Drakaea glyptodon nuclear microsatellite and chloroplast haplotype data

Many orchids are characterized by small, patchily distributed populations.
Resolving how they persist is important for understanding the ecology of
this hyper-diverse family, many members of which are of conservation
concern. Ten populations of the common terrestrial orchid Drakaea
glyptodon from Southwest Australia were genotyped with ten nuclear and
five chloroplast SSR markers. Levels and partitioning of genetic
variation, and effective population sizes (Ne), were estimated. Spatial
genetic structure of nuclear diversity, together with chloroplast data,
are used to infer the effective number of seed parents per population. We
found high genetic diversity, Ne values that generally exceed predictions
based on the number of flowering individuals, and moderate levels of gene
flow. Two populations were founded by < 5 colonists suggesting some
populations are colonized by few seeds, with growth largely resulting from
in situ recruitment. A value of 3.65 for mp /ms indicates that pollinators
play a greater role than seed in introducing genetic diversity to
populations via gene flow. Our results highlight that D. glyptodon is
highly effective at persisting in patchily distributed populations.
However, it is important to examine how insights from this common,
widespread species transfer to species that are rare and/or occur in
fragmented landscapes.