Development of a biological control strategy against fusariosis and rabies of Fuentesaúco-Chickpea (PGI) through the use of the Trichoderma fungus

The Protected Geographical Indication (PGI) Fuentesaúco-Chickpea (F-C) includes a legume crop developed in the south of the province of Zamora (Spain), which is of great agronomic, economic and cultural importance for the area, as well as globally. Its cultivation is mainly affected by the fungal diseases called fusariosis (caused by Fusarium oxysporum f. sp. ciceri) and rabies (caused by Ascochyta rabiei). Through an in vitro antagonism study we were able to select the species Trichoderma atroviride, T. hamatum, T. harzianum and T. koningii as the most effective against both pathogens, thanks to mechanisms of action such as mycoparasitism, antibiosis and/or competition for space and/or nutrients. Subsequently, these four Trichoderma species were used in studies with F-C plants and both pathogens. Using this methodology, we described how T. atroviride and T. koningii were able to control F. oxysporum f. sp. ciceri both directly and by activating plant defenses, in the case of T. koningii. On the other hand, the species T. hazianum and T. koningii were able to significantly reduce foliar infection with A. rabiei, by activating systemic plant defence responses. Regarding the productivity of F-C, the species T. hamatum and T. koningii were able to significantly increase the formation of grains in each plant. Therefore, T. koningii is capable of controlling both pathogens under greenhouse conditions, in addition to increasing their productivity.