Sex determination in bryophytes: current state of the art.

This article focuses on the reproductive systems of bryophytes, a group of non-vascular land plants, emphasizing the genetic and molecular mechanisms underlying sex determination, particularly the role of U (female) and V (male) sex chromosomes in dioicous species. It highlights the dominance of the haploid gametophyte generation in bryophytes, the prevalence of dioicy (separate male and female gametophytes), and the evolutionary and ecological implications of sexual versus asexual reproduction. Recent advances in genomic technologies have enabled the characterization of sex chromosomes and identification of key sex-determining genes, especially in liverworts, offering promising tools for molecular sexing and conservation efforts. The article underscores the challenges posed by the rarity of sporophytes, biased sex ratios, and difficulties in sex identification at the vegetative stage, which hinder population genetics studies and conservation of threatened bryophyte species. It calls for further research into sex determination mechanisms across bryophyte lineages and the development of reliable molecular markers to support ecological, evolutionary, and conservation biology.