resistant varieties between damaged and undamaged pepper leaves was highest, followed by the medium resistant varieties, whereas the least difference was observed in the susceptible varieties. Total leaf phenolic and total flavonoid content in most pepper varieties significantly increased after whitefly infestation, and the total phenolic content of the resistant variety Sujiao 5 was significantly higher than that of the other varieties. The change in total flavonoids in resistant varieties between damaged and undamaged leaves were less than those in susceptible varieties. [Conclusion] The resistance of six different pepper varieties against the Q biotype whitefly appears related to SOD and POD activity and total phenolic content, but not to the total flavonoid content, of pepper leaves.