Resistance to red mite in Coffea arabica genotype introgressed with Coffea racemosa genes

Abstract

The aim of this study was to assess the resistance to red mite (Oligonychus ilicis) in Coffea arabica genotypes with introgression of genes from a different species (Coffea racemosa). The experiment was conducted in a greenhouse at IAPAR (Londrina, PR, Brazil), between January 2016 and January 2017. The experiment was conducted in a completely randomized design with five genotypes, 12 replications of one plant per plot. The C. arabica cultivars IPR 100, IPR 99 and IPR 103 were evaluated as well as an F4 Arabica coffee line IAPAR H0113-40-26-10 with introgressed C. racemosa genes. Catuaí Vermelho IAC 99 cultivar, which is a pure C. arabica, was used as a susceptible control. In conditions of high natural infestation of red mite, the resistance of coffee genotypes was evaluated using a standard visual evaluation in January 2017. This evaluation was based on the percentage of leaf area with typical symptoms caused by this mite. Only one genotype, the F4 line IAPAR H0113-40-26-10 showed resistance to the red mite because present less leaf area with symptoms compared to other genotypes. The Arabica coffee cultivars IPR 99, IPR 100 and IPR 103 are as susceptible to red mite as to the susceptible control Catuaí Vermelho IAC 99.