Seventeen species of Trichoderma, isolated from soil or tree bark from Ch ina are identified based on morphological and physiological characters, and from their phylogenetic position inferred from parsimony analyses o...Seventeen species of Trichoderma, isolated from soil or tree bark from Ch ina are identified based on morphological and physiological characters, and from their phylogenetic position inferred from parsimony analyses of nucleotide sequ ences of the internal transcribed spacer regions of the rDNA cluster (ITS1 and 2) and partial sequences of translation elongation factor 1-alpha (te f1) . There were T.citrinoviride, T.longibrachiatum, T.sinensis in section Long ibrachiatum, T.atroviride, T.koningii, T.viride, T.asperellum, T.hamatum, T.e rinaceum in section Trichoderma, T.harzianum (H.lixii), T.inhamatum, T. ve lutinum, T.cerinum, T.strictipile, T.spirale, T.virens, H.nigrovirens (Trichode r ma sp.) in section Pachybasium. Among them four species: T. asperellum, T .velutinum, T.cerinum, T. spirale were reported firstly in China. In addition, two suspected new taxa (Trichoderma spp.) in Trichoderma s ec tion were proposed: Trichoderma sp.1 (ZAUT261, 4, 4A, 15A, 2C), Trich od erma sp.2 (2B, 5, 7A, 7B, 9A). Trichoderma sp.1 was similar to T.h a matum , but the temperature optimum for mycelial growth was lower than that of T.hamatum and the species tended to form hemisphaerical pustule with rela tively larger conidia (average length 4.6 μm×2.8 μm). Trichoderma sp.2 was distinguished morphologically from related species T. strigosum, T. pub escens, T. erinaceum, T. hamatum and Trichoderma sp.1 in pustules on CM D without fertile or sterile conidiophore elongation and distinctive phialide sh ape, the conidiophore branches similar to T.koningii, but the conidia sim ilar to T. viride, subglobose, conspicuously tuberculate.展开更多
Sclerotinia sclerotiorum is an important pathogen to many crops and is especially damaging to rape in China. As a model plant Arabidopsis thaliana (Col0) was transformed by spraying Agrobacterium tumefacience with Tri...Sclerotinia sclerotiorum is an important pathogen to many crops and is especially damaging to rape in China. As a model plant Arabidopsis thaliana (Col0) was transformed by spraying Agrobacterium tumefacience with Trichoderma endochitinase gene ThEn-42 at initial bud stage. Eleven seedlings (corresponding to about 0.22 percent transformation) exhibited resistance to hygromycin. The DNA fragment unique to endochitinase (ThEn-42) was amplified by Arabidopsis leaf-PCR or genomic DNA PCR. Unfertile, dwarf and normal phenotypes appeared in the T1 generation. In addition, an enhanced resistance to S. sclerotiorum was observed. The mortality percentage (7.7% to 33.3%) in transgenic plants was significantly lower than in non-transgenic plants (86.7%) 10 days after inoculation with the pathogen.展开更多
Three strains of Trichoderma spp. TV112, TX003, TY009 obtained from previous experiments could inhibit the sclerotial formation of two strains of Rhizoctonia salani AG1 (-1A) isolated from the rice paddies in Hanzhou ...Three strains of Trichoderma spp. TV112, TX003, TY009 obtained from previous experiments could inhibit the sclerotial formation of two strains of Rhizoctonia salani AG1 (-1A) isolated from the rice paddies in Hanzhou of China. However, it is unclear if there are the antagonism and mycoparasitism of the Trichoderma strains tested against the mycelial growth of R. solani . The objective of this research was to evaluate the ability of the Trichoderma strains to inhibit the mycelial growth of R. solani in vitro . Dual culture testes showed all the Trichoderma strains tested inhibited the mycelial growth of R. solani. The strains also produced toxic metabolites with activity against R. solani, inhibiting the mycelial growth by 74%, 81.8%, and 53%, repectively. Electron microscopic observations revealed that all the Trichoderma strains interacted with R. solani . The strains TV112 and TX003 grew toward and coiled tightly around the host cells, penetrating and destroying the hyphae. TX009 penetrated the cell wall of R. solani by antagonist directly without formation of appressorium-like structure. Penetration of the Trichoderma strains on host cells was apparently accomplished by mechanical activity. These results demonstrated that all the three strains were effective in inhibiting the mycelial growth of R. solani .展开更多
