云南苹果白纹羽病原菌的分离与鉴定

为了明确云南苹果产区是否发生白纹羽病，本文按照柯赫氏法则，采用组织分离法和苹果枝条离体接种法，确定分离菌株的致病性，采用形态学和rDNA-ITS序列鉴定分离物的生物学归属。结果表明，分离菌株 STX1.E.3、TJX-6、Y8-8与ZTZS-6在离体条件下能侵染苹果枝条，并在枝条表面形成白色丝网状菌索和褐色的水渍状圆形病斑，它们都属于引起白纹羽病的褐座坚壳菌（Rosellinia necatrix（Hart.）Berl）。该病菌在云南省红河州泸西县、曲靖市马龙区、昆明市西山区和昭通市鲁甸县均有分布。这是云南省苹果白纹羽病的首次报道，对该病的发生规律和防治技术研究奠定了基础。

Isolation and identification of the pathogen of apple white root rot in Yunnan

To determine whether there is white root rot in Yunnan apple producing areas, the pathogen was isolated and confirmed by tissue isolation and in vitro inoculation on apple branches and by following the Koch''s postulate, and the pathogen was identified by morphology and rDNA-ITS sequence. The results showed that the isolated strains STX1.E.3, TJX-6, Y8-8 and ZTZS-6 could infect apple branches in vitro, and form white shoestring and brown and waterlogging lesion on the branch surface . They all belong to Rosellinia necatrix (Hart.) Berl causing white root rot. The pathogen distributes in Luxi County, Honghe Prefecture, Malong District, Qujing City, Xishan District, Kunming City and Ludian County, Zhaotong City. This is the first report on apple white root rot in Yunnan Province and set up a basis for the research on the occurrence regularity and control technology of the disease.