Clonality, local population structure and gametophyte sex ratios in cryptic species of the Sphagnum magellanicum complex

• DOI: 10.1093/aob/mcad077
• Publication Date: 2023-07-07T10:59:46Z
• Authors: A Jonathan Shaw; Aaron M Duffy; Marta Nieto-Lugilde; Blanka Aguero; Scott Schuette; Sean Robinson; James Loveland; Karen A Hicks; David Weston; Bryan Piatkowski; Max Kolton; Joel E Koska; Adam L Healey
• Keywords: Sphagnum; Species complex; Apomixis

Abstract Background and Aims Sphagnum (peatmoss) comprises a moss (Bryophyta) clade with ~300–500 species. The genus has unparalleled ecological importance because Sphagnum-dominated peatlands store almost third of the terrestrial carbon pool peatmosses engineer formation microtopography peatlands. Genomic resources for are being actively expanded, but many aspects their biology still poorly known. Among these degree to which species reproduce asexually, relative frequencies male female gametophytes in haploid-dominant plants. We assess clonality gametophyte sex ratios test hypotheses about local-scale distribution clones sexes four North American S. magellanicum complex. These difficult distinguish morphologically very closely related. also microbial communities associated host plant at two sites. Methods Four hundred five samples species, representing 57 populations, were subjected restriction site-associated DNA sequencing (RADseq). Analyses population structure based on molecular data utilized both phylogenetic phenetic approaches. Multi-locus genotypes (genets) identified using RADseq data. Sexes sampled ramets determined approach that coverage loci chromosomes after method was validated sample plants expressed phenotypically. Sex estimated each populations within Difference fitness between genets as numbers genet comprised. Degrees [numbers genets/numbers (samples)] among sites, estimated. Sphagnum-associated assessed sites relation sex. Key Results All appear engage mixture sexual asexual (clonal) reproduction. A single ramet represents most eight dsumbers ansd text etected some genets. Only one is represented by multiple populations; all other restricted population. Within individual spatially clustered, suggesting limited dispersal even male-biased diabolicum female-biased three although significantly so only divinum. Neither nor males/females differ levels clonal propagation. At St Regis Lake (NY) Franklin Bog (VT), community composition strongly differentiated differences not detected. divinum, however, harboured times number taxa males. Conclusions exhibit similar reproductive patterns result from spatial clonally replicated suggest fall so-called phalanx patterns, where abut another do extensively mix fragmentation, guerrilla extensive fragmentation greater mixing different Although bryophytes often female-biased, biases occur this complex related association far diversity ratio, suggests additional research determine if consistently correlated differing ratio biases.