Characterization and levels of resistance in Coffea arabica × Coffea racemosa hybrids to Leucoptera coffeella

Abstract

Coffee leaf miner (CLM) Leucoptera coffeella stands out as a primary insect pest of arabica coffee plants in some regions of Brazil. Coffee breeding for CLM-resistance has used the species Coffea racemosa as gene donor for C. arabica, resulting in the development of the resistant commercial hybrid ‘Siriema AS1’. However, no previous study has characterized the resistance type, and whether there is variation in the levels expressed in progenies of ‘Siriema’ to CLM. This study aimed to characterize the type, by antixenosis or antibiosis, and the levels of resistance in segregating progenies of ‘Siriema’ plants to CLM. Experiments were conducted under laboratory conditions with artificial infestation of CLM adults in oviposition cages, where dual-choice preference assays compared each tested ‘Siriema’ progeny with the susceptible commercial cv. Arara (C. arabica). A follow-up no-choice assay evaluated five selected ‘Siriema’ progenies on the development of CLM compared to cv. Arara. As main results, ‘Siriema’ progenies were equally susceptible to CLM oviposition, and were overall stimulant relative to cv. Arara. However, there was low CLM larval survival and injury intensity on the selected ‘Siriema’ genotypes, indicating moderate levels of antibiosis-resistance, while cv. Arara and one ‘Siriema’ progeny were moderately susceptible. These findings further our understanding on the type and levels of resistance in ‘Siriema’ genotypes, aiding in the development of resistant coffee hybrids and deployment of management strategies to CLM.