Lepisorus inaequibasis is thought to be of hybrid origin due to its leaf shape and sporangia being intermediate between those of its putative progenitors. Subsequent molecular studies have supported its hybrid origin, but its progenitors have not been determined. Here, we performed molecular phylogenetic analysis, flow cytometry (FCM), morphological character observation, and ecological niche modelling (ENM) to elucidate the origin of L. inaequibasis. The phylogenetic trees inferred from single‐copy nuclear genes (pgiC and gapCp “short”) confirm the hybrid origin of L. inaequibasis from Lepisorus waltonii and Lepisorus jakonensis. Chloroplast DNA (cpDNA) phylogeny indicates that L. jakonensis is the maternal progenitor. All populations of L. inaequibasis share a single cpDNA haplotype identical to the lineage of L. jakonensis in the central Himalayas; thus, we hypothesize that L. inaequibasis originated in the central Himalaya region and dispersed to east Himalaya and Hengduan Mountain regions. Based on FCM, L. inaequibasis is tetraploid, while its progenitors are diploid. Principal component analysis of rhizome scales and observations of sporangial annuli indicated a high degree of morphological similarity between L. inaequibasis and its paternal progenitor species, L. waltonii. The ENM results showed that L. inaequibasis has a relatively high niche identity value with L. waltonii. Therefore, we conclude that L. inaequibasis is an allotetraploid that originated through hybridization between the diploid species L. waltonii and L. jakonensis. This allotetraploid species shows clear paternal bias in both its morphological characters and its ecological niche.

中文翻译：

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异源四倍体不定短鞭小夜蛾（Polypodiaceae）的起源以及其形态和非生物生态位的父系偏见

因其叶形和孢子囊介于其推定的祖细胞之间，因此认为其为不育的Lepisorus inaequibasis。随后的分子研究支持其杂种起源，但尚未确定其祖细胞。在这里，我们进行了分子系统发育分析，流式细胞术（FCM），形态特征观察，以及生态位模型（ENM）阐明的起源L. inaequibasis。从推断进化树单拷贝核基因（PGIC和gapCp “短”）确认的杂种起源L. inaequibasis从瓦韦waltonii和瓦韦jakonensis。叶绿体DNA（cpDNA）系统发育表明，Jakonensis是母体祖先。稻瘟病菌的所有种群都具有一个与喜马拉雅中部的雅各克氏菌谱系相同的单一cpDNA单倍型。因此，我们假设L. inaequibasis起源于喜马拉雅山中部地区，并散布到喜马拉雅山东部和横断山区。基于FCM，不饱和乳杆菌是四倍体，而其祖细胞是二倍体。根茎鳞片的主成分分析和孢子囊环的观察表明，不饱和乳杆菌与其父本L. waltonii在形态上高度相似。该ENM结果表明，L. inaequibasis具有比较高的利基标识值L. waltonii。因此，我们得出的结论是，inaequibasis是一种异源四倍体，它是通过二倍体种waltonii和jakonensis杂交产生的。该异源四倍体物种在其形态特征和生态位方面均表现出明显的父本偏见。