Materials and Methods
Population samplingWe sampled a total of 200 individuals of Avicennia marina from 19
sites of the Arabian Peninsula coasts (var. marina , N = 190), and
one site from Australia (var. australasica , N = 10) to be used as
outgroup (Fig. 1A; Table S1, Supplementary Information). Leaf tissue was
collected from trees separated by at least 20 meters, and preserved in
silica beads for up to ten days before extraction. Geographic
coordinates for each one of the trees were recorded. Genomic DNA was
extracted from ground leaf tissue using the DNeasy 96 plant kit (Qiagen,
Valencia, CA) according to the manufacturer’s protocol. All sampling
activities were conducted in compliance with the Environment Agency Abu
Dhabi, and the Oman Ministry of Environment and Climate Affairs.