The phylogeny and phylogenetic relationships of Trichoderma species were investigated by many methods including maximum parsimony and distance analysis of DNA sequences from multiple genetic loci. 5.8S rDNA sequence analysis is a powerful tool in evolution studies. The aim of this study was to identify and determine the genetic distance between 36 Trichoderma isolates from Egyptian and Saudi Arabian soils based on their 5.8S rDNA sequences. The genetic diversity of Trichoderma (Hypocreales, Ascomycota) species from Egypt and Saudi Arabia was investigated. The DNA barcoding of 36 isolates, based on the internal transcribed spacers 1 and 4 (ITS1 and 4) of the ribosomal RNA gene cluster and the partial sequence of this gene, revealed the diversity of these isolates. BLAST query showed that two species, namely T. longibarchiatum (42.7% of the isolates) and T. lentiforme (33.3% of the isolates), pre-dominated the isolates. Variation among specimens of the same species was detected. Cluster analysis of the Egyptian isolates showed two groups; the first group was subdivided into two subgroups, the first of which included T. lentiforme and T. crassum isolates, and the second subgroup harbored T. longibrachiatum, T. pseudokoningii, and T. bissettii. The second group included T. neokoningii and T. yunnanens. The cluster analysis of isolates from Saudi Arabia also consisted of two groups. The first group was subdivided into two subgroups; the first included T. longibrachiatum and T. pseudokoningii. The second subgroup harbored T. simmonsii and T. lentiforme. Also, no correlation between genetic and geographic distance was detected. The results of the present study indicated that the Saudi Arabian isolates showed greater nucleotide diversity compared to Egyptian isolates. Also, these findings will assist in future studies while assessing Trichoderma genetic diversity.

中文翻译：

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木霉属之间的比较分子遗传多样性。来自埃及和沙特阿拉伯

通过多种方法研究了木霉属种的系统发生和系统发生关系，包括最大简约性和距离多个遗传基因座的DNA序列的距离分析。5.8S rDNA序列分析是进化研究中的强大工具。这项研究的目的是基于5.8S rDNA序列，鉴定和确定36种埃及和沙特阿拉伯土壤木霉分离株之间的遗传距离。研究了来自埃及和沙特阿拉伯的木霉属（Hypocreales，Ascomycota）的遗传多样性。基于核糖体RNA基因簇的内部转录间隔区1和4（ITS1和4）以及该基因的部分序列，对36个分离株的DNA条形码显示了这些分离株的多样性。BLAST查询显示有两个物种，即长木丁香（42。7％的分离株）和T. lentiforme（33.3％的分离株）占主导地位。检测到相同物种的标本之间存在差异。埃及分离株的聚类分析显示两组。第一组分为两个亚组，第一组包括T. lentiforme和T. crassum分离株，第二组包含T. longibrachiatum，T。pseudokoningii和T. bissettii。第二组包括T. neokoningii和T. yunnanens。来自沙特阿拉伯的分离株的聚类分析也包括两组。第一组分为两个子组；第一个包括T. longibrachiatum和T. pseudokoningii。第二个亚群则藏有西蒙氏锥虫和慢形锥虫。另外，未检测到遗传距离与地理距离之间的相关性。本研究的结果表明，与埃及分离株相比，沙特阿拉伯分离株显示出更大的核苷酸多样性。同样，这些发现将有助于未来研究，同时评估木霉属的遗传多样性。