Characterization of Botryosphaeria dothidea and Lasiodiplodia pseudotheobromae from English Walnut in China

摘要

China is the largest walnut producer in the world, and walnut trees, especially English walnut, are widely distributed in the country. Species of Botryosphaeriaceae include important plant pathogens that can cause diseases on many tree crops including English walnut. Recently, disease symptoms caused by Botryosphaeriaceae were observed on English walnut branches or kernels from Beijing, Henan and Sichuan provinces in China. Based on morphological characteristics and phylogenetic analyses of the ITS rDNA sequences and translation elongation factor 1-alpha (TEF-1) gene regions, Botryosphaeria dothidea and Lasiodiplodia pseudotheobromae were identified. Pathogenicity tests showed that both species are virulent to English walnut. To our knowledge, this is the first report of L.pseudotheobromae infecting English walnut in the world.