Abstract Detail

Bryology and Lichenology

Patel, Nikisha [1], Medina, Rafael [1], Johnson, Matt [1], Goffinet, Bernard [1].

Autopolyploidy contributes to cryptic speciation in mosses.

Whole genome duplication is a process critical to catalyzing change in the evolution of all plants. By resulting in meiotic incompatibility among sets of homologous chromosomes, polyploidy may facilitate reproductive isolation and the potential for speciation. All major lineages of land plants except hornworts include paleopolyploidization in their history and polyploids may constitute as much as 24% of all extant angiosperm lineages. The prevalence and significance of autopolyploidy in bryophytes is less understood. Karyotypes are valuable datapoints for assessing whole genome duplication in bryophytes. Using Reinhard M. Fritsch’s 1990 compendium of bryophyte karyotypes entitled Index to Bryophyte Chromosome Counts, with augmentations from karyological studies published since, we have quantified the prevalence of neopolyploidy among ~1500 extant morphological species of mosses. We assessed the phylogenetic distribution of karyological data, sought for trends in intraspecific ploidy variation in terms of life history traits, and habitat. At least two ploidy levels were recorded from 28% of species, a percentage higher than in angiosperms, and potentially increasing current taxonomic diversity of mosses to nearly 20,000 species. Many species, such as in Tortula, Physcomitrium, Amblystegium, and Sphagnum, comprise a polyploid series. Intensive sampling in many such species have revealed polyploid complexes warranting taxonomic revision to accommodate and describe cryptic species. Indeed, here 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. While the immediate consequence of autopolyploidy remain poorly understood, or even unexplored in bryophytes, we are revising the effect of polyploidy on sexual systems, and providing a framework for understanding the role of polyploidy in the evolution of sex in mosses.  

1 -
2 - Augustana College, Biology, 639 38th Street , Rock Island, Illinois, Illinois, 61201, USA
3 - Texas Tech University, Biological Sciences, 2901 Main Street, Ms3131, Lubbock, TX, 79409, United States
4 - University Of Connecticut, Department Of Ecology & Evolutionary Biology, 75 N. Eagleville Road, U-3043, Storrs, CT, 06269, United States


Presentation Type: Oral Paper
Session: BL1, Bryology/Lichenology AJ Sharp Session
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 10:45 AM
Number: BL1004
Abstract ID:738
Candidate for Awards:A. J. Sharp Award

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