Inhibitory Effect of the Extracts from Sunflower Disk and Stalk on Fusarium Sulphureum Causing Potato Dry Rot.

Potato (Solanum tuberosum L.) dry rot due to fungal infections causes the loss of a significant amount of potatoes. In this study, the antifungal effects of sunflower (Helianthus annuus L.) extracts against Fusarium sulphureum were investigated. The results of in vitro antifungal tests showed that all four sunflower extracts significantly inhibited the growth of F. sulphureum. Notably, the optimal inhibitory concentrations of ethyl acetate extract from sunflower disk (EESD), ethyl acetate extract from sunflower stalk (EESS), petroleum ether extract from sunflower disk (PESD) and petroleum ether extract from sunflower stalk (PESS) against F. sulphureum were 160 mg/mL, 160 mg/mL, 240 mg/mL, and 240 mg/mL, respectively. In addition, these extracts significantly inhibited the activities of polygalacturonase (PG), polymethyl-galacturonase (PMG), carboxymethyl cellulase (Cx), and β-glucosidase (β-Glu) secreted by F. sulphureum in three potato varieties: Longshu No.7, Longshu No.10 and Xindaping. These results provide a theoretical foundation for the biological control of potato dry rot. [ABSTRACT FROM AUTHOR]