几种生化物质与西瓜抗蚜性的相关性

为了初步探讨西瓜抗蚜性的营养与次生代谢物质防御效应,采用分光光度法测定并分析了几种生化物质与西瓜抗蚜性的相关性。结果表明,抗性品种黑皮、绿美人、黑美人和惠兰的游离氨基酸、脯氨酸和可溶性氮含量分别为2.22~2.27、0.23~0.26和1.88~3.03 mg/g,显著低于感性品种金美人、小玲、甜美人和花绿的3.24~3.83、0.67~0.87和5.26~5.82 mg/g;抗性品种的糖/氮比为5.38~7.94,显著高于感性品种;抗、感品种间可溶性糖和维生素C(Vc)含量无显著差异;瓜蚜为害4 d后的抗性品种叶组织中的总酚和单宁酸含量显著增加,感性品种显著降低;丙二醛含量增加幅度显著高于抗性品种。研究表明,西瓜品种抗蚜性与糖/氮比及总酚、单宁酸含量均呈显著正相关,与可溶性氮、游离氨基酸、脯氨酸及丙二醛含量均呈显著负相关,但与可溶性糖和Vc含量无显著相关性。

The correlation between several chemical substances and watermelon resistance to Aphis gossypii

To understand the defense effects of nutrients and secondary metabolites for watermelon resistance to Aphis gossypii Glover,the correlation between several chemical substances and watermelon resistance to A.gossypii was studied by using spectrophotometric method. The results showed that the contents of free amino acids, proline and soluble nitrogen in resistant cultivar leaves from Heipi, Lümeiren, Heimeiren and Huilan were 2.22-2.27, 0.23-0.26 and 1.88-3.03 mg/g, respectively, significantly lower than those in susceptible cultivar leaves of Jinmeiren, Xiaoling, Tianmeiren and Hualü (3.24-3.83, 0.67-0.87 and 5.26-5.82 mg/g, respectively). The ratio of sugar to nitrogen in resistant cultivar leaves was 5.38-7.94,which were significantly higher than those in susceptible cultivar leaves. The contents of vitamin C (Vc) and sugar were not significantly different between resistant and susceptible cultivars. The contents of total phenol and tannic acid significantly increased in resistant cultivar leaves and significantly decreased in susceptible cultivar leaves damaged by A. gossypii for four days. The contents of malondialdehyde in susceptible cultivar leaves damaged by A. gossypii for four days increased significantly higher than those in resistant cultivar leaves. The results indicated that the ratio of sugar to nitrogen and the contents of total phenol and tannic acid had a positive correlation with watermelon resistance to A. gossypii, while the contents of nitrogen, free amino acids, proline and malondialdehyde had a negative correlation with watermelon resistance to A. gossypii, but the contents of Vc and soluble sugar had no correlation with watermelon resistance to A. gossypii.