Isolation and characterization of microsatellites in iris

The Louisiana iris species complex consists of three wide-spread species (Iris fulva Ker-Gawler, I. hexagona Walter and I. brevicaulis Raf.; Viosca 1935) and a rare diploid hybrid species (I. nelsonii Rand.). While these species have relatively wide ranges (with the exception of I. nelsonii) and distinct ecological preferences, they occur sympatrically in southern Louisiana where interspecific matings have led to the pro-duction of hybrid populations (e.g. Viosca 1935; Arnold et al. 1990). Although the ecology, taxonomy and evolution of the Louisiana irises have been studied for over 50 years, direct estimates of gene flow, mating patterns and hybrid fitness in natural populations are lacking. To this end, we developed a suite of five microsatellite loci from two species of Louisiana iris, I. brevicaulis and I. fulva, that will allow us to take a paternity-based approach to the study of these phenomena in natural Iris populations. Cloning and screening procedures followed the methods of Aldrich et al. (1998). Total genomic DNA was isolated from fresh leaf tissue of a single I. brevicaulis and a single I. fulva individual using the DNeasy Plant Mini Kit (QIAGEN). The DNA was digested with MboI and size selected by excising 300–700 bp fragments from a 2 % agarose gel (QIAquick Gel Extraction Kit, QIAGEN). The size-selected DNA fragments were then ligated into the BamHI site of a lambda vector