苯并噻二唑对香蕉枯萎病的诱导抗性

Induced resistance of benzothiadiazole to banana fusarium wilt

采用含药培养基生长速率法测定苯并噻二唑(benzothiadiazole,BTH)对香蕉枯萎病菌4号生理小种(Fusarium oxysporumf.sp.cubense race 4,Foc 4)的室内毒力,结果表明BTH对Foc 4的EC50为929.9μg/mL,与杀菌剂多菌灵相比,其作用十分微弱。然后,在温室条件下,采用盆栽试验测定BTH对香蕉枯萎病的防治效果,结果表明BTH质量浓度为50μg/mL时的诱抗效果最好,防治效果可达到66.6%,且随着浓度的升高其防治效果逐渐降低。最后,在温室条件下测定BTH处理香蕉苗后,其体内6种防御酶活性的变化,结果表明BTH可以提高香蕉苗体内多种防御酶的活性。

Induced resistance of benzothiadiazole （BTH）, a new inducer of plant disease resistance, to banana fusarium wilt caused by Fusarium oxysporurn f. sp. cubense race 4： （Foc 4）, was investigated. Firstly, in vitro toxicity of BTH to Foc 4 was tested with the growth rate method. The results showed that the EC50 of BTH was 929. 9 μg/mL, showing a very weak antifungal effect compared to carbendazim, a routine fungicide. Secondly, the sensitivity of banana fusarium to BTH in three different concen- trations was studied in vivo, and the results indicated that 50μg/mL of BTH had the greatest effect of induced resistance with the disease control efficiency of 66.6 %, and its control efficiency was descending gradually along with the increase of BTH concentration. Finally, the changes in activities of six defen- sive enzymes in banana plantlets treated with BTH were determined, and the results demonstrated that BTH could increase the banana resistance to banana fusarium wilt by improving the activities of several defense-related enzymes. Taken together,BTH is a promising plant disease resistance inducer by activa- ting the defense response of banana plantlets. Therefore, BTH has a potential application prospect in the control of banana fusarium wilt disease.