Título
Genética de poblaciones, resistencia y expresión diferencial de rhizoctonia solani kühn a fungicidas, su respuesta a antagonistas y fito químicos.
Autor
FRANCISCO CASTILLO REYES
Colaborador
FRANCISCO DANIEL HERNÁNDEZ CASTILLO (Asesor de tesis)
GABRIEL GALLEGOS MORALES (Asesor de tesis)
ALBERTO FLORES OLIVAS (Asesor de tesis)
RAÚL RODRÍGUEZ HERRERA (Asesor de tesis)
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
"Se determinó la variabilidad genética de 57 cepas a nivel de grupo de anastomosis (GA) de R. solani, aislados de planta y tubérculos procedentes de lotes comerciales del cultivo de papa en las zonas agrícolas de los estados: Coahuila (Huachichil, San José del Vergel, San Juan del Prado, La Purísima), Nuevo León (Arramberry, El Potosí, Lucio Blanco, San Rafael, San Joaquín, Lote 17 y Lote 28), Chihuahua (Janos y Nuevo Casas Grandes), Sonora (Obregón) y de tubérculos importados de Canadá, a través de la amplificacion de la region 18 Ls del rADN usando los Iniciadores RS1 (5 -CCTGTGCACCTGTGAGACAG-3 L) y RS4 (5 -TGTCCAAGTCAATGGACTAT-3 L) (Camperota et. al. 2000) y su posterior restriccion con 4 enzimas (MseI, AvaII, HincII, y MunI). Asi como bioensayos para determinar los niveles de resistencia a los fungicidas Pencycuron y Tiabendazol y el comportamiento de los individuos resistentes y susceptibles a antagonistas microbianos y a fitoquimicos extraidos de plantas"
"In this study was determined the genetic variability of 57 strains at anastomosis group (GA) level of of R. solani, isolated from plants and tubers from commercial batches potato in different agricultural areas: Coahuila (Huachichil, San Jose del Vergel, San Juan del Prado, La Purisima), Nuevo Leon (Arramberry, El Potosi, Lucio Blanco, San Rafael, San Joaquin, Lot 17 and Lot 28), Chihuahua (Janos and Nuevo Casas Grandes), x Sonora (Obregon) and imported tubers from Canada. Rhizoctonia groups were identified PCR amplification of rDNA 18's using the follow primers RS1 (5'-CCTGTGCACCTGTGAGACAG-3 ') and RS4 (5'-TGTCCAAGTCAATGGACTAT-3') (Camperota et. al., 2000) and subsequent restriction with 4 enzymes (Mse I, Ava II, Hinc II, and Mun I). Bioassays were perfomed to determine the Rhizoctonia resistence levels to the Thiabendazole and Pencycuron fungicides and behavior of resistant and susceptible individuals to microbial antagonists and phytochemicals extracted from semidesert plants. The restriction patter resulted that the Rhizoctonia strains were identified as AG11 5.26%, AG1-1B 14.03% and AG380.7%, this classification coincides with the percentages reported by Alonso et. al. 1994, Virgin et. al. 1996, Carling et. al. 1998. The high presence of GA3 can be correlated with the spread of group by tuber seed. The susceptibility determination of the Rhizoctonia strains to thiabendazole and Pencycuron fungicides shows that the growth of all strains of R. solani was inhibited with an IC50 of 0.014-0.039 mg ai / L pencycuron, reports literature indicates that the IC50 of a susceptible strain of R. solani is 0.01 mg / L, with these data it was determined that the resistance factor (FR) of studied strains fluctuated between 1.4 to 3.945. For thiabendazole all strains were inhibited with IC50 of 0.82 to 2.91 mg ai / L, so it is in concordance to results reported by Leach and Murdoch (1985), where strains with IC50 values of less than 3 mg / L are sensitive to thiabendazole fungicide. Different AG showed heterogeneity in sensitivity to the thiabendazole and pencycuron fungicides being AG11 and AG1-1B the most tolerant groups. xi The response of moderately resistant to pencycuron R. solani was evaluated against extracts from Larrea tridentata (G), Flourensia cernua (H), Agave lechugilla (L), Yucca filifera (Y), Carya illinoensis (R), Opuntia ficus-indica (N) and Lippia graveolens (O) obtained using different solvents (ethanol (E), water (H), lanolin (L) and cocoa butter (M)). In this study were found differences on mycelia growth inhibition from 0% to 100%. Mycelia growth inhibition was extract doze dependent, as extract concentraction increase, Tukey mean comparison indicates that: Carya / Ethanol 3000, Lippia / Lanolin, Opuntia / ethanol, Agave / ethanol and Flourensia / ethanol at doses higher than 200, Flourensia / butter with doses> 1000, Larrea / lanolin at doses> 2000 ppm of polyphenols have an effect of 100% inhibition of R. solani mycelia. The IC50 of each extract on R. solani was highly variable; the lowest IC50 was obtained with F. cernua in ethanol to 16.3 ppm and the highest with O. ficus-indica in cocoa butter to 9.9 X106ppm. Studies for isolation antagonist microorganisms from cactus, agave, palm, governor, mesquite and lechuguilla rhizosphere againt R. solani allowed the identification of 16 Bacillus strains, which were identified by morphological, Gram and endospore staining and rDNA 16´s secuencing. The results of growth inhibition in vitro by dual technique express a range of 40.4 to 67% on the growth mycelia inhibition of fungicide resistant R. solani strains. Seven of these strains were identified by 16'S rDNA sequencing, five on B. subtilis, one on B. pumilus and one on B. atrophauas"
Fecha de publicación
1 de enero de 2012
Tipo de publicación
Tesis de doctorado
Versión de la publicación
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application/pdf
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Español
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Repositorio Orígen
Repositorio Digital CID-UAAAN
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