Potential use of Hanseniaspora uvarum in the control of Anthracnose in Phaseolus lunatus caused by Colletotrichum truncatum

Yeasts are widely used in the biological control of post-harvest diseases. However, their application in the management of foliar spots remains incipient. This study aimed to investigate the potential of yeasts in the biocontrol of anthracnose in Phaseolus lunatus by evaluating strains isolated from fruits and culms. A total of 42 strains were obtained, all of which inhibited in vitro mycelial growth of the phytopathogenic fungus Colletotrichum truncatum . The association between in vitro assays and disease control in plants was assessed by selecting seven contrasting strains based on their inhibition percentages. The strains were molecularly identified, tested for the production of inhibitory compounds (both soluble and volatile), and evaluated in interactions with both the pathogen and the host. The strains identified belonged to the species Hanseniaspora uvarum , H. opuntiae , Lachancea thermotolerans , Pichia kudriavzevii , and Nakaseomyces glabratus and produced soluble and volatile compounds capable of inhibiting the fungus. In interaction assays with the pathogen and P. lunatus , three strains reduced disease severity by 81%, two of which exhibited lower in vitro mycelial growth inhibition percentages. These three strains belonged to the species H. uvarum and N. glabratus . However, the H. uvarum strain was considered the most promising, as it poses no potential risk to human health. The strain's effectiveness in reducing disease symptoms was not associated with the production of soluble or volatile compounds. Thus, assays integrating both pathogen and host interactions are promising for identifying yeasts with potential for foliar disease biocontrol.