Identification and characterisation of Xanthomonas campestris pv. campestris strains from Tanzania by pathogenicity tests, Biolog, rep-PCR and fatty acid methyl ester analysis
Identification and characterisation of Xanthomonas campestris pv. campestris strains from Tanzania by pathogenicity tests, Biolog, rep-PCR and fatty acid methyl ester analysis
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DOI：
10.1023/a:1026194402701
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发表时间：
2003-10-01
影响因子：
1.8
通讯作者：
Mortensen, CN
中科院分区：
文献类型：
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作者：
Massomo, SMS;Nielsen, H;Mortensen, CN
由油菜黄单胞菌引起的黑腐病。白菜病是制约非洲小农白菜生产的主要病害。病原体内部存在变异性，但Xcc菌株与其他密切相关的攻击十字花科植物的黄原菌通常很难区分。采用生物系统、微生物鉴定系统（MIS）脂肪酸甲酯分析、rep-PCR和致病性试验对坦桑尼亚Xcc菌株进行鉴定和鉴定。Xcc菌株在生物学图谱和rep-PCR图谱上具有很大的多样性。特异的rep-PCR基因组指纹图谱与该国的一些地理区域相关联。根据其在白菜中的脂肪酸谱和症状表达情况，大多数Xcc菌株可归为两类，但也发现了一些异常菌株。每种方法都可以在一定程度上从种、病原到菌株水平进行鉴定。生物学和MIS鉴定出所有Xcc菌株至少达到属水平。此外，生物学鉴定出47%的Xcc菌株具有致病变异，43%的菌株具有菌株水平，而MIS鉴定出43%的菌株具有致病变异水平。在缺乏数据库的情况下，尽管该程序可以很好地将Xcc描述到菌株水平，但rep-PCR在常规菌株诊断中的应用受到限制。这些发现表明坦桑尼亚存在的Xcc菌株与生物学和MIS数据库中包含的菌株不同。注意到的局限性需要继续改进数据库和纳入致病性测试，使用普遍敏感的品种，作为菌株鉴定的组成部分。
Black rot, caused by Xanthomonas campestris pv. campestris (Xcc), is a major disease constraint to cabbage production by smallholder farmers in Africa. Variability exists within the pathogen, and yet differentiation of Xcc strains from other closely-related xanthomonads attacking crucifers is often difficult. The Biolog system, fatty acid methyl ester analysis using microbial identification system (MIS), rep-PCR and pathogenicity tests were used to identify and characterise Xcc strains from Tanzania. Great diversity was observed among Xcc strains in their Biolog and rep-PCR profiles. Specific rep-PCR genomic fingerprints were linked to some geographical areas in the country. Most of the Xcc strains were clustered in two groups based on their fatty acid profiles and symptom expression in cabbage although some deviant strains were found. Each of the methods allowed a degree of identification from species, pathovar to the strain level. Biolog and MIS identified all Xcc strains at least to the genus level. Additionally, Biolog identified 47% of Xcc strains to the pathovar and 43% to strain level, whereas MIS identified 43% of the strains to pathovar level. In the absence of a database, the utility of rep-PCR for routine diagnosis of strains was limited, although the procedure was good for delineation of Xcc to the strain level. These findings indicate the existence of Xcc strains in Tanzania that are distinct from those included in Biolog and MIS databases. The limitations noticed warrant continued improvement of databases and inclusion of pathogenicity testing, using universally susceptible cultivars, as an integral part of strain identification.