Trichoderma asperellum: First report in Bangladesh

The experiment was conducted at four laboratory, Bangladesh Agricultural University, Mymensingh to identify T. asperellum and its characterization was obtained from the rhizosphere of 49 different crops in 109 different locations of 36 districts in Bangladesh. Fifteen isolates of 88 isolates in T. asperellum were characterized on morphological and physiological features. All of the isolates were produced at 35 °C, but only TR27 and TR45 were grown and sporulate at 40 °C. Mycelial growth of all the isolates was reduced with the increasing of pH value. Molecular characterization in four isolates of TR27, TR45, TR70 and TR85 were studied at ITS and TEF region nucleotide sequencing among 15 isolates of T. asperellum and the morphological characterization at ITS and tef1 nucleotide sequencing was assimilated with molecular characterization. The isolates of TR45, TR70 and TR85 were found with 98% homology and TR27 exhibited 88% against their respective closest isolate. The isolates of TR27 and TR85 marked their respective nearest homology at 96%, while TR45 showed 99%, and 93% homology was signified with TR70 in TEF sequences. Three isolates (TR45, TR70 and TR85) were identified as T. asperellum of 100% bootstrap value and TR27 isolate was also recognized with 72% bootstrap value in phylogenetic tree. In phylogenetic analysis, tef1 extended better differentiation among the Trichoderma isolates within and among the groups of closely related species than the rDNA of the ITS region in reflecting wider variability in the isolates while a higher transversion ratio and evolutionary divergence were defined. Moreover the exploring of scientific and useful diversification of Trichoderma isolates on physiological and molecular traits has deemed in research fields. IMPORTANCE Trichoderma is an important genus in different aspect of uses as biofertilizer and bioremediation in agriculture. Specific identification in physiological and molecular characterization has also foremost attention with genome sequences as stored in databases. The diversity and genetic distances were ascertained among the isolates in phylogenetic analysis with the sequence data of the ITS region and tef1 of known Trichoderma strains was found in GenBank. Consequently, the databases of Trichoderma asperellum in molecular characterization can be frequently studied in the beneficial scope of agriculture. Trichoderma isolates of Rhizosphere soil in 4 locations with crops of (TR27) Sadar, Moulvibazar (Rice), (TR45) Sadar, Mymensingh (Sweet gourd), (TR70) Chapra, Chapai Nawabganj (Sesame) and (TR85) Nayanpur, Lalmonirhat (Maize) were found to be substantiated as Trichoderma asperellum strain in Bangladesh that were confirmed on physiological and molecular characters, and utilization of this strain can run faster in invasive technologies to control crop diseases.