Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada.
Department of Plant Pathology, University of California, Davis, CA 95616, U.S.A.
Plant Dis. 2020 Jul;104(7):1908-1917. doi: 10.1094/PDIS-09-19-1979-RE. Epub 2020 May 20.
Field surveys conducted throughout California olive-growing regions in 2008 and 2009 resulted in a collection of 101 -like isolates from olive twig and branch dieback symptoms. isolates were isolated from multiple cvs. in different olive orchards in Fresno, Madera, Merced, Napa, Riverside, Santa Barbara, Sonoma, Tulare, and Ventura counties. Taxonomic studies of macro- and microscopic structures along with multigene phylogenetic analyses of the internal transcribed spacer region, including the 5.8S rDNA (ITS1-5.8S-ITS2), and fragments of the translation elongation factor 1-α, beta-tubulin, and actin genes identified two species, and sp. nov. Pathogenicity studies conducted in mature olive trees cvs. Manzanillo and Sevillano showed both species to be pathogenic and able to cause vascular necrosis and cankers in olive branches. This study adds to the current knowledge on the etiology of olive twig and branch dieback and provides new important information for the development of effective control strategies against canker diseases affecting olive in California.
2008 年和 2009 年在加利福尼亚橄榄种植区进行的实地调查，从橄榄小枝和树枝枯萎症状中收集了 101 株类似的分离株。这些分离株是从弗雷斯诺、马德拉、默塞德、纳帕、河滨、圣巴巴拉、索诺玛、图莱里和文图拉县不同橄榄园的多个品种中分离出来的。宏观和微观结构的分类学研究以及包括 5.8S rDNA（ITS1-5.8S-ITS2）在内的内部转录间隔区的多基因系统发育分析，以及翻译延伸因子 1-α、β-微管蛋白和肌动蛋白基因片段的分析，确定了两个种， 和 sp. nov. 在成熟的橄榄树品种 Manzanillo 和 Sevillano 上进行的致病性研究表明，这两个种都是病原性的，能够引起橄榄树枝的血管坏死和溃疡。本研究增加了对橄榄小枝和树枝枯萎病因的现有认识，并为制定针对加利福尼亚橄榄溃疡病的有效控制策略提供了新的重要信息。
