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Articles
Published: 2021-06-30

Karyotypic diversity and cryptic speciation: Have we vastly underestimated moss species diversity?

Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd. Storrs, CT, 06269
Biodiversidad, Ecología y Evolución, Universidad Complutense de Madrid, C/ José Antonio Novais, 12, 28040 Madrid, Spain
Department of Biological Sciences, Texas Tech University 2901 Main Street, Lubbock TX 79404
Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd. Storrs, CT, 06269
Bryophyta polyploidy autopolyploidy diversity taxonomy

Abstract

Karyotypic diversity is critical to catalyzing change in the evolution of all plants. By resulting in meiotic incompatibility among sets of homologous chromosomes, polyploidy and aneuploidy may facilitate reproductive isolation and the potential for speciation. Across plants, karyotypic variants in the form of allopolyploids receive greater taxonomic attention relative to autopolyploids and aneuploids. In particular, the prevalence and significance of autopolyploidy and aneuploidy in bryophytes is little understood. Using Fritsch’s 1991 compendium of bryophyte karyotypes with augmentation from karyological studies published since, we have quantified the prevalence of karyotypic variants among ~1500 extant morphological species of mosses. We assessed the phylogenetic distribution of karyological data, the frequency of autopolyploidy and aneuploidy, and the methodological correlates with karyotypic diversity. At least two ploidy levels were recorded from 17% of species potentially increasing current taxonomic diversity of mosses to over 15,000 species. We find that for a given species, the number of unique karyotypes recorded is correlated with the number of populations sampled. The evidence suggests that cytological diversity likely underlies yet undescribed species diversity in mosses, and that intensive karyological sampling is a needed tool for its discovery.

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