Abstract
In recent decades coral gardening has become increasingly popular to restore degraded reef ecosystems. However, the growth and survivorship of nursery-reared outplanted corals are highly variable. Scientists are trying to identify genotypes that show signs of disease resistance and leverage these genotypes in restoring more resilient populations. In a previous study, a field disease grafting assay was conducted on nursery-reared
Acropora cervicornis
and
Acropora palmata
to quantify relative disease susceptibility. In this study, we further evaluate this field assay by investigating putative disease-causing agents and the microbiome of corals with disease-resistant phenotypes. We conducted 16S rRNA gene high-throughput sequencing on
A. cervicornis
and
A. palmata
that were grafted (inoculated) with a diseased
A. cervicornis
fragment. We found that independent of health state,
A. cervicornis
and
A. palmata
had distinct alpha and beta diversity patterns from one another and distinct dominant bacteria. In addition, despite different microbiome patterns between both inoculated coral species, the genus
Sphingomonadaceae
was significantly found in both diseased coral species. Additionally, a core bacteria member from the order Myxococcales was found at relatively higher abundances in corals with lower rates of disease development following grafting. In all, we identified
Sphingomonadaceae
as a putative coral pathogen and a bacterium from the order Myxococcales associated with corals that showed disease resistant phenotypes.
