Intercropping can effectively control some plant soil-borne diseases. However, few studies on intercropping have focused on forage grass as companion plants. In this experiment, Festuca arundinacea (tall fescue) was selected as the intercropping forage to explore whether it could control tomato stem rot. We found that: (1) tomato intercropped with tall fescue had a significantly lower disease incidence and disease index of tomato stem rot than sole tomato; (2) the antifungal activities of the root exudates of tomato and tall fescue in intercropping system were significantly higher than those of sole tomato or tall fescue. Meanwhile, it was inferred that the main allelochemicals might be cyclohexane-1, 2-diol and putrescine based on the GC-MS analysis of root exudates of tall fescue. (3) RNA-seq suggested that intercropping with tall fescue significantly upregulated the expression of genes related to pathogenesis-related proteins and hormone metabolism of tomato compared to those in sole tomato.

间作可以有效控制一些植物性土传病害。然而，关于间作的研究很少集中在草料作为伴生植物。在这个实验中，金合欢（高羊茅）被选作间作饲料，以研究它是否可以控制番茄茎腐。我们发现：（1）套种高羊茅的番茄的番茄发病率和病害指数明显低于单一番茄。（2）间作系统中番茄和高羊茅根系分泌物的抗真菌活性明显高于单独番茄或高羊茅。同时，根据高羊茅根分泌物的GC-MS分析，推测主要的化感物质可能是环己烷-1、2-二醇和腐胺。（3）RNA-seq提示，与单独的番茄相比，高羊茅间作显着上调了番茄发病机理相关蛋白和激素代谢相关基因的表达。