Resumo

RAIGOSA GOMEZ, Natalia et al. GENETIC VARIABILITY OF ISOLATES OF Phytophthora infestans (Mont.) de Bary IN SOLANACEOUS CROPS FROM COLOMBIA. Rev.Fac.Nal.Agr.Medellín [online]. 2009, vol.62, n.1, pp. 4761-4771. ISSN 0304-2847.

The level of genetic variability of 35 isolates of Phytophthora infestans obtained from different hosts and geographical regions of Colombia was studied through mitochondrial haplotypes and RAPD techniques. Results suggested the existence of mitochondrial haplotypes Ia affecting tree tomato (Solanum betaceum) and IIa in potato, which are associated with genetic lineages EC-3 and EC-1, respectively. However, three isolates obtained from tomato (S. lycopersicum), capsicum (Capsicum sp.) and pear melon (S. muricatum), require an additional analysis, due to lack of correlation among the restriction profiles generated and the mitochondrial haplotypes reported in literature. RAPD analysis showed the occurrence of variability within the two genetic lineages. Interestingly, isolates obtained from tree tomato (EC-•3) were divided in two groups, related with a genetic distance of 0.17. These findings indicate that it is important to consider sources of asexual variation for analysis of population structure of this oomycete and therefore for designing control strategies of diseases caused by P. infestans in solanaceous crops of economic importance.

Palavras-chave : Late blight; mitochondrial haplotypes; molecular markers; RAPD; Solanaceae.