Trichoderma spp. is a filamentous soil fungus known as an effective biocontrol agent of a range of important airborne and soilborne pathogens, it has universal distribution and economic importance. This article review...Trichoderma spp. is a filamentous soil fungus known as an effective biocontrol agent of a range of important airborne and soilborne pathogens, it has universal distribution and economic importance. This article reviewed the researches on biocontrol mechanism for plant diseases and application of Trichoderma spp., especially Trichoderma harzianum in recent years展开更多
Different from ribosomal genes, which contain highly conserved sequences that are detected in all organisms, the intergenic spacer of rDNA (IGS) appears to be the most rapidly-evolving spacer region. For this reason w...Different from ribosomal genes, which contain highly conserved sequences that are detected in all organisms, the intergenic spacer of rDNA (IGS) appears to be the most rapidly-evolving spacer region. For this reason we tested this region for phylogenetic studies. This report focuses on the study of IGS sequences of isolates belonging to Trichoderma section (T. viride, T. koningii, T. hamatum, T. erinaceus, T. asperellum) and Pachybasium section (T. harzianum, T. crassum, T. fasciculatum, T. oblongisporum, T. virens). Using the primer pair 28STD and CNS1, the Fast Start Taq DNA Polymerase (Roche), and a three temperature PCR protocol, products ranging from ca 1900 to 2400 bp were obtained from all tested isolates. The PCR product of 16 Trichoderma spp. isolates was cloned into a pGEM-TEeasy Vector (Promega) and sequenced. Based on a BLAST search we can conclude that the PCR product represents the whole IGS region. Multiple alignments of IGS sequences revealed two portions with different homology level. Portion A (ca 1660 bp) is the portion that contains 3’ end of 28S gene and is the more variable, while portion B (ca 830 bp), that contains the 3’ end of IGS region and the 5’ end of 18S gene, is the less variable. Comparing all sequences in region A 705 identical pairs occur out of 1704 total nucleotides (41.4%), while in region B identical pairs were 723 out of 832 total nucleotides (86.9%) . Sequence comparison of the two regions at intraspecific level (where it was possible) showed higher variability in region A (0.17%-6.8%) than in region B (0.0%-1.0%) . At interspecific level, performing all possible comparisons, the variability of region A (19.5%-52.7%) and B (0.8%- 16.9%). were significantly higher. Comparing sequences of species belonging to Trichoderma section variability of the two regions appears reduced if compared with that obtained from comparisons of species belonging to Pachybasium section. On the basis of sequence alignment, phylogenetic trees were obtained either with entire IGS, with region A, and with region B. Results of this analysis revealed that all isolates belonging to Trichoderma section grouped separately from isolates belonging to Pachybasium section. IGS region allowed us to group species according to their taxonomic position. The topology of the tree did not change substantially, varying in genetic distance only. Performing a GenBank search sequences representing the final portion of the IGS region of other fungal species were found, and we carried out a multiple alignment using also our sequences of Trichoderma spp. and Diaporthe helianthi. The phylogeny inferred from sequence alignment matched the generally accepted morphology-based classification and was identical to other molecular schemes at high taxonomic level. Data analysis was useful in establishing a broad-scale phylogeny of Ascomycota and was also useful in sorting them into statistically-supported clades. The tree showed that Trichoderma occurred in a well-supported terminal subclade of a larger clade that also contained other genera belonging to Hypocreales order. Sequence analysis of the Trichoderma spp. IGS region allowed us to design a specific PCR primer that was successfully used to amplify region A. The new reverse primer LCR2, that recognize all Trichoderma isolates, was identified in region B and confirmed for its specificity on the DNA of fungi belonging to other Ascomycota genera. Results obtained showed that IGS region seems to be an interesting and versatile tool for phylogenetic analysis, for resolving some taxonomic problems and for constructing specific primer useful for different purposes.展开更多
