Reaction of tomato genotypes to Meloidogyne enterolobii and effects of resistance inducing products

Abstract

Meloidogyne enterolobii is characterised by its aggressiveness and ability to reproduce on plants carrying the Mi resistance gene. However, resistant cultivars and resistance induction may be alternatives to keep the pest population at levels that do not cause economic damage. The aim of this study was to evaluate the reaction of tomato genotypes to M. enterolobii and test the efficacy of resistance inducers in four tomato genotypes. Twenty-one tomato genotypes were inoculated with 2000 eggs of M. enterolobii and evaluated after 35 days of inoculation. All genotypes tested were susceptible to M. enterolobii. Four tomato genotypes were selected and the plants were treated with Bacillus subtilis, B. licheniformis + B. subtilis + Trichoderma longibrachiatum, Acibenzolar-S-methyl (ASM) and extract of Reynoutria sachalinensis. The plants treated with B. subtilis showed higher shoot and root weight. ASM reduced the reproduction factor of M. enterolobii when applied to the genotype ‘PXT 408’. All tomato genotypes tested here are susceptible to M. enterolobii, thus confirming the ability this plant-parasitic nematode to reproduce on resistant plants with the Mi gene. The resistance inducers B. subtilis, B. licheniformis + B. subtilis + T. longibrachiatum and extract of R. sachalinensis did not influence the final nematode population in any of the genotypes used; however, ASM reduces reproduction of M. enterolobii to the genotype ‘PXT 408’.