滇南桫椤的系统位置:来自叶绿体trnL内含子和DNA trnL-F间隔区序列的证据

为了探讨滇南桫椤Alsophilaaustroyunnanensis的系统位置 ,我们对该植物与中华桫椤Alsophilacostularis的叶绿体DNAtrnL内含子和trnL F间隔区序列进行PCR扩增和序列测定。滇南桫椤的trnL内含子、trnL F间隔区序列的长度分别为 5 70bp ,36 2bp ;中华桫椤的trnL内含子、trnL F间隔区序列的长度分别为 5 72bp ,36 1bp。结合已经发表的其他桫椤科植物的相应序列进行系统发育分析 ,用简约法和邻接法构建的系统发育树基本一致。结果表明 :1)所分析的桫椤科植物构成一个单系群 ;2 )滇南桫椤与Gymnosphaerapodophylla、Gymnosphaerapectinata、Gymnosphaerapseudogigantea、Gymnosphaeratinganensis、Gymnosphaeragigantea关系较近 ,聚成一支系 ;3)中华桫椤与Cyatheatsangii、Alsophilaspinulosa关系较近 ,聚成一支系。本文系统发育分析的结果支持将滇南桫椤归入黑桫椤属Gymnosphaera。     

4种桫椤初生叶的形态发育及其系统学意义

用腐叶土培养海南白桫椤(Sphaeropteris hainanensis)、阴生桫椤(Alsophila latebrosa)、刺桫椤(A.spinulosa)和滇南桫椤(A.austroyunnanensis)的孢子,获得有性生殖苗.观察并比较了幼孢子体最初4枚叶片形态发生的详细过程,据此讨论了其种属划分的合理性及相关的系统学意义.     

中国桫椤科植物新分类群

桫椤科ＦａｍｉｌｙＣｙａｔｈｅａｃｅａｅＫａｕｌｆｕｓｓ .桫椤属木桫椤属Ｇｅｎ .ＡｌｓｏｐｈｉｌａＲ .Ｂｒｏｗｎ桫椤组Ｓｅｃｔ.Ａｌｓｏｐｈｉｌａｉｃ .微刺桫椤新种Ａｌｓｏｐｈｉｌａｖｅｒｒｕｃｕｌｏ -ｓｐｉｎｕｌａＹ .Ｋ .ＹａｎｇＹ .Ｚ .ＹｕｅｔＹ .Ｈ .Ｌｉｓｐ .ｎｏｖ .ＳｐｅｃｉｅｓｓｉｍｉｌｉｓＡｌｓｏｐｈｉｌａｃｏｓｔｕｌａｒｉＢａｋ .Ａｑｕａｄｉｆｆｅｒｔｓｔｉｐｉｔｅｖｅｒｒｕｃｕｌｏ -ｓｐｉｃｕｌａｔｉｓｐｒａｅｄｉｔｉｈａｕｄｓｐｉｎｉｓ(ｉｎｅｒｍｉｂｕｓ) ,ｐｎｅｕｍａｔｏｐｈ…     

中国桫椤科植物叶绿体trnL内含子和trnL-trnF基因间隔区序列的系统发育分析

运用对PCR产物直接测序和克隆后测序的方法测定了蚌壳蕨科1种和桫椤科11种(其中桫椤分别测定19株：小羽桫椤测定2株)植物的叶绿体trnL基因内含子和trnL-trnF基因间隔区序列。12种植物相应的长度介亍l004-l082之间,A T平均含量60．9％,G C平均含量39．1％。计算了不同种间以及种内不同个体间序列的碱基差别(转换值／颠换值)和Kimura遗传距离。序列数据经排列后分别进行最简约法、最大似然法和邻接法分析,结果显示：(1)白桫椤、海南白桫椤和大羽桫椤构成的分支最早和该科内其余植物组成的另一分支分歧,而后者又进一步分为刃个亚分支,分别和桫椤亚属、黑桫椤亚属对应,支持夏群的分类处理：(2)大桫椤～狭羽桫椤～毛轴桫椤～篦齿桫椤、多羽桫椤一白桫椤～海南白桫椤以及小羽桫椤一桫椤各自构成独立、自然的末端分支,再参照分支内植物间的遗传距蔼取值,建议将此3个末端分支依次归并为3种：大桫椤、白桫椤和桫椤;(3)白桫椤属在科内处于基部位置,桫椤属奇桫椤亚属和黑桫椤亚属为衍生分支,赞同Tryon关于桫椤科进化和囊群盖起源的假说。     

