“Influencia de trichoderma spp endófito sobre el crecimiento e inducción de resistencia al estrés hídrico en cacao (theobroma cacao l.)”

• Autor: Trigozo Bartra, Erick
• Formato: tesis de grado
• Fecha de Publicación: 2012
• Institución: Universidad Nacional de San Martin - Tarapoto
• Repositorio: UNSM-Institucional
• Lenguaje: español
• OAI Identifier: oai:repositorio.unsm.edu.pe:11458/1576
• Enlace del recurso: http://hdl.handle.net/11458/1576
• Nivel de acceso: acceso abierto
• Materia: cacao; climas tropicales; estrés hídrico

The cocoa being cultivated in tropical climates, needs a good distribution of water throughout the year, as it is very sensitive to the lack of moisture in the soil, and the production is greatly affected by periodic droughts and seasonal rains. The use of Trichoderma spp could be an alternative to solve these problems, as there are reports which indicate that these organisms have the benefits of developing resistance to water stress in the plant. In order to determine the influence of endophyte Trichoderma species (TE) on the growth and induction of resistance to water stress in cocoa (Theobroma cacao L.) were evaluated 12 isolates of TE from native cocoa. For endophytic colonization of cacao seedlings were used two methods of inoculation, M1: seed, and M2: soil infestation. All isolates of TE were able to colonize cacao plants of 16 days old at the two inoculation methods. The highest endophytic colonization was presented with the M1 with 63,54% and the isolates TE-39 (80,21%) and TE-50 (78,13%) were better able to colonize by both methods. Also, higher values of growth rate (TC), stem diameter (SD), root length (LR), number of leaves (NL), dry weight of biomass aeria (PS-A) and root dry weight (PS-R) were given with the M1, plant height (PH), hypocotyl height (AH) and epicotyl height (AE) with M2; being, the isolates TE-17, TE-72, TE-39 and TE-126 that generated greater TC compared to the control. However, TE-81 generated greater AP (27,69cm), AH (12,5cm), AE (15,19cm) and NH (5,9); TE-72 generated greater SD (3,94mm) and TE-22 increased LR (453,23cm). However, for the PS-A and PS-R, TE-22 (PSA= 1,16g, PS-R=0,23g) and TE-81 (PS-A=1,15g; PS-R=0,22g) were the best, compared to the control (PS-A=1,11g; PS-R=0,21g). At 6 and 9 days after subjecting to water stress (DDSE), plants inoculated with TE by M1 had lower degree of wilting plant (GM), higher absolute rate of root growth (TAC-R), LR, however, was obtained in M2 increased percentage of water. Plants colonized with TE-17 had lower GM (0,91), at 6 DDSE, followed by TE-22, TE-50, TE-20, TE-126, TE-74, TE-3, TE-39, TE-72 and TE-105 obtained degrees between 2,35 to 2,95 compared to control (without water) that obtained a GM of 3,2. However, at the 9DDSE TE-17 (2,53) was the only that generated minor GM in comparison to the control (5). With respect to the absolute rate of growth (TAC), the isolates TE-126 (0,0145g.día-1), TE-54 (0,0088g.día-1) and TE-39 (0,0053g.día-1) generated greater TAC-R than the control without water (-0,0057g.día-1): likewise, TE-17 (0,0183 g.día-1) and TE-126 (0,0181g.día-1) generated higher absolute growth rate aerial part of the plant (TACA). In the results of root water percentage (% A-R) and aerial part of the plant (%A-A) indicate that at 6 and 9 DDSE, TE-17 (%A-A=63,57%; %A-R=59,99%) generated higher %A outperforming to the control (%A-A = 45,97%, %A-R=56,67%). However, TE-54 (510,92cm), TE-3 (499,56cm) and TE-105 (480,23cm) generated greater LR, outperforming to the controls ranging from 415,62 to 476,86cm.