Cuantificación e identificación morfométrica y molecular de nematodos del género Meloidogyne spp. en plantas de tomate riñón (Solanum lycopersicum)

Abstract

In Ecuador, annual production of tomato (Solanum lycopersicum) is approximately 62 thousand tons per year. However, economic losses have been reported that represent between 24 to 33% of the crop, due to the presence of nematodes of the genus Meloidogyne spp. that affect two main conditions: fruit quality and plantation yield. The objective was to quantify and identify, through morphometric and molecular techniques, the nematodes of the genus Meloidogyne spp. in tomato indicator plants for their susceptibility to attack. Morphological and morphometric comparisons were made based on 8 measurement patterns and were complemented with the molecular identification by polymerase chain reaction (PCR) of the taxonomically important genes 28S, 5S and 18S. Subsequently, the D2D3 fragment of the rDNA was amplified with primer pair D2A and D3B, the untranscribed spacer region (IGS) between 5S and 18S with primers 194 and 195 and the SCAR sequences with specific primers for the species M. incognita (MI-R and MI-F); M. arenaria (Far/Rar) and M. javanica (Fjav/Rjav). PCR evaluations allowed the detection of the genus Meloidogyne spp. and the identification of the species M. incognita; the presence of the species M. arenaria and M. javanica was not determined. This study suggests adopting the use of different identification tools for a correct diagnosis, in order to improve the evaluation of the diversity of the genus Meloidogyne spp. and provides data on the identification of this phytopathogen in tomato crops in Ecuador.