The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant h...The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant health, such as growth promotion, systemic resistance induction and fertility improvements. Some strains are powerful antibiotic producers, and their suitability for use in biocontrol systems must be carefully assessed. However, many other active strains have no antibiotic capacity, and these are likely to be more useful in food production systems since they have not adverse effects on important groups of beneficial soil organisms. We have assessed the performance of selected naturally occurring Trichoderma strains (singly and in combination) and developed TUSAL, a mixture of Trichoderma harzianum and T. viride that has demonstrated to be effective against major pathogens in sugar beet and horticulture. TUSAL, has been bulked up and tested under field conditions, showing positive effects on precocity and root development, and increasing the crop production in field trials carried out in different pathosystems. The environmental impact of TUSAL strains on beneficial organisms in the environment were assessed before release, and molecular detection methods were developed to monitor the presence and performance of strains in the field. In addition, Trichoderma protein extracts with high glucanase and chitinase activities, have also been obtained from wild type strains and their effectiveness as biofungicides was tested in laboratory and field conditions, defining the concentration of protein necessary to produce fungicide effects. The genes coding for protein production were introduced into suitable organisms for large-scale production in the laboratory, never released to the environment. The effect of these novel biofungicide proteins was studied separately and synergistically with Trichoderma conidia, and with minimal doses of chemical fungicides. Suitable active Trichoderma strains are being registered in the EU by the company NBT. Both Trichoderma strains and proteins are included in formulations patented as biocontrol agents.展开更多
OBJECTIVE： Plants produce a variety of useful bio- active materials that have been used to cure differ- ent ailments of human beings. With the same idea in mind, the crude methanolic extract and various fractions of ...OBJECTIVE： Plants produce a variety of useful bio- active materials that have been used to cure differ- ent ailments of human beings. With the same idea in mind, the crude methanolic extract and various fractions of Solanum surrattense were screened for antibacterial, antifungal, phytotoxic and heamag- glutination activities. METHODS： Standardized assays were followed for the determination of antibacterial, antifungal phy- totoxic and heamagglutination activity. RESULTS： The results of the antibacterial showed that crude methanolic extract was significantly ac- tive against Staphylococcus aureus （86%） The n- hexane fraction showed good activity against Pseu- domonas aerogenosa （66.6%） and Bacillus subtilus （66.6%）. The crude methanolic extract and various fractions were inactive against all test fungi. The crude methanolic extract, n-hexane, CHCI3 and aqueous fractions showed moderate phytotoxic ac- tivities of 46.67%, 40.00%, 33.34% and 33.34% re- spectively at 1000 pg/mL. The crude methanolic ex- tract and various fractions S. surrattense were un- able to aqqlutinate RBCs of the human blood indi-cating that this species lack phytolectins. CONCLUSION： The test sample showed significant antibacterial activity, no antifungal and heamagglu- tination activity while moderate phytotoxic was ob- served against Lemna minor L.展开更多
文摘The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant health, such as growth promotion, systemic resistance induction and fertility improvements. Some strains are powerful antibiotic producers, and their suitability for use in biocontrol systems must be carefully assessed. However, many other active strains have no antibiotic capacity, and these are likely to be more useful in food production systems since they have not adverse effects on important groups of beneficial soil organisms. We have assessed the performance of selected naturally occurring Trichoderma strains (singly and in combination) and developed TUSAL, a mixture of Trichoderma harzianum and T. viride that has demonstrated to be effective against major pathogens in sugar beet and horticulture. TUSAL, has been bulked up and tested under field conditions, showing positive effects on precocity and root development, and increasing the crop production in field trials carried out in different pathosystems. The environmental impact of TUSAL strains on beneficial organisms in the environment were assessed before release, and molecular detection methods were developed to monitor the presence and performance of strains in the field. In addition, Trichoderma protein extracts with high glucanase and chitinase activities, have also been obtained from wild type strains and their effectiveness as biofungicides was tested in laboratory and field conditions, defining the concentration of protein necessary to produce fungicide effects. The genes coding for protein production were introduced into suitable organisms for large-scale production in the laboratory, never released to the environment. The effect of these novel biofungicide proteins was studied separately and synergistically with Trichoderma conidia, and with minimal doses of chemical fungicides. Suitable active Trichoderma strains are being registered in the EU by the company NBT. Both Trichoderma strains and proteins are included in formulations patented as biocontrol agents.
文摘OBJECTIVE： Plants produce a variety of useful bio- active materials that have been used to cure differ- ent ailments of human beings. With the same idea in mind, the crude methanolic extract and various fractions of Solanum surrattense were screened for antibacterial, antifungal, phytotoxic and heamag- glutination activities. METHODS： Standardized assays were followed for the determination of antibacterial, antifungal phy- totoxic and heamagglutination activity. RESULTS： The results of the antibacterial showed that crude methanolic extract was significantly ac- tive against Staphylococcus aureus （86%） The n- hexane fraction showed good activity against Pseu- domonas aerogenosa （66.6%） and Bacillus subtilus （66.6%）. The crude methanolic extract and various fractions were inactive against all test fungi. The crude methanolic extract, n-hexane, CHCI3 and aqueous fractions showed moderate phytotoxic ac- tivities of 46.67%, 40.00%, 33.34% and 33.34% re- spectively at 1000 pg/mL. The crude methanolic ex- tract and various fractions S. surrattense were un- able to aqqlutinate RBCs of the human blood indi-cating that this species lack phytolectins. CONCLUSION： The test sample showed significant antibacterial activity, no antifungal and heamagglu- tination activity while moderate phytotoxic was ob- served against Lemna minor L.
