中文摘要：

近年来对真蕨植物系统发育演化的研究引起了学术界的广泛关注,而对地史时期真蕨化石多样性变化、繁殖器官和原位孢子微细构造的探究成为了解该类群植物辐射演化历史和系统发育不可或缺的途径。我国湖北西部早侏罗世香溪组真蕨植物化石十分丰富,且具有较高的多样性,包括合囊蕨科、紫萁科、马通科、双扇蕨科及蚌壳蕨科等,共计约11属25种。近年来,对该地区真蕨植物化石研究日渐深入,并在多个领域取得了一系列重要进展。基于鄂西秭归地区保存完好的生殖器官化石标本,先后获得了合囊蕨科Marattia asiatica、马通科Phlebop-teris polypodioides、双扇蕨科Dictyophyllum nilssonii、蚌壳蕨科Coniopteris cf.bella和Coniopteris sp.等种原位孢子。利用扫描和透射电镜等手段对Marattia asiatica和Dictyophyllum nilssonii原位孢子超微结构的研究,对认识真蕨植物系统发育和演化提供了重要的微观证据。香溪组上部真蕨植物代表我国早中生代南方植物区系典型的真蕨植物生态群落,且以马通科Phlebopteris和双扇蕨科Dictyophyllum为主导分子,伴生有合囊蕨科、紫萁科和蚌壳蕨科分子,指示热带、亚热带温暖潮湿气候类型,并代表原位埋藏的泥炭沼泽生态环境。

英文摘要：

During the past decades,increased progress has been made for systematic and phylogenetic analysis of ferns and allied plants based upon morphology and molecular data leading towards a full understanding of the fern tree of life.However,fossil records of ferns in deep time provide unequivocal and indispensable evidence for exploring the diversity variation,evolutionary radiation and phylogeny of this plant group.The Lower Jurassic Hsiangchi Formation in western Hubei,China is well known for its abundant and diverse fossil ferns,including five families such as Marattiaceae,Osmundaceae,Matoniaceae,Dipteridaceae and Dicksoniaceae,as well as 25 species referred to 11 genera.Recent investigations on fossil ferns based on well preserved specimens of Hsiangchi Formation,have revealed detailed fertile structures of a diverse fossil ferns,including Marattia asiatica,Phlebopteris polypodioides,Dictyophyllum nilssonii,Coniopteris cf.bella and Coniopteris sp.In situ spore ultrastructures of Marattia asiatica,and Dictyophyllum nilssonii provide palaeobotanical evidence and positive support for the phylogeny and evolution of both fossil and living ferns.The ferns from the upper part of the Hsiangchi Formation are dominated by matoniaceous and dipteridaceous groups,and are associated with Marattiaceae,Osmundaceae and slender herbaceous Dicksoniaceae.This is a representative fern community recognized from the Southern Floristic Province in China during late Early Jurassic period,indicating a tropical to subtropical climate with warm and humid conditions,which is favorable for the peat accumulation.