The soil is a complex system where processes have direct influence on crop nutrition and plant health. Unfortunately, most of the agricultural soil management practices, compact them producing poor oxygenation, low be...The soil is a complex system where processes have direct influence on crop nutrition and plant health. Unfortunately, most of the agricultural soil management practices, compact them producing poor oxygenation, low benefic microorganism populations and metabolic disorders in plants. Those factors induce abnormal plant development and predisposition to the attack of soil borne plant pathogens as: Sclerotium cepivorum, Sclerotium rolfsi, Sclerotinia sclerotiorum, Rhizoctonia solani, Rosellinia spp. But also, some air borne pathogens as Colletotrichum sp., are more aggressive under those conditions. In Costa Rica some practical trails done by farmers, have shown that the addition of Trichoderma spp. to organic fertilizers like vermicompost, Bocashi, and other composts, has a positive effect on the structure and microbial diversity, that improves nutrient movement in plants and pathogen suppression. Vegetative material of leather fern (Rumohra adiantiformis) infected by Rosellinia spp., planted with bocashi amended with. T. asperellum (T. harzianum), showed more tip root growth and new fern rhizomes. Also the plants produced higher number of fiddleheads and high quality fronds. Non-treated material showed a total loss. In some leaf vegetables as lettuce the use of vermicompost followed by Trichoderma viride application, inhibited S. sclerotiorum development on the crop, in this study sclerotia were infected and plant yields were increased. Compost previously inoculated with Trichoderma, inhibited 100% the Botrytis and R. solani infection, in nurseries, and plant nutrition was improved. The observed results are attributed to the antagonistic effect of Trichoderma on soil and airborne pathogens, production of growth regulators, solubilization of some microelements and better mineral absorption with the development of more roots and elimination of diseased roots. As conclusion, the organic substrates inoculated with Trichoderma spp., besides the organic matter source, they improve the structural characteristics of soil, promote the biochemical processes, increases the level of growth regulator substances and inhibit plant disease as well.展开更多
A series of highly taxonomically diverse Trichoderma strains were investigated using proteomic approaches, to investigate the utility of protein profiles as taxonomic markers and to identify proteins of potential econ...A series of highly taxonomically diverse Trichoderma strains were investigated using proteomic approaches, to investigate the utility of protein profiles as taxonomic markers and to identify proteins of potential economic importance. Initial studies have focused on a comparison of single strains of T. aureoviride, T. saturnisporum, T. polysporum, T. longbrachiatum and T. spirale, along with two strains of T. harzianum. All seven strains were grown in synthetic medium supplemented with 2%(w/v) glycerol, to maximize the diversity of extracellular protein production. Samples of secreted protein were separated by 2D gel electrophoresis and will be characterized by MALDI-TOF peptide fingerprinting.展开更多
From over 800 fungal strains of Tri-choderma Spp. , 6 strains were foundto greatly inhibit the growing of Rhi-zocotonia solani, the pathogen of ricesheath blight in dual culture. Amongthem, strain T3 was the best anta...From over 800 fungal strains of Tri-choderma Spp. , 6 strains were foundto greatly inhibit the growing of Rhi-zocotonia solani, the pathogen of ricesheath blight in dual culture. Amongthem, strain T3 was the best antago-nist, which reduced the growing ofthe pathogen by 52.54% (Table 1).展开更多
Two different species, Trichoderma viride TV10 and Trichoderma harzianum TH12 from 30 Trichoderma isolates were selected out based on their high growth inhibition of the phytopathogen Sclerotinia sclerotiorum (Lib) de...Two different species, Trichoderma viride TV10 and Trichoderma harzianum TH12 from 30 Trichoderma isolates were selected out based on their high growth inhibition of the phytopathogen Sclerotinia sclerotiorum (Lib) de Bary, which reached 84.44% and 100%, respectively. Their untreated culture filtrates (CF) and culture filtrates treated with heat (CFH) also were tested for growth inhibition of the pathogen in potato dextrose agar (PDA). Morphological and molecular characterisation by internal transcribed spacer (ITS) PCR provided consistent identification of these isolates. The degree of infection and disease index (DI) of S. sclerotiorum were examined in Brassica napus (AACC) and Raphanus alboglabra (RR) and Brassica alboglabra (CC). The results revealed that Raphanus alboglabra showed higher disease resistance than that of B. napus. Biotic elecitors T. harzianum TH12 and T. viride TV10 and their CF and CFH demonstrated the ability to cause induced systemic resistance (ISR) in B. napus and Raphanus alboglabra against sclerotinia stem rot (SSR) disease. Furthermore, a high ability to reduce the degree of infection and DI in B. napus with the biotic elicitors T. harzianum TH12 and T. viride TV10 was observed, with numbers reaching 7.22% to 