Felipe Roberto Flores-de la Rosa
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María del Mar Jiménez-Gasco
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Jacel Adame-García
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Andrés Rivera-Fernández
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Mauricio Luna Rodriguez
Abstract
Fusarium oxysporum is an ubiquitous inhabitant of soils with an important role as an endophyte in several plant species, being a neutral, benefic or pathogenic endophyte. Neutral and pathogenic strains have been reported for vanilla crops (F. oxysporum f. sp. vanillae), and a polyphyletic distribution of pathogenic strains has been demonstrated. However, there is no study of a molecular genetic comparison between both groups associated with vanilla. This study is aimed to evaluate if a genetic differentiation is possible between both groups. Different microsatellite regions were amplified and data were used for genetic and statistic comparisons between pathogenic and non-pathogenic endophytes. Further, the Sequence Type of TEF-gen was determined and a phylogeny was constructed. Also, SIX gene presence was evaluated using universal primers. Results show that, based on microsatellite data, a differentiation between the two groups is not possible, however, UPGMA and CA analysis suggest that the pathogenic group is a subgroup of the non-pathogenic group. Phylogeny confirms that the ability to infect vanilla is a polyphyletic trait, but comparison with UPGMA shows that some strains have a similar genotype by convergent evolution. A Bayesian approach suggests that strains can be divided into three genetic groups. For SIX genes, amplification was not possible, thus, we hypothesized three possible explanations. Genetic differentiation among pathogenic and non-pathogenic F. oxysporum endophytes from vanilla is not possible with microsatellite data, which corresponds with the Horizontal Gene Transference hypothesis. However, the SIX genes were no-detected in any pathogenic strain, three hypotheses are planted to explain this results.
Dispersal and Differentiation of Deep-Sea Mussels of the GenusBathymodiolus(Mytilidae, Bathymodiolinae)
