Molecular Identification Of Trichoderma Strains Collected To Develop Plant Growth-Promoting And Biocontrol Agents

Abstract

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.

Biochar-Rhizosphere Interactions – a Review

“…Microbial material consisted of the following strains: T. atroviride TRS7, T. atroviride TRS14, T. simmonsii TRS75, and T. virens TRS109 (Culture Collection of Microbiology Lab, Research Institute of Horticulture, Skierniewice). Molecular identification of these strains, based on sequences of ITS1 and ITS2, tef1alpha, rpb2 and chi18-5, was described in the previous work (Skoneczny et al, 2015;Oskiera et al, 2015). The tested strains were stored on PDA (Potato Dextrose Agar) slants at 4°C.…”

Towards the Biological Control of Devastating Forest Pathogens from the Genus Armillaria

“…Thermal cycling parameters were as follows; initial denaturation at 94 • C for 5 min, 35 cycles of DNA denaturation at 94 • C for 30 s, primer annealing at 50 • C for 30 s, elongation at 72 • C for 50 s, and a final elongation at 72 • C for 7 min. For amplification of the translation elongation factor 1-alpha (tef1α) gene fragment, reaction mixtures were the same as described above, but with universal primers TEF-LLErev (5 -AACTTGCAGGCAATGTGG-3 ) and EF1-728F: (5 -CATCGAGAAGTTCGAGAAGG-3 ) [20] and the thermal cycling program, with an initial denaturation at 94 • C for 5 min, 40 cycles of DNA denaturation at 94 • C for 45 s, primer annealing at 57 • C for 30 s, elongation at 72 • C for 90 s, and a final elongation at 72 • C for 7 min. The amplicon quality was detected by 2% agarose gel electrophoresis of 4 µL samples from the reaction mixtures.…”

Internal transcribed spacers (ITS) based identification of Trichoderma isolates and biocontrol activity against Macrophomina phaseolina, Aspergillus niger and Meloidogyne incognita

“…These results confirm the efficiency of barcode DNA and are compatible with previous studies that employed ITS to identify Trichoderma spp. (Wu et al, 2017;Fahmi et al, 2016;Savitha and Sriram, 2015;Oskiera et al, 2015).…”

“…It was reported that identification of Trichoderma based on morphological characters can give misleading results (Fahmi et al, 2016). Recently, molecular identification based on internal transcribed spacers (ITS) amplification and sequencing is common and highly trusted (Savitha and Sriam, 2015;Fahmi et al, 2016;Oskiera et al, 2015;Jiang et al, 2016).…”