6.67% and 17.78% to 11.67%, respectively. When CF were used, reached 20.00% to 16.67% and 33.33% to 23.33%, respectively;with CFH, values reached 35.00% to 21.67% and 37.78% to 28.33%, respectively. While in Raphanus alboglabra the degree of infection and DI reached 0.00% and 0.00% with all biotic elicitors treatments. These results show that biotic elicitor treatments significantly (P B. napus and Raphanus alboglabra ranked as most effective. This study showed for the first time the ability of genotype Raphanus alboglabra (RRCC) to demonstrate resistance against S. sclerotiorum with or without treatment by biotic elicitors and the ability of genotype B. napus (AACC) to demonstrate resistance to the pathogen after treatment with biotic elicitors.展开更多
基金Supported by Chinese National Programs for High Technology Research and Development(2003AA241140)
文摘Trichoderma spp. is a filamentous soil fungus known as an effective biocontrol agent of a range of important airborne and soilborne pathogens, it has universal distribution and economic importance. This article reviewed the researches on biocontrol mechanism for plant diseases and application of Trichoderma spp., especially Trichoderma harzianum in recent years
文摘Different from ribosomal genes, which contain highly conserved sequences that are detected in all organisms, the intergenic spacer of rDNA (IGS) appears to be the most rapidly-evolving spacer region. For this reason we tested this region for phylogenetic studies. This report focuses on the study of IGS sequences of isolates belonging to Trichoderma section (T. viride, T. koningii, T. hamatum, T. erinaceus, T. asperellum) and Pachybasium section (T. harzianum, T. crassum, T. fasciculatum, T. oblongisporum, T. virens). Using the primer pair 28STD and CNS1, the Fast Start Taq DNA Polymerase (Roche), and a three temperature PCR protocol, products ranging from ca 1900 to 2400 bp were obtained from all tested isolates. The PCR product of 16 Trichoderma spp. isolates was cloned into a pGEM-TEeasy Vector (Promega) and sequenced. Based on a BLAST search we can conclude that the PCR product represents the whole IGS region. Multiple alignments of IGS sequences revealed two portions with different homology level. Portion A (ca 1660 bp) is the portion that contains 3’ end of 28S gene and is the more variable, while portion B (ca 830 bp), that contains the 3’ end of IGS region and the 5’ end of 18S gene, is the less variable. Comparing all sequences in region A 705 identical pairs occur out of 1704 total nucleotides (41.4%), while in region B identical pairs were 723 out of 832 total nucleotides (86.9%) . Sequence comparison of the two regions at intraspecific level (where it was possible) showed higher variability in region A (0.17%-6.8%) than in region B (0.0%-1.0%) . At interspecific level, performing all possible comparisons, the variability of region A (19.5%-52.7%) and B (0.8%- 16.9%). were significantly higher. Comparing sequences of species belonging to Trichoderma section variability of the two regions appears reduced if compared with that obtained from comparisons of species belonging to Pachybasium section. On the basis of sequence alignment, phylogenetic trees were obtained either with entire IGS, with region A, and with region B. Results of this analysis revealed that all isolates belonging to Trichoderma section grouped separately from isolates belonging to Pachybasium section. IGS region allowed us to group species according to their taxonomic position. The topology of the tree did not change substantially, varying in genetic distance only. Performing a GenBank search sequences representing the final portion of the IGS region of other fungal species were found, and we carried out a multiple alignment using also our sequences of Trichoderma spp. and Diaporthe helianthi. The phylogeny inferred from sequence alignment matched the generally accepted morphology-based classification and was identical to other molecular schemes at high taxonomic level. Data analysis was useful in establishing a broad-scale phylogeny of Ascomycota and was also useful in sorting them into statistically-supported clades. The tree showed that Trichoderma occurred in a well-supported terminal subclade of a larger clade that also contained other genera belonging to Hypocreales order. Sequence analysis of the Trichoderma spp. IGS region allowed us to design a specific PCR primer that was successfully used to amplify region A. The new reverse primer LCR2, that recognize all Trichoderma isolates, was identified in region B and confirmed for its specificity on the DNA of fungi belonging to other Ascomycota genera. Results obtained showed that IGS region seems to be an interesting and versatile tool for phylogenetic analysis, for resolving some taxonomic problems and for constructing specific primer useful for different purposes.
