RHIZOPHAGUS INTRARADICES AND TOMATO-BASIL COMPANIONSHIP AFFECT ROOT MORPHOLOGY AND ROOT EXUDATE DYNAMICS IN TOMATO UNDER FUSARIUM WILT DISEASE STRESS

Combining the benefits of intercropping with arbuscular mycorrhizal fungi (AMF) can be an additional tool for managing the soil-borne diseases in sustainable land management systems. The present study was designed to investigate the influence of basil (Ocimum basilicum L.) as an intercropping partner and arbuscular mycorrhizal fungi (Rhizophagus intraradices: AMF) on tomato (Solanum lycopersicum L.) root morphology and exudation both in the presence and absence of Fusarium wilt (Fusarium oxysporum f. sp. lycopersici, FOL) disease stress. Experiments were conducted in a root compartment system. Our results indicated that intercropping tomato with basil did not only increase the plant biomass but also significantly reduced disease severity in tomatoes. Moreover, tomato plants intercropped with basil and co-inoculated with AMF and FOL had higher root lengths, volume and surface areas as compared to the plants in tomato-tomato combination. In vitro studies of FOL microconidia germination in tomato root exudates revealed significantly lower germination rate in the root exudates of AMF colonized tomatoes intercropped with basil than in exudates of tomato intercropped with tomato. In conclusion, intercropping basil with tomato successfully alleviates Fusarium wilt stress even without direct root contact. The addition of AMF increases the tolerance of the host plant towards Fusarium wilt by affecting tomato root morphology and exudation dynamics.

Automated summary

Intercropping basil with tomato can increase plant biomass and significantly reduce disease severity in tomatoes. Intercropped tomato plants have more developed roots and larger sizes compared to monocropped tomatoes. Adding arbuscular mycorrhizal fungi enhances the tolerance of host plants towards Fusarium wilt by influencing tomato root morphology and exudation dynamics.