Espinoza J G, Briceño E X, Chávez E R, Úrbez-Torres J R, Latorre B A
Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Casilla 306-22, Santiago, Chile.
Laboratorio de Micología, Servicio Agrícola y Ganadero, Lo Aguirre, Ministerio de Agricultura, Chile.
Plant Dis. 2009 Nov;93(11):1187-1194. doi: 10.1094/PDIS-93-11-1187.
Blueberry (Vaccinium spp.) plantings have significantly increased in Chile during the last decade and, currently, over 10,700 ha are cultivated throughout the country. Among other diseases, stem canker and dieback has been frequently observed in commercial plantations with incidences between 15 and 45%. The aim of this study was to identify and characterize Neofusicoccum spp. causing stem canker and dieback of blueberry in Chile. Three species, N. arbuti, N. australe, and N. parvum, were identified based on colony and conidia morphology, and nucleotide sequence analysis of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2). These Neofusicoccum spp. were found alone or coexisting with Pestalotiopsis spp., Truncatella spp., or Phomopsis spp. Koch's postulates showed all Neofusicoccum spp. isolated from infected plants to be pathogenic when inoculated on blueberry fruit and twigs using both mycelia and conidia suspension. All blueberry cultivars tested, including, Brigitta, Bluecrop, Brightwell, Duke, Elliott, Misty, and O'Neal, were susceptible to Neofusicoccum spp. infection. Pathogenicity tests showed N. parvum to be the most virulent species and Elliott to be the most susceptible cultivar. This report represents the first description of N. arbuti, N. australe, and N. parvum as canker-causing agents on blueberry in Chile.
在过去十年间，智利的蓝莓（越橘属）种植面积显著增加，目前全国种植面积超过10,700公顷。在商业种植园中，除其他病害外，茎溃疡和枝枯病频发，发病率在15%至45%之间。本研究旨在鉴定和表征导致智利蓝莓茎溃疡和枝枯病的新壳梭孢属真菌。基于菌落和分生孢子形态以及内部转录间隔区（ITS）区域（ITS1-5.8S-ITS2）的核苷酸序列分析，鉴定出三种新壳梭孢属真菌，即杨梅新壳梭孢、南方新壳梭孢和微小新壳梭孢。这些新壳梭孢属真菌单独存在，或与拟盘多毛孢属、截盘孢属或拟茎点霉属真菌共存。柯赫氏法则表明，从受感染植物中分离出的所有新壳梭孢属真菌，在使用菌丝体和分生孢子悬浮液接种蓝莓果实和嫩枝时均具有致病性。所有测试的蓝莓品种，包括布里吉塔、蓝丰、布赖特韦尔、公爵、艾略特、薄雾和奥尼尔，均对新壳梭孢属真菌感染敏感。致病性测试表明，微小新壳梭孢是毒性最强的物种，艾略特是最易感的品种。本报告首次描述了杨梅新壳梭孢、南方新壳梭孢和微小新壳梭孢是智利蓝莓溃疡病的致病因子。
