Abstract
Background The phylogeny and phylogenetic relationships ofTrichodermaspecies were investigated by many methods including maximum parsimony and distance analysis of DNA sequences from multiple genetic loci.5.8S rDNAsequence analysis is a powerful tool in evolution studies. Main body The aim of this study was to identify and determine the genetic distance between 36Trichodermaisolates from Egyptian and Saudi Arabian soils based on their5.8S rDNAsequences. The genetic diversity ofTrichoderma(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, namelyT. longibarchiatum(42.7% of the isolates) andT. 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 includedT. lentiformeandT. crassumisolates, and the second subgroup harboredT. longibrachiatum,T. pseudokoningii, andT. bissettii. The second group includedT. neokoningiiandT. yunnanens. The cluster analysis of isolates from Saudi Arabia also consisted of two groups. The first group was subdivided into two subgroups; the first includedT.longibrachiatumandT. pseudokoningii. The second subgroup harboredT. simmonsiiandT. lentiforme. Also, no correlation between genetic and geographic distance was detected. Conclusion 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 assessingTrichodermagenetic diversity.