Beneficial effects of Trichoderma on nitrogen fixation and root rot disease symptoms in pea

Summary

Pea (Pisum sativum L.) is a grain legume used as a valuable source of protein for food and feed. In addition, pea provides important agro-ecological benefits for sustainable cropping systems by increasing soil fertility. This is due to its ability to fix atmospheric nitrogen in symbiosis with diazotrophic soil bacteria, known as rhizobia, that induce the formation of root nodules. However, the cultivation of pea is severely compromised by various root rot pathogens. Fusarium solani is one of the mayor root rot pathogens of pea (Wille et al., 2020). Species of the genus Trichoderma are widely studied for their ability to promote plant health and antagonise a wide range of pathogens, including F. solani (Sharma 2020). However, it is not known how Trichoderma affects the rhizobia-legume symbiosis, notably the relationship between nitrogen fixation capacity and fungal resistance in legumes. In addition, it was shown that F. solani is stimulated by the same group of plant-exuded flavonoids that are involved in the interaction with Rhizobium leguminosarum bv. viciae, the rhizobial symbiont of pea (Ruan et al., 1995). This points at complex plant-microbe feedbacks eventually determining plant fitness