NUCLEOTIDE DIVERSITY AMONG TRICHODERMA SPP. COLLECTED FROM DIFFERENT LOCATIONSAND DETECTION OF WITHIN-SPECIES DIVERSITYMOHAMED F. AWAD AND MOHAMED ISMAILAbstract The diversity of Trichoderma (Hypocreales, Ascomycota) species from Egypt and Saudi Arabia was achieved, and DNA barcoding of 21 strains based on the internal transcribed spacers 1 and 4 (ITS1 and 4) of the ribosomal RNA gene cluster and the partial sequence of the ITS1 and ITS4 gene revealed that the diversity of Trichoderma according to molecular findings there were two main species predominated in these isolates. T. harzianum consisted about 33.4 % of the isolates and T. longibarchiatum consisted about 19.1% of the isolates. Consequently, variation among individuals of the same species was noticed. For the GC% in T. viride was 55%, in Egyptian isolates. Also, within Saudi Arabia isolates, the T. longibrachiatum varied in GC% was between 56% and 57%. Cluster analysis of the Egyptian isolates showed two groups, the first group subdivided into two subgroups. The first subgroup included T. harzianum isolates, the second sub group harboured T. virdie and T. longibrachiatum. The second group included T. asperellum, and T. koninigigiopsis. Also, the cluster analysis of Saudi Arabia isolates showed two groups. The first group subdivided into two subgroups; the first subgroup included T. harzianum, H. lixii, T. longibrachiatum and H. koningii. The second subgroup harboured T. atrovirdie, T. saturnisporum and H. koningii. The Saudi Arabia isolates showed higher nucleotide diversity compared to its Egyptian counterpart. Number of haplotypes identified in Saudi Arabia isolates was two-fold higher than that of Egyptian isolates. |