EVARISTO, Isabel; TENREIRO, Rogério    COSTA, Rita. Caracterização Molecular de Genótipos Seleccionados de Pinheiro Manso para o Controlo da Qualidade do Pinhão. []. , 15, 2, pp.139-170. ISSN 0870-6352.

^lpt^aPara analisar a diversidade genética inter e intra populações de P. pinea, foram seleccionadas 25 diferentes proveniências oriundas de sete países da orla Mediterrânea (Portugal, Espanha, Itália, Grécia, Marrocos, Turquia e Israel) e sete povoamentos de três Regiões de Proveniência Portuguesas. Estas populações foram analisadas recorrendo a diferentes tipos de marcadores moleculares RAPD (Random Amplified Polymorphic DNA), cpSSR (chloroplast Simple Sequence Repeat), AFLP (Amplified Fragment Length Polymorphism) e SSAP (Sequence Specific Amplification Polymorphism). No caso particular dos microssatélites de cloroplasto (cpSSR), não foi detectada variabilidade genética uma vez que se obteve um único haplótipo em todas as populações analisadas. No entanto, com os restantes marcadores detectaram-se diferentes graus de polimorfismo. Com os RAPD, recorrendo a 15 primers aleatórios registou-se 52% de polimorfismo. Os nossos resultados demonstraram que os marcadores baseados em retrotransposões (SSAP) foram mais informativos do que os baseados em AFLP. Assim, com os SSAP, foram analisados 232 fragmentos distintos, dos quais 175 se revelaram polimórficos (75%), enquanto que para os AFLP, com as três combinações de primers (EcoRI/MseI), se obtiveram 132 fragmentos, dos quais 75 (57%) foram polimórficos. A maior variabilidade genética encontrada registou-se dentro das populações e o índice de diferenciação F_ST variou de 7% com AFLP a 11%, com SSAP.^len^aIn order to assess the genetic diversity, within and among Pinus pinea populations, 25 different provenances from seven countries (Portugal, Spain, Italy, Greece, Morocco, Turkey and Israel) and seven Portuguese populations originated from three Provenance Regions were selected. These populations have been analysed using different types of molecular markers: RAPD (Random Amplified Polymorphic DNA), cpSSR (chloroplast Simple Sequence Repeat), AFLP (Amplified Fragment Length Polymorphism) and SSAP (Sequence Specific Amplification Polymorphism). In the case of cpSSR, no genetic variability was revealed since a single haplotype was obtained for all the populations analysed. However, with the other markers different levels of polymorphism were obtained. RAPD profiles revealed 52% of polymorphic fragments with 15 different primers. Our results showed that SSAP approach was more efficient to retrieve information than AFLP analysis, leading to the highest number of polymorphic fragments obtained and higher levels of estimated genetic diversity. With SSAP, 232 distinct fragments were scored, and 175 were polymorphic (75%), while with the three AFLP primer combination (EcoRI/MseI) 132 distinct fragments were produced, with 75 (57%) being polymorphic. The greater genetic variation was found mainly within populations and the fixation index F_ST averaged over loci ranged from 7% with AFLP to 11% with SSAP.^lfr^aPour évaluer la diversité génétique intra et inter populations de P. pinea, nous avons sélectionné 25 différentes provenances originaires de sept pays méditerranéens (Portugal, Espagne, Italie, Grèce, Maroc, Turquie et Israël) et sept peuplements dans trois régions de provenance portugaises. Ces populations ont été analysées avec le recours à divers marqueurs moléculaires: RAPD (Random Amplified Polymorphic DNA), cpSSR (chloroplast Simple Sequence Repeat), AFLP (Amplified Fragment Length Polymorphism) e SSAP (Sequence Specific Amplification Polymorphism). Dans le cas particulier des microsatellites chloroplastiques (cpSSR), la variabilité génétique n'a pas été signalée, étant donné qu'on a trouvé un seul haplo type commun à toutes les populations analysées. Cependant, avec les autres marqueurs moléculaires on a obtenu différents polymorphismes. Chez les RAPD, et en utilisant 15 primes aléatoires, on a enregistré 52% de polymorphisme. Ainsi, nos résultas ont démontré que les marqueurs basés en rétrotransposons (SSAP) ont été plus informatifs que les AFLP. En effet, des 232 fragments analysés avec SSAP 75% ont présenté des niveaux de polymorphisme, tandis que, avec les AFLP et les trois combinaisons de primes (EcoRI/MseI), seulement 57% ont été polymorphiques. On a constaté une plus grande variabilité génétique intra populations et l'index de différentiation F_ST a divergé de 7% avec les AFLP et 11% avec les SSAP.

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