Identification of coffee root-knot nematodes based on perineal pattern, scar markers and nuclear ribosomal DNA sequences

I. Herrera, T. Bryngelsson, A. Monzon, M. Geleta

Abstract


The present study aimed at identifying Meloidogyne species attacking coffee in Nicaragua. Eighteen isolates collected from coffee plantations across Nicaragua were identified. The study was based on perineal patterns of egg-laying females, SCAR markers and partial sequences of 18S and 28S nuclear rDNA. Two Meloidogyne species: M. exigua and M. incognita were identified and characterized. The combined sequences of 18S and 28S nuclear rDNA showed that both species were comprised of single haplotypes. Meloidogyne exigua was widespread and was isolated from all eighteen coffee plantations whereas M. incognita was identified in only one. Meloidogyne exigua has unique variable sites within the 18S and 28S rDNA regions when compared to several Meloidogyne species, including those sharing similar reproductive mechanisms. These variable sites can be used to develop new species specific SCAR markers for identification of M. exigua.

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