几种辣椒品种次生物质与抗侧多食跗线螨的关系

Relationships between several secondary substances in pepper varieties and the resistance to broad mite Polyphagotarsonemus latus( Banks)

为探讨辣椒品种次生物质与抗侧多食跗线螨Polyphagotarsonemus latus(Banks)的关系,以叶片危害指数为抗性评价指标,利用分光光度法检测了6个辣椒品种在侧多食跗线螨取食前后辣椒碱、多酚和单宁含量的变化。结果显示,在接螨前和接螨后7 d,未在辣椒叶片中检测到辣椒碱;接螨后14 d和21 d,叶片辣椒碱含量上升,但与叶片危害指数之间无显著相关性。接螨前辣椒叶片多酚和单宁含量与接螨后叶片危害指数之间存在显著负相关性,相关系数分别为-0.8410和-0.8714。与接螨前相比,接螨后7 d,抗性品种叶片多酚和单宁含量显著上升,而非抗性品种则显著下降;接螨后14 d和21 d,酚类含量开始下降;接螨后7、14和21 d叶片多酚和单宁含量平均上升率与叶片危害指数之间均存在极显著负相关性,相关系数分别为-0.9826和-0.9133。表明辣椒品种对侧多食跗线螨的抗性表现出组成和诱导抗性2种机制,辣椒品种多酚和单宁含量与抗性大小呈正相关。

To investigate the relationships between several secondary substances in pepper varieties and the resistance to broad mite Polyphagotarsonemus latus( Banks),the index of injured leaves was used as evaluation standard for resistance,and the changes of capsaicin,polyphenol and tannin in leaves of six pepper varieties fed by P. latus were determined by means of spectrophotometric colorimetry. The results showed that capsaicin was not detected in the tested pepper before feeding and 7 days after feeding treatments,and the contents of capsaicin significantly increased 14 and 21 days after feeding treatment,but the contents of capsaicin from six varieties were not significantly related to the index of injured leaves.The contents of polyphenol and tannin in leaves of six untreated varieties were significantly negatively related to the index of injured leaves with a correlation coefficient of- 0. 8410 and- 0. 8714,respectively. Compared with the contents before feeding treatment,the contents of polyphenol and tannin in the leaves of mite-resistant varieties increased significantly seven days after feeding treatment,while that of mite-susceptible varieties dropped sharply. However,the content of phenols declined 14 and 21 days after feeding treatment. There were significant negative correlation between the average increasing rates of polyphenol and tannin contents and the index of injured leaves 7,14 and 21 days after feeding treatment,with a correlation coefficient of- 0. 9826 and- 0. 9133,respectively. The resistance ofpepper varieties to P. latus consisted of constitutive resistance and induced resistance,and the contents of polyphenol and tannin in pepper varieties were positively related to the level of resistance.