不同抗性短枝木麻黄种源苗木接种青枯病菌后酚类物质含量的变化

Changes in Phenols Contents in Casuarina equisetifolia Provenances with Different Resistibility Infected by Ralstonia solanacearum

摘要:

为了解短枝木麻黄（Casuarina equisetifolia）抗青枯病的机理，对接种青枯病菌（Ralstonia solanacearum）后短枝木麻黄的单宁和黄酮含量变化进行了分析。结果表明，不同抗性短枝木麻黄种源小枝的总酚和单宁含量呈现不同的变化趋势，高抗、中抗种源均呈现先升高后降低的变化趋势，峰值均约为126 mg g^-1，但中抗种源的峰值出现时间较晚，而易感种源则呈逐渐升高趋势。抗、感种源木麻黄接种青枯菌后，小枝中缩合单宁含量均呈现逐渐升高的趋势，但高抗种源的缩合单宁含量均显著高于易感种源，增加70.33%。抗性种源黄酮含量呈S型上升趋势，易感种源则持续缓慢升高。这表明接种青枯病菌后，抗、感短枝木麻黄种源表现出不同的防御特征，次生物质含量增幅越大，抑菌抗氧化能力越强，短枝木麻黄表现出的抗性越强。

Abstract:

In order to understand the resistance mechanism of casuarinas (Casuarina equisetifolia) against Ralstonia solanacearum, the changes in contents of tannin and phenols in casuarinas infected by R. solanacearum were analyzed. The results showed that the change trends of tannin and phenols contents in provenances with different resistibility were different. The contents of tannin and phenols in high- and media-resistant provenances increased at first and then decreased with the peak of 126 mg g^-1, and the peak of media-resistant provenances came later. The susceptible provenances showed rising trend. After infected with R. solanacearum, the condensed tannin content increased gradually in three provenances, and that in the high-resistant provenances were 70.33% higher than that in susceptible provenances. The content of flavone in resistant provenances showed S type rising trend, while that in susceptible provenances increased slowly. Therefore, it was demonstrated that there were different defense mechanisms between resistant and susceptible provenances. The greater the content of secondary compounds increase, the stronger bacteriostasis and antioxidant activities, Casuarina equisetifolia would show higher resistance to bacterial wilt.