The aim of this work was to evaluate two paternity cases by microchip electrophoresis and the validation of the methodology by comparison of the results with those obtained in a commercial genetic analyzer. It was observed that when working with tetranucleotide regions, in which the minimal difference between the alleles was only four base pairs, the commercial microchip system did not present the resolution and repeatability needed. Nevertheless, the relative standard deviation was between 0 and 1.2% and the fragments detected were within the expected size ranges as described in the literature.

O gênero Fusarium é responsável por doenças em diversas plantas economicamente importantes. Entre estas doenças, destaca-se a malformação da mangueira, causada pelo fungo Fusarium subglutinans. O objetivo deste trabalho foi desenvolver oligonucleotídeos iniciadores para reação em cadeia da polimerase (PCR), específicos para o fungo F. subglutinans da mangueira. A amplificação de DNA de oito Fusarium spp. de diferentes hospedeiros, usando o oligonucleotídeo randômico UBC-41 (TTAACCGGGG), produziu um fragmento de aproximadamente 1.300 pb somente para o fungo da mangueira. Tendo em vista que padrões de bandeamento por RAPD não são considerados confiáveis devido à baixa reprodutibilidade dos resultados, o fragmento diferencial foi eluído do gel de agarose, purificado, clonado e seqüenciado. As seqüências nucleotídicas foram utilizadas para identificar e sintetizar quatro pares de oligonucleotídeos específicos, denominados Fs 5, Fs 13, Fs 14 e Fs 15. DNAs de Fusarium spp. de outros hospedeiros (alho, amendoim, cana-de-açúcar, ciclâmen, ervilha, melão e trigo), da planta de mangueira cv. Tommy Atkins sadia e de outros cinco isolados de F. subglutinans de mangueira sintomática, foram submetidos à amplificação com os pares de oligonucleotídeos. Fragmentos amplificados foram visualizados somente para F. subglutinans de mangueira, demonstrando assim a especificidade dos oligonucleotídeos SCAR desenhados.

The Fusarium genus is responsible for serious diseases in many economically important crops. Among these diseases it is distinguished the mango flower malformation, caused by the fungus Fusarium subglutinans. The objective of this work was to develop specific oligonucleotide primers for the polymerase chain reaction (PCR) targeting the mango flower malformation by fungus F. subglutinans. The DNA amplification of eight Fusarium spp. collected from different hosts making the use of a random oligonucleotide primer UBC-41 generated a fragment of approximately 1300 pb in size, specifically for the mango flower malformation fungus (Fusarium subglutinans). Since standard RAPD banding patterns are not considered reliable because of their low results of reproducibility, the distinctive fragment was eluted off the agarose gel, purified, cloned and then sequenced. The nucleotide sequences were used to identify and also to synthesize four pairs of specific oligonucleotide named herein Fs 5, Fs 13, Fs 14 and Fs 15. Other Fusarium spp. DNAs sampled from other hosts (garlic, peanut, sugarcane, cyclamen, pea, melon and wheat), from a healthy mango tree cv. Tommy Atkins and other six isolates from symptomatic mango plants were submitted to PCR amplification with these pairs of oligonucleotide. Only fragments from the mango tree fungus Fusarium subglutinans were visualized, showing this way the SCAR oligonucleotide specificity.