Biocontrol of Corynespora cassiicola in soybean using a new phenethyl alcohol-producing Meyerozyma caribbica strain

Abstract

Corynespora cassiicola is a hazardous fungal pathogen that causes target spot disease in soybean. Numerous resistant C. cassiicola strains have emerged during recent years, leading to uncontrolled spreads and enormous economic losses in several soybean production areas. For these reasons, new methods for the control of this pathogen are urgently needed. In this study, a new Meyerozyma caribbica strain, NJC41, was isolated from C. cassiicola-infected soybean plants in China and identified by ITS and LSU sequencing. NJC41 inhibited C. cassiicola mycelial growth, and showed high colonization ability in soybean pods, maintaining its population for one week. NJC41 produced antifungal phenethyl alcohol, which was detected at 44.6 μg/mL in NJC41 secretions, and competed for space and nutrients with C. cassiicola. Curative application of 1 × 109 cells/mL NJC41 reduced C. cassiicola symptoms by 47.1%, providing higher curative efficacy than commercial fungicide carbendazim (29.8% lesion length inhibition). This study reveals the first biocontrol method for the management of target spot disease in soybean.