利用玉米与其他作物间作增加农田系统的作物多样性是我国西南地区降低病虫危害的重要种植模式，但对玉米间作控制病害的化感效应和原理还未展开深入研究。前期对玉米/辣椒间作控制辣椒疫病的研究表明，玉米根系分泌物在控制疫霉菌传播方面起着重要作用，其中苯并噁嗪类化合物（BXs）丁布和门布对疫霉菌具有抑制活性。但BXs在间作控制辣椒疫病中的具体效应及间作对BXs合成的诱导调控机制还不清楚。本项目拟利用根系能分泌BXs的玉米品种、BXs合成关键酶（Bx1）缺失突变体及其野生型亲本开展研究，以明确（1）玉米不同类型根系分泌BXs的能力及其对辣椒疫霉菌的抑菌活性；（2）BXs在玉米/辣椒间作控制辣椒疫病中的具体作用；（3）间作对玉米BXs合成诱导的调控因子及其机制。通过这些研究探明玉米根分泌物BXs在玉米与其它作物间作控制疫病中的化学生态功能及其影响因素，为合理地利用玉米间作控制病害提供理论支撑。

Maize and other crop intercropping is an important mode to increase diversity for disease control in Southwest China. However, allelopathic effect and its mechanism for disease control in this intercropping system are still unknown. Our previous studies indicated that maize and pepper intercropping can effectively restrict the spread of Phytophthora capsici in field, depending on the chemical barrier formed by root exudates in rhizosphere. The secondary metabolites Benzoxazinoids secreted from maize root may play an important role in disturbing the infection process of Phytophthora capsici. However, the control effect of Benzoxazinoids on pepper Phytophthora blight and its regulatory mechanism in intercropping system are still unclear. In this study, we will utilize the maize hybrid varieties, wild type and its bx1 mutant lines to investigate (1)the capability of BXs secreted from different root type of maize and their antifungal activity to Phytophthora capsici,(2)the role of BXs for pepper Phytophthora blight control in maize and pepper intercropping system,(3)the effect of maize and pepper intercropping on the biosynthesis of BXs and its regulatory mechanism. Based on these studies, we can discover the chemical function of BXs on Phytophthora blight disease control and their regulatory factors in intercropping system. Thus, it is very important for us to scientifically utilize maize intercropping with other crop for disease control.