Isolation and evaluation of the biocontrol potential of Talaromyces spp. against rice sheath blight guided by soil microbiome.

Abstract

Rice sheath blight caused by Rhizoctonia solani is the major disease of rice that seriously threatens food security worldwide. Efficient and eco-friendly biological approaches are urgently needed since no resistant cultivars are available. In this study, fallow and paddy soils were initially subjected to microbiome analyses, and the results showed that Talaromyces spp. were significantly more abundant in the paddy soil, while Trichoderma spp. were more abundant in the fallow soil, suggesting that Talaromyces spp. could live and survive better in the paddy soil. Five isolates, namely TF-04, TF-03, TF-02, TF-01, and TA-02, were isolated from the paddy soil using sclerotia of R. solani as baits and were further evaluated for their activity against rice sheath blight. These isolates efficiently parasitized the hyphae and rotted the sclerotia even at higher water contents in sterilized sand and the soil. Isolate TF-04 significantly promoted rice growth, reduced the severity of rice sheath blight, and increased rice yield under outdoor conditions. Defense related genes were upregulated and enzyme activities were enhanced in rice treated with isolate TF-04. Our research supplies a microbiome guided approach to screen biological control agents, provides Talaromyces isolates to biologically control rice sheath blight. This article is protected by copyright. All rights reserved.