Kong C S, Qiu X L, Yi K S, Yu X F, Yu L
Laboratory of Plant Pathology, Agricultural Environment and Resource Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650205, China.
College of Agronomy, Kunming University, Kunming, 650214, China.
Plant Dis. 2010 Nov;94(11):1373. doi: 10.1094/PDIS-05-10-0393.
In May 2008, symptoms of blueberry blight were observed on half-high blueberry (Vaccinium corymbosum L.) in a plant nursery in Anning, Yunnan Province. Symptoms included dieback and bud and branch blight. Symptomatic plant samples were washed with running tap water, disinfected with 2% sodium hypochlorite and then 70% alcohol, rinsed in sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 26°C. Conidia forming on PDA were hyaline, granular, fusoid to ellipsoid, widest in the upper third with an obtuse apex and flattened, subtruncate base, and 18 to 21 × 4.5 to 8 μm. The pathogen was also identified to the species level by sequencing the ribosomal internal transcribed spacer regions 1 and 2 (ITSI-5.8S-ITS2) and the translation elongation factor 1-alpha (EF1-α). BLAST searches at GenBank showed the highest nucleotide sequence identity with Neofusicoccum vitifusiforme reference sequence (ITS: >98%, EF638785; EF1-α: 100%, EF638744 and AY343343). Representative sequences of isolates from both regions were deposited in GenBank (ITS: Accession No. HM131604; EF1-α: Accession No. HM454277). Pathogenicity tests were conducted on 2-year-old blueberry seedlings (half-high blueberry). Mycelial plugs (3 mm in diameter) of N. vitifusiforme from actively growing colonies (PDA) were applied to same-size bark wounds in the center of the stems. Inoculation wounds were wrapped with Parafilm. Control seedlings received sterile PDA plugs. Inoculated and control seedlings (five each) were kept in a greenhouse and watered as needed. After 2 weeks, all of the inoculated but none of the control blueberry seedlings showed dark vascular stem tissue. N. vitifusiforme was reisolated from symptomatic tissues, thus fulfilling Koch's postulates. N. vitifusiforme has been reported as a pathogen of olive (2), plum, peach (1), and grapevine (3). To our knowledge, this is the first report of N. vitifusiforme on blueberry in China as well as worldwide. References: (1) U. Damm et al. Mycologia 99:664, 2007. (2) C. Lazzizera et al. Plant Pathol. 57:948, 2008. (3) J. M. van Niekerk et al. Mycologia 96:781, 2004.
2008年5月，在云南省安宁市一家苗圃的半高丛蓝莓（Vaccinium corymbosum L.）上观察到蓝莓枯萎病症状。症状包括枝条枯死以及芽和枝条枯萎。有症状的植株样本先用自来水冲洗，再用2%次氯酸钠消毒，然后用70%酒精消毒，在无菌蒸馏水中冲洗，接种到马铃薯葡萄糖琼脂（PDA）平板上，并在26°C下培养。在PDA上形成的分生孢子无色透明、颗粒状、梭形至椭圆形，在三分之一上部最宽，顶端钝圆，基部扁平、近截形，大小为18至21×4.5至8μm。还通过对核糖体内部转录间隔区1和2（ITSI - 5.8S - ITS2）以及翻译延伸因子1 - α（EF1 - α）进行测序，将病原菌鉴定到种水平。在GenBank上进行的BLAST搜索显示，与葡萄座腔菌（Neofusicoccum vitifusiforme）参考序列的核苷酸序列同一性最高（ITS：>98%，EF638785；EF1 - α：100%，EF638744和AY343343）。来自两个区域的分离株的代表性序列已存入GenBank（ITS：登录号HM131604；EF1 - α：登录号HM454277）。对2年生蓝莓幼苗（半高丛蓝莓）进行了致病性测试。从活跃生长的菌落（PDA）上切取直径3mm的葡萄座腔菌菌丝块，接种到茎干中部相同大小的树皮伤口处。接种伤口用Parafilm包裹。对照幼苗接种无菌PDA块。接种和对照幼苗各5株置于温室中，按需浇水。2周后，所有接种的蓝莓幼苗均出现维管束茎组织变黑，而对照幼苗均未出现。从有症状的组织中重新分离出葡萄座腔菌，从而满足了柯赫氏法则。葡萄座腔菌已被报道为橄榄（2）、李、桃（1）和葡萄（3）的病原菌。据我们所知，这是葡萄座腔菌在中国以及世界范围内首次在蓝莓上的报道。参考文献：（1）U. Damm等人，《真菌学》99：664，2007。（2）C. Lazzizera等人，《植物病理学》57：948，2008。（3）J.M. van Niekerk等人，《真菌学》96：781，2004。
