Pazoutová S
Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic.
Folia Microbiol (Praha). 2009;54(3):217-29. doi: 10.1007/s12223-009-0035-4. Epub 2009 Aug 2.
Genetic variability of Phoma sorghina, a ubiquitous facultative phytopathogen, was investigated on 41 isolates cultivated from surface-sterilized sorghum grains originating from South Africa and Texas; pearl millet isolates from Namibia were also included. Most of the isolates from Texas produced intense red pigments, especially on Czapek-Dox agar plates. Many African isolates formed conspicuous dark radial substrate hyphae with intercalated chlamydospores on oatmeal plates. Conidial dimensions and shape were very variable (mean lengths 4.5-5.7 microm). Haplotypes were defined based on 53 markers from banding patterns obtained with rep-PCR (primers: M13core, ERIC IR). The shared geographic origin was partially reflected in the clades of the haplotype phylogram. The values of G(ST) were intermediate; 16-37 % of the variation was found between the populations. Nm values of gene flow were 0.84-1.15. Average gene diversity H(E) was moderate (0.256). Sequences of ITS-rDNA were obtained from 21 isolates. Allele 1 was found in 9 isolates scattered throughout the clades, allele 2 occurred in 6 isolates (5 of them from the same clade), alleles 3 and 4 were shared by two isolates each and two isolates were unique. Alleles 1 and 2 were also found among highly related sequences from GenBank. All shared an 8-bp deletion near the 5' end of ITS2 that was not found in any other Phoma/Didymella species and which may be a typical marker for P. sorghina. Among related species, members of legume-associated Ascochyta/Didymella complex, Epicoccum spp., D. applanata and P. glomerata were found.
对一种广泛存在的兼性植物病原菌——高粱茎点霉（Phoma sorghina）的遗传变异性进行了研究，研究对象包括从南非和得克萨斯州表面消毒的高粱籽粒中培养出的41个分离株；还纳入了来自纳米比亚的珍珠粟分离株。得克萨斯州的大多数分离株产生强烈的红色色素，尤其是在查氏琼脂平板上。许多非洲分离株在燕麦平板上形成明显的深色放射状基内菌丝，并带有间生厚垣孢子。分生孢子的尺寸和形状变化很大（平均长度4.5 - 5.7微米）。基于rep-PCR（引物：M13core、ERIC IR）获得的条带模式中的53个标记定义单倍型。单倍型系统发育树的分支部分反映了共同的地理起源。G(ST)值处于中等水平；种群间发现16 - 37%的变异。基因流的Nm值为0.84 - 1.15。平均基因多样性H(E)适中（0.256）。从21个分离株中获得了ITS-rDNA序列。等位基因1在分布于各个分支的9个分离株中发现，等位基因2出现在6个分离株中（其中5个来自同一分支），等位基因3和4各由两个分离株共享，还有两个分离株具有独特的等位基因。等位基因1和2也在来自GenBank的高度相关序列中发现。所有这些序列在ITS2的5'端附近都有一个8 bp的缺失，这在任何其他茎点霉属/双隔孢属物种中都未发现，可能是高粱茎点霉的一个典型标记。在相关物种中，发现了与豆科植物相关的壳二孢属/双隔孢属复合体、附球菌属（Epicoccum spp.）、平展双隔孢（D. applanata）和聚生茎点霉（P. glomerata）的成员。
