Acta Agriculturae Zhejiangensis ›› 2026, Vol. 38 ›› Issue (1): 105-113.DOI: 10.3969/j.issn.1004-1524.20241081

• Plant Protection • Previous Articles     Next Articles

Isolation, identification and control of the pathogen causing leaf spot disease on hydrangea

CHEN Jingjing1(), ZHANG Yu1, WEN Lianhao1, LIU Guangyan1, ZHOU Mei1, LI Zhengmin1, XIONG Haiyan1, YANG Zhenyi2, YANG Zenghua2, TONG Yi2, WANG Chao1,*()   

  1. 1. Yunnan Province Engineering Research Center for Functional Flower Resources and Industrialization, Southwest Research Center for Landscape Architecture Engineering (State Forestry and Grassland Administration), Yunnan Province South and Southeast Asia Joint R&D Center of Economic Forest Full Industry Chain, Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province, College of Landscape and Horticulture, Southwest Forestry University, Kunming 650224, China
    2. Kunming Yang Chinese Rose Gardening Co., Ltd., Kunming 652501, China
  • Received:2024-12-11 Online:2026-01-25 Published:2026-02-11

Abstract:

In order to identify the pathogenic fungus of hydrangea leaf spot disease and its biological characteristics, and explore suitable control methods, tissue isolation was conducted on leaf spot samples of hydrangea cultivar Mme E Mouilliere, and the pathogenic fungus was purified, and verified based on Koch’s rule. Phylogenetic tree analysis was constructed using multi-gene sequences (ITS, LSU, TEF1) to identify the pathogenic fungus. Meanwhile, the mycelial growth rate method was adopted to investigate the effects of temperature, culture media, pH value, carbon source, nitrogen source, and photoperiod on the mycelial growth of the pathogenic fungus, and its lethal temperature was determined. Additionally, the inhibitory effects of 7 chemical fungicides on the fungus were tested. The results showed that the pathogenic fungus causing hydrangea leaf spot disease was identified as Amanita shennongjiana. Its mycelia grew well under the following conditions: temperature of 25 ℃, potato dextrose agar (PDA) medium, pH value of 5, and 12 h light/12 h dark alternation daily. Its optimal carbon source was sucrose, with a preference for nitrogen-free conditions. The lethal temperature of the fungus was 65 ℃ for 10 minutes. Under laboratory conditions, 80% ethylicin and 80% Bordeaux mixture exhibited better inhibitory effects on the fungus, with their median effective concentrations (EC50) being 1.948 9 mg·L-1 and 1.591 8 mg·L-1, respectively. This study is the first report of hydrangea leaf spot disease caused by Amanita shennongjiana in China.

Key words: hydrangea, leaf spot disease, Amanita shennongjiana, biological characteristic, screening of fungicide

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