Phytopathology. 2003 Jan;93(1):64-70. doi: 10.1094/PHYTO.2003.93.1.64.
ABSTRACT Diversity in host range, pathogenicity, phenotypic characteristics, repetitive extragenic palindromic polymerase chain reaction (rep-PCR) profiles, and sequence of the 16S-23S rDNA spacer region was examined among 44 Xanthomonas strains isolated from lettuce. Forty-two of the strains were divided into two groups, designated A and B. Seventy percent were Group A, and most of the remaining strains including a reference strain (LMG 938) were Group B. Group A strains induced both local and systemic symptoms, whereas Group B strains caused only distinct necrotic spots. Two strains, including the X. campestris pv. vitians type strain, were distinct from the Group A and B strains and were not pathogenic on lettuce. Analysis of fatty acid profiles, serotype, carbon substrate utilization patterns, and protein fingerprints confirmed this grouping. The Group A and B strains also formed two unique clusters (I and II) by rep-PCR profiling that corresponded to the two groups. Direct sequencing of a PCR-amplified DNA fragment (680 bp) from the 16S-23S rDNA spacer region of four representative strains, however, did not differentiate these groups. Serology and rep-PCR fingerprinting can be used to diagnose and identify X. campestris pv. vitians strains, while the other analyses evaluated are useful for strain characterization.
摘要 对从生菜中分离得到的 44 株黄单胞菌进行了宿主范围、致病性、表型特征、重复外回文聚合酶链反应（rep-PCR）图谱和 16S-23S rDNA 间隔区序列多样性的研究。42 株菌分为 A 组和 B 组。70%为 A 组，其余大部分菌株（包括参考菌株 LMG 938）为 B 组。A 组菌株可引起局部和系统性症状，而 B 组菌株仅引起明显的坏死斑。包括 X. campestris pv. vitians 模式株在内的两种菌株与 A 组和 B 组菌株不同，对生菜没有致病性。脂肪酸图谱、血清型、碳源利用模式和蛋白质指纹图谱分析证实了这一分组。rep-PCR 图谱分析还表明，A 组和 B 组菌株形成了两个独特的聚类（I 和 II），与这两个组相对应。然而，对来自四个代表性菌株的 16S-23S rDNA 间隔区的 PCR 扩增 DNA 片段（680bp）进行直接测序并不能区分这些组。血清学和 rep-PCR 指纹图谱分析可用于诊断和鉴定 X. campestris pv. vitians 菌株，而其他评估的分析方法则可用于菌株特征描述。
