Potential application of a marine-derived fungus, Talaromyces tratensis KUFA 0091 against rice diseases

The objective of this study was to evaluate antagonistic activity of Talaromyces tratensis KUFA 0091 against Alternaria padwickii (Ganguly) M. B. Ellis, Bipolaris oryzae (Breda de Haan) Shoem., Curvularia lunata (Wakk) Boedjin., and Fusarium moniliforme J. Sheld the causal agents of rice brown spot and dirty panicle. The in vitro results showed that among the tested pathogens, T. tratensis KUFA 0091 significantly (P < .05) inhibited the radial growth of B. oryzae in dual cultures on potato dextrose agar medium by 46% and forming an inhibition zone 13-15 mm in width. The crude extract of the antagonistic fungus completely inhibited the radial growth of all tested pathogens at a concentration of 10 g L-1 and significantly (P < .05) inhibited the mycelial growth of B. oryzae by 53% at 1 g L-1. Under greenhouse conditions, the highest reductions in the incidences brown spot and dirty panicle were 56.74% and 60% when treated with crude extract at 5 g L-1 and spore suspension of T. tratensis at 10(6) spores mL(-1), respectively. Under field conditions, the greatest reduction in the incidence of dirty panicle was 50-60% when treated with spore suspension. The highest yield weight was obtained when crude extract was applied twice at 10 g L-1; the yield weight was 31.71% greater than that of the negative control treatment. The results of this study indicate that T. tratensis KUFA 0091 is a promising biological control agent and a good candidate for controlling the brown spot and dirty panicle diseases of rice.