Browsing by Autor "Miranda Claudia"

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Selección de cepas de Trichoderma spp. generadoras de metabolitos secundarios de interés para su uso como promotor de crecimiento en plantas cultivadas
(Universidad Internacional de La Rioja, 2013) Ortuño Noel; Miranda Claudia; Mayra Claros
The Trichoderma Trichoderma interaction of 35 strains was studied becau\nse of the fungal potential to synthesize\nSecondary Metabolites (MS), such as the 3-indoleacetic acid (IAA), by using dual confrontations in solid crop of\npotato-dextrose-agar (PDA) as a selecting method for forming strains of "defense\nbarrier" between 0.5-0.7cm with an\noptimum width selection. 20\ndual confrontations were identified. These\nwere replicated in liquid culture potato-\ndextrose broth (PDB) under constant stirring. After 9 days\nof growth, the filtration was performed to separate the\nmetabolites synthesized by the fungus mycelium formed. Th\nis substance of interest, containing the MS, was\ninoculated into two crops:\nLactuca sativa\nand Raphanus sativus. \nIt was found that the best treatments for testing are the\nLactuca sativa 3(BP-T0001-BPT0029), 4(BP-T0006-BPT0028),7(BP-\nT0007-BPT0024) confrontations and the\nindividual crop I (BP- T0028) as the best inducer strain\ns of growth and involving weight, length , root volume and\nleaf weight . For testing of\nRaphanus sativus, the best treatments are the confrontation 10 (BP- T0015 - BPT0025)\nand the individual K crop (BP-T0031) as inducers of root\nlength, diameter and bulb\nweight. The individual G crop\n(BP-T0024) and the chemical fertilizer\nQUI, inducers of leaf weight and the confrontation 3(BP- T0001-BPT0029) as inducer of root weight. Therefore, the MS synthesized by\nTrichodermaspp. MS during dual confrontations act as Growth Promoters in Plants (PGP)
The use of secondary metabolites extracted from <i>Trichoderma</i> for plant growth promotion in the Andean highlands
(Cambridge University Press, 2016) Noel Ortuño; José A. Castillo; Miranda Claudia; Mayra Claros; Ximena Soto
Abstract Agriculture in the Altiplano and Andean Mountains is experiencing threats to sustainability mainly due to intensive cultivation of quinoa driven by international markets. This recent export-oriented production system is causing the degradation of soils and reducing productivity, therefore, agro-technological innovations are necessary to sustain cropping systems while maintaining organic quality (mostly quinoa). In this work, we searched for native Trichoderma species associated with plants from the Andean highlands to obtain an environmentally friendly and organic alternative to chemical fertilizers. We obtained different Trichoderma isolates from quinoa, potato and maize roots and soil, which were identified as Trichoderma harzianum , as well as other species. Twelve of the isolates were cultured in pairs to stimulate the production and secretion of compounds of diverse chemical nature that we called collectively ‘secondary metabolites’ (SMs). Crude extracts of SMs were used to inoculate selected crops to determine their plant growth promoting potential compared with two commercially available controls, chemical fertilizer and a bio-fertilizer. Results showed that SMs significantly promoted lettuce and radish growth and increased quinoa grain yield. Indole acetic acid was detected in all SM extracts that promoted plant growth, suggesting that this plant regulator might be responsible for the plant growth promoting activity. In conclusion, the Trichoderma -derived SMs approach appears to be a promising, simple and accessible technology for small-scale farmers in order to insure the sustainability, affordability and accessibility of food production in the Andes.