Population and initial parasitic characterization of Meloidogyne exigua and Meloidogyne paranaensis on coffee trees

Abstract

The diverse endophytic stages of the life cycle of species of the Meloidogyne genus are related to parasitism in the host plant. In this study, the objective was to analyze Meloidogyne exigua (Mex) and Meloidogyne paranaensis (Mpar) in roots of coffee trees, through quantification of life cycle phases and characterization by scanning electron microscopy (SEM) the initial symptoms at 4, 7, 10, 17, 24, 31, 38 and 45 days after inoculation (DAI). The vermiform J2 stage of Mex was observed until 17 DAI, with populational variation among coffee trees. The same phase with Mpar was observed until 7 DAI, without populational differences flutuaction in Mex sausage-shaped J2 population was observed between 17 and 31 DAI and intensified for the and juveniles of the third and fourth stages (J3/J4) with reduction in the final of this period on Apoatã and IPR 100. The sausage-shaped stage of Mpar was observed at 10 DAI and J3/J4 at 17 DAI, with a higher population in Mundo Novo coffee trees. At the end of the cycle, the female population with eggs of Mex was higher in the Mundo Novo and genotype 2, and the formation of young females with eggs of Mpar was low in all coffee trees except for cv. Mundo Novo. The symptomatology of Mpar and Mex was evidenced by longitudinal cracks in the roots with Mpar and rounded galls, an apparent mass of eggs on the roots with Mex at 45 DAI.