Molecular identification of Colletotrichum gloeosporioides causing yam anthracnose in Nigeria
Molecular identification of Colletotrichum gloeosporioides causing yam anthracnose in Nigeria
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DOI：
10.1046/j.0032-0862.2001.00655.x
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发表时间：
2002-02-01
期刊：
影响因子：
2.7
通讯作者：
Wolf, GA
中科院分区：
文献类型：
--
作者：
Abang, MM;Winter, S;Wolf, GA
在尼日利亚发现了与山药叶炭疽病相关的代表三种不同毒力表型的四种形式的炭疽菌：高毒力（=疾病的严重程度）缓慢生长的灰（SGG）;中等毒力快速生长的鲑鱼（FGS）;弱毒力快速生长的灰（FGG）;和中等毒力快速生长的橄榄（FGO）形态型。这四种形式的分离物被鉴定为C. gloeosporioides的形态学特征。采用单分生孢子培养物在酪蛋白水解培养基（CHM）上的反应、PCR-RFLP和核糖体DNA内转录间隔区（ITS 1 -5- 8 S-ITS 2）序列分析等方法对山药炭疽病病原菌进行了鉴定。所有的山药分离物都与C. acutatum的蛋白酶活性的情况下，CHM。经ITS PCR和酶切鉴定，FGS、FGO和SGG分离物的RFLP图谱均与C. Gloeosporioides参考菌株，而FGG菌株显示独特的ITS RFLP带型。ITS 1区和整个ITS区的序列分析表明，SGG、FGS和FGO分离物高度相似（98-99%核苷酸同一性），与C.胶孢菌这些真菌分离物与参考C. acutatum和C.观察到林德木硫菌分离物。分子生物学研究证实了山药炭疽病是由C.胶孢菌而大多数C. Gloeosporioides真菌从山药，分离物的FGG形式没有集群与任何先前描述的炭疽菌属物种，并可能代表一个独特的物种。
Four forms of Colletotrichum representing three distinct virulence phenotypes were found associated with foliar anthracnose of yam in Nigeria: the highly virulent (= severity of disease) slow-growing grey (SGG); the moderately virulent fast-growing salmon (FGS); the weakly virulent fast-growing grey (FGG); and the moderately virulent fast-growing olive (FGO) morphorype. Isolates of the four forms were identified as C. gloeosporioides, based on morphology. The reaction of monoconidial cultures on casein hydrolysis medium (CHM), PCR-RFLP and sequence analysis of the internal transcribed spacer region of the ribosomal DNA (ITS1-5-8S-ITS2) were used to establish the identity of the yam anthracnose pathogen(s). All yam isolates were distinguished from C. acutatum by the absence of protease activity on CHM. On ITS PCR and enzymatic digestion of PCR products, all FGS, FGO and SGG isolates produced RFLP patterns identical to those of C. gloeosporioides reference isolates, while FGG isolates revealed unique ITS RFLP banding patterns. Sequence analysis of the ITS1 region and of the entire ITS region revealed that SGG, FGS and FGO isolates were highly similar (98-99% nucleotide identity) and showed 97-100% identity to C. gloeosporioides. Less than 93% similarity of these fungal isolates to reference C. acutatum and C. lindemuthianum isolates was observed. The molecular study confirmed that foliar anthracnose of yam is caused by C. gloeosporioides. While a high similarity was found among most C. gloeosporioides fungi from yam, isolates of the FGG form did not cluster with any previously described Colletotrichum species, and probably represent a distinct species.