Premise of the study: Microsatellite markers were developed for New Zealand species of Corybas (Orchidaceae) to investigate population genetics and species delimitation.
Methods and results: From sequencing a total genomic DNA library (using Illumina MiSeq), we developed 22 microsatellite markers for C. obscurus. The di- and trinucleotide repeat loci were initially trialed on individuals representing seven Corybas taxa (C. "rimutaka," C. confusus, C. hypogaeus, C. macranthus, C. obscurus, C. trilobus, and C. walliae) and had one to eight alleles per locus. Twelve polymorphic markers were further tested on six Corybas populations from three of the seven taxa (C. obscurus, C. "rimutaka," and C. trilobus). Observed and expected heterozygosities ranged from 0-1 and 0-0.859, respectively. The utility of these 12 loci was further validated in five related Corybas species (C. hypogaeus, C. obscurus, C. vitreus, C. walliae, and C. "rimutaka"; 38 individuals) representing populations from across the North and South Islands. The average value for genetic diversity among populations (F ST) of 0.439 shows differentiation among species.
Conclusions: These markers will be useful for future studies aimed at delimiting species boundaries and examining the genetic diversity of the New Zealand Corybas species.
Keywords: Corybas; Corybas obscurus; New Zealand; Orchidaceae; microsatellite; spider orchid.