Capsicum hypocotyls mycobiome diversity is unaffected by Phytophthora capsici inoculation

Abstract

Mycobiome of the plant-associated microbial community is important in affecting plant biological processes and plant-pathogen interactions. Most studies have emphasized on the bacterial microbiome of plants, yet mycobiome is new in this area. The aim of this work is to perform metagenomic analysis of mycobiota associated with hypocotyls of Capsicum sp. infected by Phytophthora capsici to provide better insights in understanding the pathogenicity and disease control in Capsicum sp.-P. capsici system. Internal transcribed spacer 1 (ITS1) region was used for the identification of fungi species in the metagenomic study. Monozoosporic strains of P. capsici was used to infect different Capsicum spp. (Marcato, ECU-9129, Nathalie and ECU-12831 genotypes) that were available locally in Ecuador. According to the symptoms and the hypocotyls' colonization by P. capsici in Capsicum genotypes, these were classified among resistant (ECU-9129, ECU-12831 and Nathalie) and susceptible (Marcato). Regarding the analysis, values of Shannon's diversity index, Simpson's Dominance index, and evenness were found to be 1.82–1.92, 0.75–0.77, and 0.36–0.38, respectively. Families Didymellaceae, Fomitopsidaceae, and Trichocomaceae were more abundant in the mycobiota of hypocotyls in Capsicum spp.-P. capsici pathosystem. Principal Coordinate Analysis revealed that the two principal components account for 44%, 54.1% and 37.2% of the variation for the Families, Genus and Species, respectively. This analysis suggested that the mycobiome is unaffected by P. capsici, this being exclusive to the Capsicum genotype. These findings could be important in understanding the role of the microbiome in resistant plants to oomycetes.