古地理学报
古地理學報
고지이학보
JOURNAL OF PALAEOGEOGRAPHY
2014年
6期
861-877
,共17页
早期维管植物%华南%分支演化%辐射%多样性
早期維管植物%華南%分支縯化%輻射%多樣性
조기유관식물%화남%분지연화%복사%다양성
early vascular plant%South China%cladogenesis%radiation%diversity
尽管近年来对志留纪—早泥盆世陆生维管植物系统发育的认识取得了很大进展，但是目前对多囊蕨类、莱尼蕨类、工蕨类的界定和类群划分尚有分歧，工蕨类和石松类的姐妹群关系仍有疑问，真叶植物基部类群有待深入研究。志留纪至早泥盆世的维管植物演化可划分为2幕，即前布拉格期序幕阶段和布拉格期爆发阶段。维管植物主要分支在第1幕均处于萌芽状态，仅出现个别先驱型分子；第2幕为维管植物分支爆发式演化的主幕。在布拉格期，规则叶序、孢子叶、似叶球状结构等石松类的典型性状最早显现，真叶植物发生明显的分支分化，大型叶及其同源器官（枝叶复合体）多次独立起源，孢子囊和叶性结构的发育相关性在多个支系中趋同演化出现。古植物地理方面，在东北冈瓦纳区的华南地区，工蕨类以孢子囊螺旋排列的类型为主，真叶植物在布拉格期显示出高度的多样性和分异度；在劳俄区，工蕨类中孢子囊成列排列的类型较为丰富，真叶植物的大量出现要晚于华南地区。羊角蕨纲、拟库克逊蕨类、莱尼蕨目的分支演化可能主要发生在南劳俄和西北冈瓦纳等中、高纬度地区。工蕨类、石松类和真叶植物的分支演化和地理辐射可能遵循“走出热带”模式，它们在低纬度地区最早发生分化并快速辐射；维管植物主要分支在布拉格期的爆发式演化，主要是热带植物群革新演化的贡献。
儘管近年來對誌留紀—早泥盆世陸生維管植物繫統髮育的認識取得瞭很大進展，但是目前對多囊蕨類、萊尼蕨類、工蕨類的界定和類群劃分尚有分歧，工蕨類和石鬆類的姐妹群關繫仍有疑問，真葉植物基部類群有待深入研究。誌留紀至早泥盆世的維管植物縯化可劃分為2幕，即前佈拉格期序幕階段和佈拉格期爆髮階段。維管植物主要分支在第1幕均處于萌芽狀態，僅齣現箇彆先驅型分子；第2幕為維管植物分支爆髮式縯化的主幕。在佈拉格期，規則葉序、孢子葉、似葉毬狀結構等石鬆類的典型性狀最早顯現，真葉植物髮生明顯的分支分化，大型葉及其同源器官（枝葉複閤體）多次獨立起源，孢子囊和葉性結構的髮育相關性在多箇支繫中趨同縯化齣現。古植物地理方麵，在東北岡瓦納區的華南地區，工蕨類以孢子囊螺鏇排列的類型為主，真葉植物在佈拉格期顯示齣高度的多樣性和分異度；在勞俄區，工蕨類中孢子囊成列排列的類型較為豐富，真葉植物的大量齣現要晚于華南地區。羊角蕨綱、擬庫剋遜蕨類、萊尼蕨目的分支縯化可能主要髮生在南勞俄和西北岡瓦納等中、高緯度地區。工蕨類、石鬆類和真葉植物的分支縯化和地理輻射可能遵循“走齣熱帶”模式，它們在低緯度地區最早髮生分化併快速輻射；維管植物主要分支在佈拉格期的爆髮式縯化，主要是熱帶植物群革新縯化的貢獻。
진관근년래대지류기—조니분세륙생유관식물계통발육적인식취득료흔대진전，단시목전대다낭궐류、래니궐류、공궐류적계정화류군화분상유분기，공궐류화석송류적저매군관계잉유의문，진협식물기부류군유대심입연구。지류기지조니분세적유관식물연화가화분위2막，즉전포랍격기서막계단화포랍격기폭발계단。유관식물주요분지재제1막균처우맹아상태，부출현개별선구형분자；제2막위유관식물분지폭발식연화적주막。재포랍격기，규칙협서、포자협、사협구상결구등석송류적전형성상최조현현，진협식물발생명현적분지분화，대형협급기동원기관（지협복합체）다차독립기원，포자낭화협성결구적발육상관성재다개지계중추동연화출현。고식물지리방면，재동북강와납구적화남지구，공궐류이포자낭라선배렬적류형위주，진협식물재포랍격기현시출고도적다양성화분이도；재로아구，공궐류중포자낭성렬배렬적류형교위봉부，진협식물적대량출현요만우화남지구。양각궐강、의고극손궐류、래니궐목적분지연화가능주요발생재남로아화서북강와납등중、고위도지구。공궐류、석송류화진협식물적분지연화화지리복사가능준순“주출열대”모식，타문재저위도지구최조발생분화병쾌속복사；유관식물주요분지재포랍격기적폭발식연화，주요시열대식물군혁신연화적공헌。
Much progress has been made in the understanding of the phylogeny of Silurian-Early De-vonian vascular land plants during the past years.However,no consensus has been reached considering the delimitation and subdivision of polysporangiophytes,rhyniopsids,and zosterophyllopsids;the sister-group relationship between zosterophyllopsids and lycopsids is questioned;detailed studies of basal eu-phyllophytes are needed.The evolutionary history of the Silurian-Early Devonian vascular plants can be di-vided into two phases:The pre-Pragian prelude phase and the Early Devonian Pragian explosion (burst) phase.The first phase is characterized by initial emergences of representatives of vascular plant major clades.The second is the main phase which witnessed explosive radiation of vascular plant clades.During the Pragian, typical features of lycopsids such as regular phyllotaxy, sporophylls, and strobilus-like structures appeared;the diversification of euphyllophyte lineages occurred;megaphylls and their homolo-gous structures (branch-leaf complexes) evolved multiple times independently;and developmental inter-relationship between sporangia and leafy structures convergently established in different lineages.In South China of the northeastern Gondwanan phytogeographic unit,zosterophyllopsids were dominated by those with spirally arranged sporangia and euphyllophytes showed high diversity and disparity during the Pragian, while in the Laurussian phytogeographic unit,zosterophyllopsids with rowed sporangia were abundant and the appearance of comparable euphyllophytes occurred later than in South China.The cladogenesis of hor-neophytopsids,cooksonioids,and rhynialeans might have mainly occurred at middle and high paleolati-tudes such as southern Laurussia and northwestern Gondwana.The cladogenesis and biogeographic radia-tion of zosterophyllopsids,lycopsids,and euphyllophytes may accord with the “out of the tropics” mod-el,that is,these groups diversified and rapidly radiated earlier at low paleolatitudes;the explosion of vascular plant clades in Pragian was mainly contributed by the evolutionary novelty of tropical floras.
