ABSTRACT Introduction. A well-supported pattern among dioicous bryophytes is male rarity. However, few assessments of bryophyte sex ratios have been made across environmental gradients to assess the role of environment in shaping population sex ratios. Methods. We systematically surveyed 200 shoots from a 20 m2 urban population of Bryum argenteum, and regenerated each shoot apex until sex expression occurred (up to 315 days). Key results. Female shoots outnumbered male shoots 132 to 68, giving a sex ratio of 1.94♀: 1♂. The female bias was found in two transects in higher light environments but not in the third transect, which had a lower light level and an equal sex ratio. Female shoots took longer than male shoots to reach gametangial induction (122 vs. 60 days) and longer to produce 5 inflorescences (120 vs. 80 days). Male shoots produced an average of 10× the total number of inflorescences compared to female shoots (34 vs. 3.5 inflorescences). Despite producing more inflorescences, male plants also produced more regenerant shoots, thus contradicting the prediction that a higher prefertilisation reproductive effort in males trades off with vegetative proliferation. Female plants harboured significantly more associated microbes than male plants. Conclusions. Our results support the role of light in influencing sex ratios in this species, suggest that trade-offs between reproduction and vegetative growth may not be strong for males, and indicate a potential role of a sex-specific microbiome in influencing sex ratios.

中文翻译：

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银色苔藓 Bryum argenteum Hedw 城市种群的性别比例和性别表达。

摘要介绍。在雌雄异株的苔藓植物中，一个得到充分支持的模式是雄性罕见。然而，很少有跨环境梯度的苔藓植物性别比例评估来评估环境在塑造人口性别比例中的作用。方法。我们系统地调查了 20 平方米的 Bryum argenteum 城市种群的 200 个芽，并再生每个芽尖，直到发生性表达（最多 315 天）。关键结果。雌性枝条数量多于雄性枝条 132 比 68，性别比为 1.94♀：1♂。在较高光照环境下的两条样带中发现了女性偏见，但在第三条样带中没有发现，后者具有较低的光照水平和相等的性别比。雌性芽比雄性芽花费更长的时间来达到配子体诱导（122 天对 60 天）和更长的时间来产生 5 个花序（120 天对 80 天）。与雌性枝条相比，雄性枝条产生的花序总数平均为 10 倍（34 对 3.5 个花序）。尽管产生了更多的花序，雄性植物也产生了更多的再生芽，因此与雄性更高的受精生殖努力与营养增殖的权衡的预测相矛盾。雌性植物比雄性植物含有明显更多的相关微生物。结论。我们的研究结果支持光在影响该物种性别比例中的作用，表明繁殖和营养生长之间的权衡对雄性来说可能不强，并表明性别特异性微生物组在影响性别比例方面的潜在作用。雄性植物也产生更多的再生芽，因此与雄性更高的受精生殖努力与营养增殖的权衡相矛盾。雌性植物比雄性植物含有明显更多的相关微生物。结论。我们的研究结果支持光在影响该物种性别比例中的作用，表明繁殖和营养生长之间的权衡对雄性来说可能不强，并表明性别特异性微生物组在影响性别比例方面的潜在作用。雄性植物也产生更多的再生芽，因此与雄性更高的受精生殖努力与营养增殖的权衡相矛盾。雌性植物比雄性植物含有明显更多的相关微生物。结论。我们的研究结果支持光在影响该物种性别比例中的作用，表明繁殖和营养生长之间的权衡对雄性来说可能不强，并表明性别特异性微生物组在影响性别比例方面的潜在作用。