Title

Variabilidad genética para virulencia en (fusarium oxysporum f. sp. lycopersici (sacc.) snyder y hansen (fol), fuentes de resistencia y forma de herencia en especies de (lycopersicon)

Author

ADA ASCENCIO ALVAREZ

Contributor

ALFONSO LOPEZ BENITEZ (Thesis Adviser)

FERNANDO BORREGO ESCALANTE (Thesis Adviser)

SERGIO ALFREDO RODRÍGUEZ HERRERA (Thesis Adviser)

ALBERTO FLORES OLIVAS (Thesis Adviser)

Access level

Open Access

Summary or description

"En el presente trabajo se inocularon 29 aislamiento monospóricos de Fusarium oxysporum f. sp. lycopersici (Fol), en materiales diferenciales para observar su variabilidad genética (Bonny Best, Manapal, Walter e I3R3), con una suspensión conidial (107 ml l-1). Se extrajo ADN, el cual se amplificó usando la reacción en cadena de la polimerasa (PCR), de secuencias espaciadoras intergénicas con los iniciadores IGSF 5’ CTG AAC GCC TCT AAG TCA G 3’ e IGSR 5’ AAT GAG CGA TTC GCA GTT TC 3’; y se realizó un análisis del patrón de bandas generada por la técnica de polimorfismos en la longitud de los fragmentos de restricción (RFPLs), usando las enzimas de restricción: EcoRI, RsaI, DraI e Hinf. Se utilizaron 27 accesiones de diferentes especies del género Lycopersicon para buscar fuentes de resistencia procedentes del Conservation Genetic Resources Program of University of California, Davis; las cuales se inocularon y se evaluaron de la misma forma que con los materiales diferenciales. Se utilizaron poblaciones segregantes F2 producto del entrecruzamiento de progenitores tolerantes y susceptibles a la raza 3 de Fol. La evaluación por medios convencionales se basó en la respuesta típica de resistencia vertical a través de la observación de síntomas (plantas sanas o enfermas); en la metodología por medios moleculares se hizo un análisis estadístico (matriz de dismilaridad genética por apareamiento simple); el análisis fenético se realizó con el programa de análisis multivariado de taxonomía numérica (NTSYS-pc versión 2.3); la matriz de similitud se calculó con el coeficiente DICE. Para definir el tipo de herencia se utilizó la prueba G y para calcular los valores de dicha prueba, se empleó un software (McDonald et al., 1996). Se detectó la presencia de tres razas de Fol. en los lotes muestreados en Culiacán, Sinaloa; el 24 % corresponde a la raza 1, 14% a la raza 2 y 62% a la raza 3. A través de medios moleculares, no existe variabilidad entre las cepas evaluadas; sin embargo, hay diferencias genéticas que permiten diferenciar las razas presentes. De los genotipos evaluados con posibles fuentes de resistencia todos fueron susceptibles a la raza 1, 16 resistentes a la raza 2 y 4 resistentes a la raza 3, siendoL. esc. cv. motelle; Lycopersicon peruvianum y Lycopersicon pimpinellifolium. Al evaluar el tipo de herencia se observó que las especies esculentum, peruvianum y pimpinellifolium presentaron genes de resistencia vertical a la raza 3. Las frecuencias genéticas 3:1 de plantas (resistentes y susceptibles) en las poblaciones segregantes, fueron similares, ya que en todos los casos el valor G (2.8, 0.68 y 1.35, respectivamente) tienen una p 0.05, indicando una herencia mendeliana simple."

There were collected 102 samples stem with Fusarium oxysporum f sp lycopersici (Fol) symptoms of tomatoes commercial varieties from Culiacán Sinaloa. The fungi was isolated, purified and morphologically identified, producing monosporic isolates. The differential genotypes used were Bonny Best, Manapal, Walter and I3R3; those were inoculated in a Fol conidial suspension of 107 ml l-1 containing every possible race of Fol using the immersion of root with small wounds. The high quality DNA was obtained and amplified using the polymerase chain reaction (PCR), of sequencing of the intergenic spacer, using primers IGSF 5’ CTG AAC GCC TCT AAG TCA G 3’ e IGSR 5’ AAT GAG CGA TTC GCA GTT TC 3’. It was carried out a polymorphism patterns analysis using the restriction fragment length polymorphisms (RFLP’s) technique, using the restriction enzymes: EcoRI, RsaI, DraI and Hinf to find variability in the monosporic isolates. There were used 27 accessions from the Conservation Genetic Resources Program of University of California, Davis, of 48 different genera of Lycopersicon to identify genetic sources of resistance; the inoculation and evaluation were in the same way that differential genotypes. Later, the segregants F2 populations resulting of resistant ant susceptible race 3 of Fol. parent crossover were evaluated using the typical symptoms of vertical resistance answering (sick and health plants). In the molecular methodology a statistical analysis was made to obtain a dissimilarity matrix analysis by simple mating; assigning digit 1 for presence and digit 0 for absence. The phenetic analysis was did it using a multivariate analysis of numeric taxonomy (NTSYS-pc ver 2.3). The similarity matrix was calculated with the DICE coefficient. To define the inheritance was used the G test using the software proposed by McDonald et al., 1996. The differential genotypes responses detected the 3 races of Fusarium oxysporum f. sp. lycopersici presence in the Culiacán Sinaloa commercial production lots. From all the isolations, 24% presented race 1, 14% race 2 and 62% race 3. Through the molecular analysis it was determined that the variability among monosporic isolates does not exist; however, there are genetic differences that allow defining the races. In the evaluated genotypes it was found that all of them were susceptible to race 1, 16 were resistant to race 2 y 4 resistant to race 3, standing out an improved genotype (L. esc cv. motelle) and 2 wild (Lycopersicon peruvianum and Lycopersicon pimpinellifolium). The peruvianum specie had booth vertical resistance to races 2 and 3, showing it like a potential resistance source, which was originated in the Andeane region where it was possible the resistance develop to the different Fol. races. The peruvianum and pimpinellifolium species had resistance to race 3. The 3:1 genetic frequencies of resistant and susceptible plants in segregant populations were similar, since the G value (2.8, 0.68 and 0.02, respectively) had a p 0.05, showing a simple Mendelian inheritance. In this way, the pimpinellifolium specie has vertical resistant alleles to races 2 and 3.

Publish date

December, 2006

Publication type

Doctoral thesis

Publication version

Published Version

Format

application/pdf

Language

Spanish

Audience

Students

Researchers

Source repository

Repositorio Digital CID-UAAAN

Downloads

183

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