First Report of Anthracnose on Boehmeria nivea Caused by Colletotrichum higginsianum in China.
First Report of Anthracnose on Boehmeria nivea Caused by Colletotrichum higginsianum in China.
复制标题
DOI：
10.1094/pdis-04-11-0356
复制
发表时间：
2011-09
期刊：
影响因子：
4.5
通讯作者：
X. X. Wang-X.;J. Chen;B. Wang;L. J. Liu;X. Huang;S. Ye;D. Peng
中科院分区：
文献类型：
--
作者：
X. X. Wang-X.;J. Chen;B. Wang;L. J. Liu;X. Huang;S. Ye;D. Peng
苎麻（Boehmeria nivea（L.）Gaud）炭疽病被认为是苎麻传播最广泛、破坏性最强的疾病之一。这种疾病在温暖和潮湿的条件下最严重。在中国，苎麻炭疽病的发生面积约为10，000公顷，平均产量损失20%，在某些地区高达55%（3）。2010年9月，在湖北省咸宁市附近的耕地中观察到典型的炭疽病症状。病叶上的病斑最初是小的、分散的、蓝白色的和水浸泡的。随着病情的发展，叶片上出现不规则的斑点，斑点中心变成灰色，边缘变成棕色。病变直径约为1 - 3 mm。最初，股骨柄上的病变呈梭形，然后扩大，导致股骨柄断裂。叶和茎组织相邻，并包括病变表面消毒在0.1%的次氯酸钠，然后种植在马铃薯葡萄糖琼脂（PDA）加草酸抑制细菌生长。将平板在25°C下孵育3至5天，直至出现粉红色孢子团，并具有许多密集的黑色刚毛簇。在PDA上，该真菌最初产生具有橙子分生孢子团的灰色菌落，然后在5天后菌落变黑。孢子为单细胞，无色，直，椭圆形，两端钝，10.0 ~ 20.0 × 3.0 ~ 5.0 μm，平均大小为15.8 ± 2.4 × 4.6 ± 0.4 μm，长宽比为3.47 ± 0.62。刚毛暗褐色，1 ~ 3隔。这些形态特征与HigginsianumSacc（1）一致。用引物ITS 1和ITS 4（GenBank登录号：JF 830783）对该真菌的ITS 1、5.8S和ITS 2序列进行分析，与多个分离株的序列相似性达99%。higginsianum（GenBank登录号：GU 935872和AB 042303）。在致病性试验中，用代表性真菌分离物的分生孢子悬浮液（1 × 106个分生孢子/ml）喷洒来自10天龄、30 cm高的苎麻植株的两侧叶片。该实验重复三次。将接种的植物在人工气候室中温育，其中光周期为12小时，温度为25至28°C，相对湿度为90%。接种后三天，在所有接种的叶片上观察到褐斑和水浸损伤，但在水处理的对照植物上没有观察到症状。科赫的假设通过重新分离C. Higginsianum病叶。C.已知Higginsianum在芸苔属和萝卜属的许多栽培品种上引起炭疽病叶斑病，但至今未见引起苎麻炭疽病的报道。C. boehmeriae Sawada和苎麻C.已知gloeosporioides Penz是苎麻炭疽病的病原体（2，3）。据我们所知，这是C.在中国和世界上引起苎麻炭疽病的Higginsianum。参考文献：（1）A. J. Caesar等人，Plant Dis.94：1166，2010（2）R. M. Li和H. G. MA. J. Plant Prot. 20：83，1993. (3)X. X. Wang等人，Plant Dis.94：1508，2010.
Ramie (Boehmeria nivea (L.) Gaud) anthracnose is regarded as one of the most widely spread and devastating diseases of ramie. This disease is most severe during warm and humid conditions. In China, ramie anthracnose is found in approximately 10,000 ha, with yield losses averaging 20% and ranging as high as 55% in some fields (3). In September 2010, typical anthracnose symptoms were observed in cultivated fields near Xianning, HuBei Province, China. Lesions on diseased leaves were initially small, scattered, bluish white, and water soaked. As the disease progressed, irregular spots developed on the leaves and the spots turned gray in the center with a brown margin. The diameter of the lesions was approximately 1 to 3 mm. Initially, lesions on the stems were fusiform and then expanded, causing the stem to break. Leaf and stem tissue adjacent to and including lesions were surface disinfected in 0.1% sodium hypochlorite and then planted on potato dextrose agar (PDA) plus oxalic acid to inhibit bacterial growth. The plates were incubated at 25°C for 3 to 5 days until the appearance of pink spore masses with numerous dense clusters of black setae. On PDA, the fungus initially produced gray colonies with an orange conidial mass and then the colonies turned black after 5 days. Spores were single celled, colorless, straight, oval, obtuse at both ends, 10.0 to 20.0 × 3.0 to 5.0 μm with an average size of 15.8 ± 2.4 × 4.6 ± 0.4 μm, and a length/width ratio of 3.47 ± 0.62. The setae were dark brown, 1 to 3 septa. These morphological traits corresponded to Colletotrichum higginsianum Sacc (1). The ITS1, 5.8S, and ITS2 sequences with primers ITS1 and ITS4 of this fungus (GenBank Accession No. JF830783) were 99% similar to sequences of multiple isolates of C. higginsianum (GenBank Accession Nos. GU935872 and AB042303). In pathogenicity tests, both sides of ramie plant leaves from 10-day-old, 30-cm high plants were sprayed with conidial suspensions (1 × 106 conidia/ml) of a representative fungal isolate. This experiment was repeated three times. Inoculated plants were incubated in an artificial climate chamber with a 12-h photoperiod at 25 to 28°C and a relative humidity of 90%. Three days after inoculation, brown spots and water-soaked lesions were observed on all inoculated leaves, but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by the reisolation of C. higginsianum from diseased leaves. C. higginsianum is known to cause anthracnose leaf spot disease on many cultivars of Brassica and Raphanus spp., but there have been no reports on it causing ramie anthracnose. C. boehmeriae Sawada and C. gloeosporioides Penz are known to be the agents of ramie anthracnose (2,3). To our knowledge, this is the first report of C. higginsianum causing anthracnose of ramie in China and in the world. References: (1) A. J. Caesar et al. Plant Dis. 94:1166, 2010 (2) R. M. Li and H. G. Ma. J. Plant Prot. 20:83, 1993. (3) X. X. Wang et al. Plant Dis. 94:1508, 2010.