Allozyme analysis of cryptic species in the Asplenium nidus complex from West Java, Indonesia

Abstract

In various fern species, a large amount of rbcL sequence variation has been reported, and it is possible that these species contain several reproductively isolated cryptic species. In our previous study on Asplenium nidus L., it was suggested that the plants growing in Mt. Halimun National Park, West Java, Indonesia, consist of several cryptic species based on the results of crossing experiments among rbcL sequence types. In this study, we examined allozyme polymorphisms of five rbcL sequence types found in West Java in order to test the hypothesis that the assemblages of A. nidus delimited based on the rbcL sequences are separate Mendelian populations and gene flow is disrupted by reproductive isolation from one another. The calculated fixation indices suggested that the individuals in each rbcL type are randomly crossing at least in the investigated localities. Nevertheless, these rbcL-based assemblages were genetically differentiated in allozymes that are encoded in their nuclear genomes, and it is also suggested that gene flow is disrupted even between sympatrically distributed pairs of rbcL sequence types. Therefore, our findings support the view that the five rbcL sequence types in West Java are potential cryptic species.