With increased imports of foreign microbes either as commercial biocontrol produ cts or for the purposes of research, there is potentially an increased threat to indigenous beneficial microflora. In the present study,...With increased imports of foreign microbes either as commercial biocontrol produ cts or for the purposes of research, there is potentially an increased threat to indigenous beneficial microflora. In the present study, indigenous species of t he fungal genus Hypocrea/Trichoderma are being used as a model system to d etermine the impact of foreign microbes on the native microflora of New Zealand. In order to protect such microflora, one has to first be aware of what is curre ntly present and what sites, if any, are most vulnerable. A preliminary survey f or the presence and diversity of species of Hypocrea/Trichoderma is curren tly underway in New Zealand and samples are being assessed from forest soils, ag ricultural soils, orchards, garden soils, sclerotia of various plant pathogens a nd pasture land. To date 238 isolates have been identified using both morphologi cal characters and DNA sequence data from the ITS regions of the ribosomal gene cluster (ITS1 & ITS2) and, in some instances, sequence of the elongation facto r gene (EF1-α) . Isolates were found to represent 16 known species plus three s pec ies as yet undescribed. In forest soils T. harzianum /T. inhamatum (31%) and T. viride (29%) followed by T. fertile (13%), were clearly th e most abundant species and the remaining five species found in forests (T. a troviride, T. koningii, T. aureoviride, H. cf. flavovirens anamorph and one u nknown) each accounting for <8% of the total. Dominance by the species T. h arzianum/inhamatum is consistent with studies done in South-East Asia, a mid -E uropean primeval floodplain-forest and Moscow. In contrast, when isolations wer e conducted with a bias for biocontrol capabilities it was found that the species T. atroviride (29%), T. koningii (17 %), T. harzianum (1 5%) and T. viride (12%) dominated respectively. This survey is currently on go ing in New Zealand. Future studies will monitor indigenous species and strains f ollowing inoculation of specific microbes to assess the impact of the introduced microbe on the natural ecosystem.展开更多
文摘With increased imports of foreign microbes either as commercial biocontrol produ cts or for the purposes of research, there is potentially an increased threat to indigenous beneficial microflora. In the present study, indigenous species of t he fungal genus Hypocrea/Trichoderma are being used as a model system to d etermine the impact of foreign microbes on the native microflora of New Zealand. In order to protect such microflora, one has to first be aware of what is curre ntly present and what sites, if any, are most vulnerable. A preliminary survey f or the presence and diversity of species of Hypocrea/Trichoderma is curren tly underway in New Zealand and samples are being assessed from forest soils, ag ricultural soils, orchards, garden soils, sclerotia of various plant pathogens a nd pasture land. To date 238 isolates have been identified using both morphologi cal characters and DNA sequence data from the ITS regions of the ribosomal gene cluster (ITS1 & ITS2) and, in some instances, sequence of the elongation facto r gene (EF1-α) . Isolates were found to represent 16 known species plus three s pec ies as yet undescribed. In forest soils T. harzianum /T. inhamatum (31%) and T. viride (29%) followed by T. fertile (13%), were clearly th e most abundant species and the remaining five species found in forests (T. a troviride, T. koningii, T. aureoviride, H. cf. flavovirens anamorph and one u nknown) each accounting for <8% of the total. Dominance by the species T. h arzianum/inhamatum is consistent with studies done in South-East Asia, a mid -E uropean primeval floodplain-forest and Moscow. In contrast, when isolations wer e conducted with a bias for biocontrol capabilities it was found that the species T. atroviride (29%), T. koningii (17 %), T. harzianum (1 5%) and T. viride (12%) dominated respectively. This survey is currently on go ing in New Zealand. Future studies will monitor indigenous species and strains f ollowing inoculation of specific microbes to assess the impact of the introduced microbe on the natural ecosystem.
