Characterization and Identification of Different Strains of Trichoderma Species using Biomolecular Techniques (original) (raw)
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Microorganisms
Trichoderma is the most commonly used fungal biocontrol agent throughout the world. In the present study, various Trichoderma isolates were isolated from different vegetable fields. In the isolated microflora, the colony edges varied from wavy to smooth. The mycelial forms were predominantly floccose with hyaline color and conidiophores among all the strains were highly branched. Based on morphological attributes, all the isolates were identified as Trichoderma harzianum. The molecular identification using multilocus sequencing ITS, rpb2 and tef1α, genes further confirmed the morphological identification. The average chitinase activity varied from 1.13 units/mL to 3.38 units/mL among the various isolates, which increased linearly with temperature from 15 to 30 °C. There was an amplified production in the chitinase production in the presence of Mg+ and Ca2+ and Na+ metal ions, but the presence of certain ions was found to cause the down-regulated chitinase activity, i.e., Zn2+, Hg2+,...
Trichoderma, soil-born filamentous fungi are capable of parasitizing several plant pathogenic fungi, it is known as biocontrol agents. Five isolates of Trichoderma spp. isolated from various crop rhizospheric soil in Uttar Pradesh districts were characterized by their cultural, morphological, and molecular level. The isolates differed significantly in terms of colony traits, sporulation, branching of conidiophores, and the colour and shape of phialospores. Molecular analysis of the isolates was done by sequencing the ITS region of ribosomal DNA using specific universal primers ITS 1 and ITS 4. Multiple nucleotide alignment of ITS 1, ITS 4 and 5.8s region depicted intra-specific and inter-specific variations in the ITS sequences among the different Trichoderma species. The result of this research obtained at morphological and ITS-based rDNA region sequencing. The sequencing of these five isolates revealed that the Trichoderma were characterized into Trichoderma lixii (Acc. No. OP031646), three Trichoderma harzianum (Acc. No. OP104445, OP104449, OP104451) and Trichoderma sp. (Acc. No. OP104454). However, significant percentage identity between the known isolate of T. lixii from the database and T. lixii (TBT-13) isolates from wheat is 97% whereas the percentage between the known isolate of T. harzianum and three species of T. harzianum (TBT-14, TBT-15, TBT-16) from potato, wheat, and mustard was 97-98% respectively. Similarly, Trichoderma spp. (TBT-17) are 98% identical to Trichoderma spp. result after NCBI-BLAST. As a result, the study was found to be helpful in identifying Trichoderma spp. from the rhizospheric soil of various crops.
Journal of Applied Biology & Biotechnology, 2020
In the present study, 20 fungal strains were isolated from tomato rhizosphere of Senegal. Of 20 strains, five showed the chitinolytic activity on chitin agar medium. Of the five strains, NG4 showed the maximum solubilization zone. This strain was identified by preliminary biochemical and 18S rRNA sequencing analysis. Enzyme production started after 3 days of incubation and maximum was observed after 5 days of incubation. Culture filtrate amended with 0.1% colloidal chitin was used in the production medium. The optimum conditions for maximum chitinase activity are-6 days of growth and temperature of 30°C at pH 6.0. The chitinase activity was also influenced by the addition of carbon and nitrogen sources in the production medium.
Trichoderma strains that are beneficial to both the growth and health of plants can be used as plant growth-promoting fungi (PGPF) or biological control agents (BCA) in agricultural and horticultural practices. In order to select PGPF or BCA strains, their biological properties and taxonomy must be carefully studied. In this study, 104 strains of Trichoderma collected at geographically different locations in Poland for selection as PGPF or BCA were identified by DNA barcoding, based on the sequences of internal transcribed spacers 1 and 2 (ITS1 and 2) of the ribosomal RNA gene cluster and on the sequences of translation elongation factor 1 alpha (tef1), chitinase 18-5 (chi18-5), and RNA polymerase II subunit (rpb2) gene fragments. Most of the strains were classified as: T. atroviride (38%), T. harzianum (21%), T. lentiforme (9%), T. virens (9%), and T. simmonsii (6%). Single strains belonging to T. atrobrunneum, T. citrinoviride, T. crassum, T. gamsii, T. hamatum, T. spirale, T. tomentosum, and T. viridescens were identified. Three strains that are potentially pathogenic to cultivated mushrooms belonging to T. pleuroticola and T. aggressivum f. europaeum were also identified. Four strains: TRS4, TRS29, TRS33, and TRS73 were classified to Trichoderma spp. and molecular identification was inconclusive at the species level. Phylogeny analysis showed that three of these strains TRS4, TRS29, and TRS33 belong to Trichoderma species that is not yet taxonomically established and strain TRS73 belongs to the T. harzianum complex, however, the species could not be identified with certainty.
Indian phytopathology, 2016
Trichoderma spp. are well described biocontrol fungi for its lytic activity and antagonistic properties against phytopathogens. The present studies were conducted to biochemically characterize Trichoderma spp. isolated from soils of Jammu. A total of fifty native isolates of Trichoderma spp. were screened on the basis of their antifungal activity using dual culture technique. Twenty promising isolates were evaluated for the secretion of extracellular hydrolytic enzymes viz . cellulases, chitinases and β-1, 3-glucanases. Enzyme activity detected in agar plates using their respective inducers as sole carbon sources and further tests for enzyme production in broth culture revealed that the majority of the isolates showed maximum specific enzyme activity up to 6 th day of incubation with few exceptions were FL322, OR26X and OR27 for cellulase; BR1, FL21 and CE32 for chitinase and 1CR2, AG20, FL41, FL322 and OR26X for glucanase which showed regular increasing trend up to 9 days. However,...
In vitro screening for enzymatic activity of Trichoderma species for biocontrol potential
A total of seven Trichoderma species were isolated from rhizosphere soils of brinjal on potato dextrose agar medium. Based on morphological and cultural characters, the isolates were assigned to different species viz., Trichoderma viride, T. harzianum, T. virens, T. atroviride, T. koningii, T. pseudokoningii and T. reesei. Trichoderma species were screened for the production of extracellular enzymes to identify the strain with high antagonistic potential against fungal pathogens. The screening was done following plate assay method on the respective solid media. These strains were positive for cellulase, amylase, pectinase, protease and chitinase activity. The excretion of extracellular lytic enzymes reveals their usefulness in the application of Trichoderma species as biocontrol strains in agricultural soils. The use of simple solid media permits the rapid screening of large populations of fungi for the presence or absence of specific enzymes
Turkish Journal of Biology, 2003
It is well known that Trichoderma spp. can be used as a biological control agent. In this study, Trichoderma isolates were obtained from 31 different Eskisehir soil samples. The biocontrol and antifungal effects of these isolates against various plant pathogen fungi were determined. We found that all filtrates of Trichoderma harzianum T9, T10, T15 and T19 were effective against plant pathogens Fusarium culmarum, F. oxysporum, F. moniliforme, Rhizoctonia solani, Sclerotium rolfsii, Gaeumannomyces graminis var. tritici and Drechslera sorokiniana. Among these isolates, T. harzianum T19 showed a wide range of inhibitory effects on plant pathogens. F. oxysporum was found to be the most resistant to the filtrates of the strains above. All isolates showed different behaviors depending on the physiological tests carried out such as growth in the presence inhibitory substrates, pH limits of growth and hydrolysis of gelatin. T. harzianum isolates were grown on the chitin, which is the sole carbon source. The chitinase activity determined from T. harzianum T15 by SDS-PAGE was nearly 73 kDa.