桫椤科三种植物配子体发育的研究

用土壤培养桫椤Alsophila spinulosa(Wall.exHook.)R.M.Tryon、中华桫椤A.costularis Baker和白桫椤Sphaeropteris brunoniana(Hook.)R.M.Tryon的孢子,利用光学显微镜对其配子体发育的各个阶段进行了观察,包括孢子形态及其萌发、原丝体发育特点、片状体和生长点的形成及分化、假根特征、精子器和颈卵器的分化及发育,以及原叶体感染真菌后的显微特征。初步讨论了桫椤科不同属(种)间的配子体发育的系统学意义和有性世代的濒危原因。     

湖南省首次发现桫椤及其区系意义

桫椤是湖南省目前发现的唯一乔木状蕨类(在我国蕨类形成高大乔木状者唯桫椤科的桫椤属和白桫椤属Sphaeropteris的部分种)。桫椤孢子体呈树状,主干一般高达1—3米(在热带或南半球有高达20米的)。叶顶生如伞状;叶柄和叶轴粗壮,深棕色,有密刺;叶片矩圆形,长     

广东阳春百涌自然保护区桫椤科植物资源调查

广东阳春百涌自然保护区属云开山脉,区内桫椤科植物资源丰富,但具体种类及其资源量并无准确资料,为此我们开展了相关野外调查和统计。调查表明,保护区内共有4种桫椤科植物,即桫椤Alsophila spinulosa、大叶黑桫椤Gymnosphaera gigantea、小黑桫椤G. metteniana和黑桫椤G. podophylla。依据保护区内桫椤科植物主要沿林道分布的特点,提出了按林道长度估算资源量的方法,据估算,保护区内有桫椤约900株,大叶黑桫椤约1.5万株,小黑桫椤约320株,黑桫椤约4500株。阳春百涌保护区是华南地区大叶黑桫椤的主要保存地。     

中国桫椤科植物的分类

本文记载了我国14种和2变种桫椤科植物及其分布。根据叶柄基部的鳞片,叶轴背面 两侧的气囊体,叶轴的颜色,囊群盖以及孢子数目等性状,把它们安排在2属2亚属中,并讨论了各类群之间可能的演化关系。     

五指山热带雨林黑桫椤种群及其所在群落特征

黑桫椤(Alsophila podophylla)属国家二级保护植物.作者在海南岛五指山山地雨林和低地雨林分别设立样地对黑桫椤种群及其所在群落进行了调查,分析了热带雨林黑桫椤种群的年龄结构、空间分布格局、数量分布以及群落结构和物种多样性.结果表明,山地雨林和低地雨林中黑桫椤种群分别为稳定型种群和增长型种群,都是完全集群分布.低地雨林的黑桫椤平均密度是山地雨林的1.7倍.土壤pH值对黑桫椤种群密度有负的影响,全磷含量对其有正的影响.山地雨林林地土壤pH值大而全磷含量低,低地雨林刚好相反.土壤酸碱度和全磷含量的差异是导致两地黑桫椤数量差异的原因之一.pH值对黑桫椤平均密度的影响效应是全磷含量的2.5倍,说明pH值是影响黑桫椤种群密度的主要因素.黑桫椤所在群落垂直结构分为3个乔木亚层、2个灌木亚层及草本层.山地雨林黑桫椤所在群落的Simpson指数和Shannon-Wiener指数分别为0.957和5.305,均匀度为0.811;低地雨林黑桫椤所在群落的Simpson指数和Shannon-Wiener指数分别为0.937和5.484,均匀度为0.804.总之,五指山山地雨林和低地雨林的黑桫椤种群年龄结构、分布格局和数量分布都有一定差异,这些差异是由生境差异造成的.热带雨林黑桫椤所在群落结构复杂,物种多样性丰富.     

广西蕨类植物新记录属——白桫椤属

报道了广西蕨类植物一新记录属——白桫椤属。该属植物以茎干直立,乔木状;叶大型,簇生于茎干顶端,叶柄平滑、有疣突或皮刺,基部鳞片的细胞一式;叶背灰白色;叶脉分叉,2～3叉;无囊群盖等为主要特征。目前该属植物在广西首次记录到白桫椤。根据原始文献及广西的标本对该种进行了描述,并提供了墨线图。     

中国节肢蕨属（水龙骨科）新资料

本文报道灰茎节肢蕨和片马节肢蕨前者是新组合的一种变种。同时也是中国和云南的新记录,后者是中国云南的一新变型。     

中国鳞毛蕨属泡鳞亚属的分类研究

鳞毛蕨属ＤｒｙｏｐｔｅｒｉｓＡｄａｎｓ．泡鳞亚属ＳｕｂｇｅｎｕｓＥｒｙｔｈｒｏｖａｒｉａｅ（Ｈ．Ｉｔｏ）Ｆｒａｓｅｒ－ＪｅｎｋｉｎｓｉｎＢｕｌ．Ｂｒ．Ｍｕｓ．Ｎａｔ．Ｈｉｓｔ．Ｂｏｔ．１４（３）：１９５．１９８６．Ｔｙｐｅ：Ｄｒｙｏｐｔｅｒｉｓｅｒｙ...     