文摘Seventeen species of Trichoderma, isolated from soil or tree bark from Ch ina are identified based on morphological and physiological characters, and from their phylogenetic position inferred from parsimony analyses of nucleotide sequ ences of the internal transcribed spacer regions of the rDNA cluster (ITS1 and 2) and partial sequences of translation elongation factor 1-alpha (te f1) . There were T.citrinoviride, T.longibrachiatum, T.sinensis in section Long ibrachiatum, T.atroviride, T.koningii, T.viride, T.asperellum, T.hamatum, T.e rinaceum in section Trichoderma, T.harzianum (H.lixii), T.inhamatum, T. ve lutinum, T.cerinum, T.strictipile, T.spirale, T.virens, H.nigrovirens (Trichode r ma sp.) in section Pachybasium. Among them four species: T. asperellum, T .velutinum, T.cerinum, T. spirale were reported firstly in China. In addition, two suspected new taxa (Trichoderma spp.) in Trichoderma s ec tion were proposed: Trichoderma sp.1 (ZAUT261, 4, 4A, 15A, 2C), Trich od erma sp.2 (2B, 5, 7A, 7B, 9A). Trichoderma sp.1 was similar to T.h a matum , but the temperature optimum for mycelial growth was lower than that of T.hamatum and the species tended to form hemisphaerical pustule with rela tively larger conidia (average length 4.6 μm×2.8 μm). Trichoderma sp.2 was distinguished morphologically from related species T. strigosum, T. pub escens, T. erinaceum, T. hamatum and Trichoderma sp.1 in pustules on CM D without fertile or sterile conidiophore elongation and distinctive phialide sh ape, the conidiophore branches similar to T.koningii, but the conidia sim ilar to T. viride, subglobose, conspicuously tuberculate.
文摘Sclerotinia sclerotiorum is an important pathogen to many crops and is especially damaging to rape in China. As a model plant Arabidopsis thaliana (Col0) was transformed by spraying Agrobacterium tumefacience with Trichoderma endochitinase gene ThEn-42 at initial bud stage. Eleven seedlings (corresponding to about 0.22 percent transformation) exhibited resistance to hygromycin. The DNA fragment unique to endochitinase (ThEn-42) was amplified by Arabidopsis leaf-PCR or genomic DNA PCR. Unfertile, dwarf and normal phenotypes appeared in the T1 generation. In addition, an enhanced resistance to S. sclerotiorum was observed. The mortality percentage (7.7% to 33.3%) in transgenic plants was significantly lower than in non-transgenic plants (86.7%) 10 days after inoculation with the pathogen.
文摘Three strains of Trichoderma spp. TV112, TX003, TY009 obtained from previous experiments could inhibit the sclerotial formation of two strains of Rhizoctonia salani AG1 (-1A) isolated from the rice paddies in Hanzhou of China. However, it is unclear if there are the antagonism and mycoparasitism of the Trichoderma strains tested against the mycelial growth of R. solani . The objective of this research was to evaluate the ability of the Trichoderma strains to inhibit the mycelial growth of R. solani in vitro . Dual culture testes showed all the Trichoderma strains tested inhibited the mycelial growth of R. solani. The strains also produced toxic metabolites with activity against R. solani, inhibiting the mycelial growth by 74%, 81.8%, and 53%, repectively. Electron microscopic observations revealed that all the Trichoderma strains interacted with R. solani . The strains TV112 and TX003 grew toward and coiled tightly around the host cells, penetrating and destroying the hyphae. TX009 penetrated the cell wall of R. solani by antagonist directly without formation of appressorium-like structure. Penetration of the Trichoderma strains on host cells was apparently accomplished by mechanical activity. These results demonstrated that all the three strains were effective in inhibiting the mycelial growth of R. solani .
