Análisis de secuencias polimórficas del núcleo y cloroplasto por conformación de ADN simple banda en introducciones de Cucurbita moschata Duchesne procedente de Mesoamérica

Abstract

The aim of this investigation was the genetic characterization of 218 accessions of Cucurbita moschata Duchesne a squash, with sorne morphologic characteristics that make it of agronomic interest, which are part of the germoplasm bank of the CATIE . The accessions carne from Mexico and Central America; also, we have a genotype from Curacao, Colombia, Peru and tbe Rusian Federatíon. Polymerase chain reaction (PCR) and single strand conformation polymorphism analysis (SSCP,) were used for the analysis of the regions amplified with ITSl-ITS2 nuclear primers and tmL-trnF chloroplast primers. Haplotypes were constructed according to band pattem and SSCP gels. 25 and 24 haplotypes were found, using ITSI-ITS2 and tmL-tmF markers, respectively. We found unique haplotypes with botb markers, like the 20 and 21 from Mexico, 14 and 24 from Guatemala, six from Honduras, 13 and 16 from Nicaragua, and 17 and 25 from Costa Rica with the ITSI-ITS2 SSCP gels. While with the tmL-tmF were the haplotype seven from Colombia, eight from Guatemala. nine from Honduras, 10 from Nicaragua, 12, 13 and 17 from Mexico, 21, 22 and 23 from Costa Rica and 24 from El Salvador. This information can be used to identify others accessions of agreement to them place of origin. We selected and sequenced two inclivíduals of each haplotype with the trnL-trnF marker. We established tbat the six haplotype obtained from the chloroplast sequences were common among the nine accessions of popuJations from Costa Rica, Mexico, Guatemala, Nicaragua, and Honduras. We could determínate the genetic variation among the accessíon of squasb from Mesoamerica using the ITSI-ITS2 nuclear primers and tmL-tmF chloroplast primers.