文摘The soil is a complex system where processes have direct influence on crop nutrition and plant health. Unfortunately, most of the agricultural soil management practices, compact them producing poor oxygenation, low benefic microorganism populations and metabolic disorders in plants. Those factors induce abnormal plant development and predisposition to the attack of soil borne plant pathogens as: Sclerotium cepivorum, Sclerotium rolfsi, Sclerotinia sclerotiorum, Rhizoctonia solani, Rosellinia spp. But also, some air borne pathogens as Colletotrichum sp., are more aggressive under those conditions. In Costa Rica some practical trails done by farmers, have shown that the addition of Trichoderma spp. to organic fertilizers like vermicompost, Bocashi, and other composts, has a positive effect on the structure and microbial diversity, that improves nutrient movement in plants and pathogen suppression. Vegetative material of leather fern (Rumohra adiantiformis) infected by Rosellinia spp., planted with bocashi amended with. T. asperellum (T. harzianum), showed more tip root growth and new fern rhizomes. Also the plants produced higher number of fiddleheads and high quality fronds. Non-treated material showed a total loss. In some leaf vegetables as lettuce the use of vermicompost followed by Trichoderma viride application, inhibited S. sclerotiorum development on the crop, in this study sclerotia were infected and plant yields were increased. Compost previously inoculated with Trichoderma, inhibited 100% the Botrytis and R. solani infection, in nurseries, and plant nutrition was improved. The observed results are attributed to the antagonistic effect of Trichoderma on soil and airborne pathogens, production of growth regulators, solubilization of some microelements and better mineral absorption with the development of more roots and elimination of diseased roots. As conclusion, the organic substrates inoculated with Trichoderma spp., besides the organic matter source, they improve the structural characteristics of soil, promote the biochemical processes, increases the level of growth regulator substances and inhibit plant disease as well.
文摘A series of highly taxonomically diverse Trichoderma strains were investigated using proteomic approaches, to investigate the utility of protein profiles as taxonomic markers and to identify proteins of potential economic importance. Initial studies have focused on a comparison of single strains of T. aureoviride, T. saturnisporum, T. polysporum, T. longbrachiatum and T. spirale, along with two strains of T. harzianum. All seven strains were grown in synthetic medium supplemented with 2%(w/v) glycerol, to maximize the diversity of extracellular protein production. Samples of secreted protein were separated by 2D gel electrophoresis and will be characterized by MALDI-TOF peptide fingerprinting.
文摘From over 800 fungal strains of Tri-choderma Spp. , 6 strains were foundto greatly inhibit the growing of Rhi-zocotonia solani, the pathogen of ricesheath blight in dual culture. Amongthem, strain T3 was the best antago-nist, which reduced the growing ofthe pathogen by 52.54% (Table 1).
文摘Two different species, Trichoderma viride TV10 and Trichoderma harzianum TH12 from 30 Trichoderma isolates were selected out based on their high growth inhibition of the phytopathogen Sclerotinia sclerotiorum (Lib) de Bary, which reached 84.44% and 100%, respectively. Their untreated culture filtrates (CF) and culture filtrates treated with heat (CFH) also were tested for growth inhibition of the pathogen in potato dextrose agar (PDA). Morphological and molecular characterisation by internal transcribed spacer (ITS) PCR provided consistent identification of these isolates. The degree of infection and disease index (DI) of S. sclerotiorum were examined in Brassica napus (AACC) and Raphanus alboglabra (RR) and Brassica alboglabra (CC). The results revealed that Raphanus alboglabra showed higher disease resistance than that of B. napus. Biotic elecitors T. harzianum TH12 and T. viride TV10 and their CF and CFH demonstrated the ability to cause induced systemic resistance (ISR) in B. napus and Raphanus alboglabra against sclerotinia stem rot (SSR) disease. Furthermore, a high ability to reduce the degree of infection and DI in B. napus with the biotic elicitors T. harzianum TH12 and T. viride TV10 was observed, with numbers reaching 7.22% to 6.67% and 17.78% to 11.67%, respectively. When CF were used, reached 20.00% to 16.67% and 33.33% to 23.33%, respectively;with CFH, values reached 35.00% to 21.67% and 37.78% to 28.33%, respectively. While in Raphanus alboglabra the degree of infection and DI reached 0.00% and 0.00% with all biotic elicitors treatments. These results show that biotic elicitor treatments significantly (P B. napus and Raphanus alboglabra ranked as most effective. This study showed for the first time the ability of genotype Raphanus alboglabra (RRCC) to demonstrate resistance against S. sclerotiorum with or without treatment by biotic elicitors and the ability of genotype B. napus (AACC) to demonstrate resistance to the pathogen after treatment with biotic elicitors.
