Genome-Wide Association Studies of Amphillo germplasm resistance to Meloidogyne paranaensis

Abstract

The phytonematode Meloidogyne paranaensis is one of the main threats to coffee production. The development of Coffea arabica cultivars resistant to this pathogen is an urgent demand for coffee growers. Progenies derived from the wild germplasm Amphillo are considered potential sources of resistance to M. paranaensis, however, the mechanisms involved in this resistance have not yet been elucidated. In the present work, the resistance of different progenies derived from Amphillo was studied and molecular markers associated with resistance were identified. Through the Genomic-Wide Association, SNP markers associated with genes potentially involved in resistance control were identified. A total of 158 genotypes belonging to four progenies derived from crosses between Amphillo and Catuaí Vermelho were analyzed. These coffee plants were phenotyped for five traits related to resistance. A total of 7116 SNP markers were genotyped and, after quality filtering, 931 SNPs were selected to conduct the genome-wide association study. The mixed linear model identified 12 SNPs with significant associations with at least one of the evaluated variables and eighteen genes were mapped. The results obtained support the development of markers for assisted selection, studies on genetic inheritance, and elucidating molecular mechanisms involved in the resistance of C. arabica to M. paranaensis.