Abstract Detail

Bryological and Lichenological Section/ABLS

Bisang, Irene [1], Hedenas, Lars [2].

Intraspecific sex ratio variation and its predictors in mosses – the case of the wetland moss Drepanocladus lycopodioides.

Sex ratio variation is a common but unexplained phenomenon of many species with chromosomal sex determination, including many bryophytes. Expressed sex ratio variation could be related to environmental conditions in a few mosses investigated to date. However, many bryophyte populations are non-fertile during their entire life cycle and intraspecific genetic sex ratio variation remains highly unexplored in natural populations. Drepanocladus lycopodioides, a pleurocarpous wetland moss with a distribution largely confined to Western Eurasia, rarely to occasionally forms sexual organs. It belongs to the majority of bryophytes that exhibits a female bias in expressed sex ratio. We applied a novel approach to sex individual shoots irrespective of their reproductive state using a specifically designed female-targeting molecular marker. We demonstrated that the bias in sex expression corresponds to a genetic female bias in the European adult population. Here, we investigated three regional populations of D. lycopodioides in its core distribution area. We asked whether haplotype diversity (H), sex expression (SE), genetic sex ratios, and sporophyte frequency varied within and among regions, whether these characteristics were related with each other, and / or to environmental parameters. Levels of H differed among regions and were positively related to habitat patch size. H was unequally partitioned between the sexes and was associated with estimated regional sporophyte frequency. Recorded plot-wise sporophyte frequency was generally very low in all regions. Overall genetic sex ratio was female-biased in all regions. Sex expression and genetic sex ratio varied strongly within regions (SE 0 –75%), with 27% of the plots lacking sex organs and 78% of the plots one-sexed, but differences among regions were non-significant. While no sex expression occurred in habitats deeper than 25cm, genetic sex ratio was not related to the measured environmental parameters.

1 - Swedish Museum of Natural History, Department of Botany; Research Division directorate, Box 50007, Stockholm, SE-104 05 , Sweden
2 - Swedish Museum of Natural History, Department of Botany, Box 50007, Stockholm, SE-104 05, Sweden

Keywords:
Bryophyte
molecular sex marker
sex ratio
environmental factors.

Presentation Type: Oral Paper:Papers for Sections
Session: 70
Location: Salon 10/The Shaw Conference Centre
Date: Wednesday, July 29th, 2015
Time: 2:00 PM
Number: 70003
Abstract ID:100
Candidate for Awards:None