Intercropping influences component and content change of flavonoids in root exudates and nodulation of Faba bean

Flavonoids produced by legume roots are signal molecules acting as nod gene inducers for the symbiotic rhizobium partner. Nevertheless, the changes of flavonoids in root exudates in intercropping system are still unknown. Based on pot experiment of faba bean and wheat intercropping, here we showed that faba bean and wheat intercropping increased the nodules number and dry weight, dry weight per nodule of faba bean compared with those found in monocropping, and the increase of faba bean nodulation was likely caused by the enhancement with flavonol, isoflavone, chalcone and hesperetin in its root exudates. It also promoted exudation of five types of flavonoids by wheat compared with monocropping. Our findings suggest that the flavonoids in root exudates have a positive effect on the nodulation and nitrogen fixation of faba bean in faba bean and wheat intercropping.