RESUMO
The transferability of microsatellite markers developed for olive cultivars ( Olea europaea L.) has been tested and confirmed in the Olea complex. Thirty two genotypes, belonging to different taxa of the genus Olea, have been analyzed with four olive SSRs. Positive amplifications at all loci were obtained in 13 taxa (at least one accession per species). Sixty seven different alleles have been detected at the four loci analyzed. Polymorphic products have been observed at the inter- and intra-species level. Some SSR loci have shown multiple amplification products in some species. The high number of unique alleles has allowed the unambiguous discrimination of most accessions. Similarity coefficients and relationships among the Olea taxa have been calculated based on SSR amplification results. The reliability of SSRs as markers for intra-species variability evaluation has been confirmed while their use to explore relationships at the inter-species level is discussed, being dependent on the locus analyzed.
Assuntos
Marcadores Genéticos , Repetições de Microssatélites , Olea/genética , Folhas de Planta/genética , DNA de Plantas/genética , Amplificação de Genes , Variação Genética , Genótipo , Olea/crescimento & desenvolvimento , Filogenia , Reação em Cadeia da Polimerase , Sequências Repetitivas de Ácido Nucleico , Especificidade da EspécieRESUMO
ABSTRACT Microsatellite markers of Venturia inaequalis were developed using genomic libraries of V. inaequalis enriched for the simple sequence repeats (TC)(n) and (AAC)(n). Seven markers, three with (TC)(n) repeats and four with (AAC)(n) repeats, were selected for the analyses of 350 isolates of V. inaequalis collected from 11 sites in Europe. Polymorphism in the (TC)(n) repeats was higher than in the (AAC)(n) repeats. Nei's expected genetic diversity (H(E)) varied between 0.52 and 0.96 for the microsatellites containing (TC)(n) stretches and between 0.09 and 0.36 for the microsatellites containing (AAC)(n) stretches. Within-population diversity (H(S)) was very high with values ranging from 0.28 to 0.49, whereas differentiation among all European populations (G(ST)) was low with an average of 0.07. In the population from Ahrensburg (northern Germany) where isolates were mainly collected from apple varieties carrying the Vf gene, usually resistant to V. inaequalis, we showed a bottleneck effect with reduced diversity and loss of alleles. The great advantages of microsatellite markers over random amplified polymorphic DNA and polymerase chain reaction-restriction fragment length polymorphism markers are their high specificity, high polymorphism, good reproducibility, and unambiguous scorability.
