Authors
Z. F. Zhang and
H. Y. Li, Institute of Biotechnology, Zhejiang University; and
Z. H. Shi, Institute of Insect Science, Zhejiang University, Hangzhou, Zhejiang 310029, China
Red bayberry (Myrica rubra Sieb. et Zucc) is a special fruit produced in southeastern China. Heavy losses due to postharvest rot and short shelf-life have negatively affected farmers' incomes. In June 2007, a survey was conducted to determine the causal agents of red bayberry (cv. Dongkui) rot in Linhai City, Zhejiang Province. Only a few soft rot fruits with typical gray mold of Botrytis cinerea were found on trees, but 74% (266 of 360) of the fruits that appeared disease free during harvest showed a mass of gray mold after 5 days in storage at 22°C. Brown conidiophores bore botryose heads of hyaline, ellipsoid, unicellular conidia, measuring 9.1 to 16.1 × 8.6 to 11.0 μm. Mycelia were initially whitish and turned gray with age. Black, irregular sclerotia were formed in potato dextrose agar medium. Such features suggested B. cinerea infection (1). Pathogenicity was confirmed by inoculation of 20 healthy red bayberries with a conidial suspension (106/ml); 100% were infected and masses of gray mold were formed 4 days after inoculation. No mock-inoculated fruits were infected. To confirm involvement of B. cinerea, the internal transcribed spacer (ITS) region was amplified with primers ITS4/ITS6 (2). The sequence (Accession No. AM884742) matched 100% to B. cinerea sequences deposited in Genbank (Accession Nos. EF207415, EF207414, and EF207413). To our knowledge, this is the first report of red bayberry rot caused by B. cinerea in China.
References: (1) J. Y. Lu. Phytopathogenic Fungi. Chinese Agricultural Publishing, Beijing, 1995. (2) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997.
