P-375 - Effectivity of secondary metabolites from Clonostachys rosea and rhizophaga as plant growth promoters

Clonostachys rosea is a soil-borne root endophyte showing great potential for agricultural applications as a mycoparasitic biological control and biofertilizer. Clonostachys rhizophaga is a closely related, seldom researched fungal endophyte that shows similar promise. Hundreds of different secondary metabolites have been reported from the genus, making it of special interest within ecological solutions research. C. rosea has been tested as a biological control against insects, bacteria, and other fungi. However, the potential bioactivity of secondary metabolites produced by these fungi remains unexplored.  Here, we studied the biological activity of C. rosea and C. rhizophaga on different plants. Pure cultures of each were isolated from soybean roots and crude extracts were obtained by filtering through a Buchner funnel and a PES membrane.  First, we investigated the effects of C. rosea and rhizophaga raw filtrates on plant root length and chlorophyll content of a variety of host plants, including soybean, chickpea, tomato, and black-eyed-pea. Plants were exposed to different concentrations of the filtrates (25-fold, 50-fold, and 100-fold dilutions). A significant increase in plant root length was observed in all plants treated with Clonostachys spp. secondary metabolites. No statistically significant impact on chlorophyll content of plant leaves was observed between control and Clonostachys treatments. These results suggest that SMs of C. rosea and C. rhizophaga promote plant growth in roots of many agricultural plants.