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Background: 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. Main body: 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. 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 assessing Trichoderma genetic diversity. [ABSTRACT FROM AUTHOR]

Accumulation of heavy metals (HMs) by ornamental plants (OPs) from contaminated agriculture soils is a unique technique that can efficiently reduce the metal load in the food chain. Amaranthus tricolor L. has attractive characteristics acquiring a higher growth rate and large biomass when grown at heavy metal contaminated soils. Site-specific detailed information is not available on the use of A. tricolor plant in metal phytoremediation from the polluted sites. The study aimed to enhance the uptake of HMs (Pb, Zn, and Cu) via amending poultry litter extract (PLE), vinasse sugarcane (VSC), and humic acid (HA) as natural mobilized organic materials compared to ethylene diamine tetraacetic acid (EDTA), as a common mobilized chemical agent by A. tricolor plant. The studied soils collected from Helwan, El-Gabal El-Asfar (Cairo Governorate), Arab El-Madabeg (Assiut Governorate), Egypt, and study have been conducted under pot condition. Our results revealed all organic materials in all studied soils, except EDTA in EL-Gabal El-Asfar soil, significantly increased the dry weight of the A. tricolor plant compared to the control treatment. The uptake of Pb and Zn significantly ( p > 0.05) increased due to applying all organic materials to the studied soils. HA application caused the highest uptake as shown in Pb concentration by more than 5 times in Helwan soil and EDTA by 65% in El-Gabal El-Asfar soil while VSC increased it by 110% in El-Madabeg soil. Also, an increase in Zn concentration due to EDTA application was 58, 42, and 56% for Helwan, El-Gabal El-Asfar, and El-Madabeg soil, respectively. In all studied soils, the application of organic materials increased the remediation factor (RF) than the control. El-Madabeg soil treated with vinasse sugarcane gave the highest RF values; 6.40, 3.26, and 4.02% for Pb, Zn, and Cu, respectively, than the control. Thus, we identified A. tricolor as a successful ornamental candidate that, along with organic mobilization amendments, most efficiently develop soil health, reduce metal toxicity, and recommend remediation of heavy metal-contaminated soils. Additionally, long-term application of organic mobilization amendments and continued growth of A . tricolor under field conditions could be recommended for future directions to confirm the results.