Synergistic Effects of Clonostachys rosea Isolates and Succinate Dehydrogenase Inhibitors Fungicides against Gray Mold on Tomato

Abstract

Gray mold caused by Botrytis cinerea is a devastating disease in tomatoes. Site-specific fungicide application is still key to disease management; however, chemical control has many drawbacks. Here, the combined application of a biological agent, Clonostachys rosea, with newly developed succinate dehydrogenase inhibitors (SDHI) fungicides showed stronger synergistic effects than the application of SDHI fungicides alone on tomato gray mold control. C. rosea 67-1 has been reported as an efficient biological control agent (BCA) for B. cinerea. Little information is currently available about the combination of C. rosea and fungicides in the control of gray mold. By testing the sensitivity to fungicides with different action mechanisms, C. rosea isolates showed high tolerance to SDHI fungicides (1000 μg mL−1) on PDA, and the conidial germination rate was almost not affected under 120 μg mL−1 of fluxapyroxad and fluopyram. In greenhouse experiments, the control effect of the combination of C. rosea and fluxapyroxad or fluopyram against tomato gray mold was significantly increased than the application of BCA or SDHI fungicides alone, and the combination allows a two-fold reduction of both the fungicide and BCA dose. Further, the biomass of B. cinerea and C. rosea on tomato plants was determined by qPCR. For B. cinerea, the trend of detection level for different treatments was consistent with that of the pot experiments, and the lowest biomass of B. cinerea was found when treated with C. rosea combined with fluxapyroxad and fluopyram, respectively. For C. rosea, qPCR assay confirmed its colonization on tomato plants when mixed with fluopyram and fluxapyroxad. These results indicated that combining C. rosea 67-1 with the SDHI fungicides could synergistically increase control efficacy against tomato gray mold.

Diversity and antioxidant activity of endophytic fungi isolated from salam (Syzygium polyanthum)

“…This fungus lives in many types of habitats, with the highest frequency found in the soil. Therefore, as an excellent mycoparasite, C. rosea exhibits strong biological control capabilities against many fungal, nematode, and insect-plant pathogens (Piombo et al 2023;Song et al 2023;Venkatesan et al 2023). This behavior is according to the activation of several mechanisms, such as secreted enzymes to degrade the cell wall, antifungal secondary metabolites production, and plant defense systems induction.…”

Synergistic Effects of Chemical Fungicides with Crude Extracts from Bacillus amyloliquefaciens to Control Northern Corn Leaf Blight

“…Therefore, this study aimed to isolate crude extracts from the fermentation supernatant for the following exploration. A mixture of antifungal agents with different mechanisms is more likely to be a synergistic combination [27]. It can be speculated that the inhibition mechanism of the metabolites of B. amyloliquefaciens gfj-4 against E. turcicum may be quite different from that of commonly used chemical fungicides, so there is a high probability of developing new synergistic combinations.…”