MOLECULAR CHARACTERIZATION AND DISTRIBUTION OF GLOBODERA PALLIDA IN THE MAIN POTATO PRODUCTION AREA OF COSTA RICA
Abstract
Since the first detection of Globodera pallida in Costa Rica in 2005, no further research has been done to study the presence and distribution of potato cyst nematodes in the country. The objectives of this study were to identify with molecular approaches the Globodera species and their distribution in Cartago, Costa Rica, and to determine the nematode intraspecific variability. Fourteen populations were collected at three elevations in the north of Cartago. In addition, one Globodera population collected from Alajuela (the second largest potato area in the country) was included in the molecular analysis. Fifteen populations were characterized with a segment of the ribosomal DNA, ITS1-5.8S-ITS2 (ITS), and the partial mitochondrial DNA gene, cytochrome b (cytb). A unique G. pallida haplotype from each marker was identified from 202 cytb sequences and 188 ITS sequences, suggesting a single introduction into the country and then spread. The phylogenetic relationships based on the cytb marker showed that the G. pallida populations from Costa Rica have a unique origin, possibly from the northern region of Peru. A pathotype identification study is suggested for the development of nematode-resistant potato varieties in Costa Rica.