Supplanting resistance of the Mi gene by root-knot nematode in industrial tomato in the Cerrado in Goiás State of Brazil

Rodrigo Vieira Da Silva,Bruno Eduardo Cardoso De Miranda,Fabricio Rodrigues Peixoto,João Pedro Elias Gondim,Brenda Ventura De Lima

doi:10.1590/0103-8478cr20180784

Rodrigo Vieira Da Silva, Bruno Eduardo Cardoso De Miranda + Show 3 more

Open Access

https://doi.org/10.1590/0103-8478cr20180784

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Abstract

ABSTRACT: Problems with root-knot nematodes, caused by genus Meloidogyne, can be controlled through the introduction of resistance genes in commercial varieties of tomatoes. However, plants of the hybrid ‘Heinz 9992’ for industrial processing, carrying the Mi gene, were reported with their roots severely infected in experimental cultivation in Goiás State of Brazil with symptoms typical of galls caused by Meloidogyne spp. After dissecting the galls present in the root samples, the females of the nematodes were removed and afterwards, performed the analysis of the perineal pattern and the biochemical characterization by electrophoresis of isoenzymes, besides the pathogenicity test. The pathogen analyzed was identified as Meloidogyne incognita. The pathogenicity test confirmed the supplanting resistance of the tomato hybrid with the Mi gene by this virulent population of M. incognita.

Highlights

RESUMO: Problemas causados pelos nematoides-das-galhas, pertencentes ao gênero Meloidogyne podem ser controlados com a introdução de genes de resistência em cultivares comerciais de tomateiro
Brazil is one of the main industrial tomato producing countries, accounting for 5% of world production (WPTC, 2018), and the state of Goiás is responsible for the largest production in the country, about 80%
Expression of the Mi gene is heat sensitive and its effect can be lost when the soil temperature surpasses 28 °C, allowing the nematode to reproduce in the plant root, even if it contains the resistance gene (DROPKIN, 1969)

Summary

Introduction

RESUMO: Problemas causados pelos nematoides-das-galhas, pertencentes ao gênero Meloidogyne podem ser controlados com a introdução de genes de resistência em cultivares comerciais de tomateiro. Suplantação de resistência do gene Mi por nematoide-das-galhas em tomate industrial no Cerrado de Goiás, Brasil The root-knot nematodes, caused by genus Meloidogyne, is among the main phytosanitary problems of industrial tomatoes, frequently reported as host of the main species of root-knot nematodes present in Brazil, which can cause up to 85% losses in productivity (FERRAZ & CHURATA-MASCA, 1983).

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