Antifungal activity of rapamycin on Botryosphaeria dothidea and its effect against Chinese hickory canker. Issue 1 (27th August 2020)

• Record Type: Journal Article
• Authors: Jiang, Hong; Rao, Yuxin; Mei, Li; Wang, Yongjun
• Is Part Of: Pest management science. Volume 77:Issue 1(2021)
• Page Start: 425
• Page End: 431
• Publication Date: 2020-08-27
• Subjects: EC50 -- alternative control -- Botryosphaeria canker -- CMC/PVA formulation -- Carya cathayensis; Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.6035
• Languages: English
• ISSNs: 1526-498X

Abstract

Abstract: BACKGROUND: The trunk canker caused by Botryosphaeria dothidea is a devastating disease for Chinese hickory ( Carya cathayensis ) in China. Chemical fungicides are commonly and repeatedly applied to control the disease; however, fungicide application raises major environmental and food safety issues. Ecofriendly biocontrol alternatives were urgently needed. Herein, the antifungal activity of a natural secondary metabolite, rapamycin, against B. dothidea and the effect of a rapamycin‐producing Streptomyces hygroscopicus on C. cathayensis canker were investigated. RESULTS: The 50% effective concentrations (EC50 ) of rapamycin against mycelial growth and spore germination on the potato dextrose agar were 5.1 × 10 −3 and 5.5× 10 −2 μg mL –1, respectively, which were much lower than the EC50 values of thiophanate‐methyl. The hyphae of B. dothidea exhibited premature aging and wrinkling after treatment with rapamycin at 5.0 × 10 −3 μg mL –1 . A rapamycin‐producing bacterium S. hygroscopicus LYJ637 was batch produced and formulated in a carboxymethylcellulose/poly (vinyl alcohol) (CMC/PVA) blend and used for testing the efficiency of the bacterium in controlling Botryosphaeria canker in C. cathayensis . S. hygroscopicus exhibited high stability in the CMC/PVA blend. Results of a 3‐year field experiment suggested that rapamycin formation reduced the occurrence of both developed cankers and new cankers, with an efficacy comparable to the treatment with thiophanate‐methyl. CONCLUSION: The rapamycin‐producing S. hygroscopicus LYJ637 carried in a CMC/PVA blend prevented effectively Botryosphaeria canker on Chinese hickory, which provides an alternative approach to chemical control strategies. Abstract : Antifungal activity of rapamycin against Botryosphaeria dothidea (left column) and control of Botryosphaeria canker on Chinese hickory by a rapamycin‐producing bacterium Streptomyces hygroscopicus LYJ637. © 2020 Society of Chemical Industry