A Classification Synopsis of the Genus Dryopteris from Yunnan

The genus Dryopteris of the Dryopteridaceae is one of the largest genera in pteridophytes, which contains about 300 species and is distributed throughout the world. There are about 200 species of this genus in China, of which at least 88 are present in Yunnan. In this paper, the author presents a classification synopsis of the genus Dryopteris. Subg. I Pycnopteris (T. Moore )Ching 1 species Subg. II. Dryopteris Sect. 1. Hirtipedes Fraser-Jenkins 19 species Sect. 2. Pandae Fraser-Jenkins 1 species Sect. 3. Fibrillosae Ching 18 species Sect. 4. Chrysocomae S. G. Lu 7 species Sect. 5. Caespitosae S.G.Lu 5 species Sect. 6. Pallidae Fraser- Jenkins 10 species Sect. 7. Marginatae Fraser-Jenkins 7 species Sect. 8. Splendentes Fraser- Jenkins 2 species Sect. 9. Purpurascentes Fraser- Jenkins 1 species Sect. 10. Nephrocystis H. I tô 3 species Subg. llI. Erythrovariae (H. I tô ) Fraser-Jenkins, emend. S.G. Lu Sect. 11. Erythrovariae 11 species Sect. 12. Variae Fraser- Jenkins 3 species A key to these groups is given and all the species are enumerated in the pres- ent paper.     

湖北省蕨类植物分布新记录（一）

武陵山区是中国植物多样性研究的热点地区之一。1988年,中国科学院植物研究所等单位完成了对该地区的第一次生物多样性普查[1],由于行政区域重新划定和交通条件限制等原因,诸多区域未涉及。近期,中南民族大学在国家科学技术部科技基础性工作专项的支持下,再次对该区域(湖北部分)进行了野外调查并采集了大量标本,以相关书籍[2-6]和近期发表的相关调查结果[7-13]为依据,鉴定出一批在湖北省区域内未曾记录的蕨类植物并将陆续予以报道。本文报道了其中的11种1变种,分别隶属于5科10属,凭证标本均存于中南民族大学植物标本馆( HSN),各种类形态特征见图1。     

叉丝壳属一新种和一新记录种

本文描述了寄生于齿叶白绢梅(Exochorda serratifolia S.More)上的叉丝壳属一新种和寄生于北五味子(Schisandra chinensis L.)上的叉丝壳属一中国新记录种,分别是Microsphaera exochordae Q.X.Lu et G.Z.L(?)和M.schizandrae Sawada。 对新种作了中文和拉丁文描述,并附有形态图,同时讨论了与相近种之间的区别。对新记录种进行了中文描述。     

The role of p21(CIP1/WAF1) in growth of epithelial cells exposed to hyperoxia

Previous studies have shown that hyperoxia inhibits proliferation and increases the expression of the tumor suppressor p53 and its downstream target, the cyclin-dependent kinase inhibitor p21(CIP1/WAF1), which inhibits proliferation in the G1 phase of the cell cycle. To determine whether growth arrest was mediated through activation of the p21-dependent G1 checkpoint, the kinetics of cell cycle movement during exposure to 95% O2 were assessed in the Mv1Lu and A549 pulmonary adenocarcinoma cell lines. Cell counts, 5-bromo-2'-deoxyuridine incorporation, and cell cycle analyses revealed that growth arrest of both cell lines occurred in S phase, with A549 cells also showing evidence of a G1 arrest. Hyperoxia increased p21 in A549 but not in Mv1Lu cells, consistent with the activation of the p21-dependent G1 checkpoint. The ability of p21 to exert the G1 arrest was confirmed by showing that hyperoxia inhibited proliferation of HCT 116 colon carcinoma cells predominantly in G1, whereas an isogenic line lacking p21 arrested in S phase. The cell cycle arrest in S phase appears to be a p21-independent process caused by a gradual reduction in the rate of DNA strand elongation. Our data reveal that hyperoxia inhibits proliferation in G1 and S phase and demonstrate that p53 and p21 retain their ability to affect G1 checkpoint control during exposure to elevated O2 levels.     

Growth arrest in G1 protects against oxygen-induced DNA damage and cell death

Although oxygen is required for normal aerobic respiration, hyperoxia (95% O(2)/5% CO(2)) damages DNA, inhibits proliferation in G1, S and G2 phases of the cell cycle, and induces necrosis. The current study examines whether growth arrest in G1 protects pulmonary epithelial cells from oxidative DNA damage and cell death. Mv1Lu pulmonary adenocarcinoma cells were chosen for studies because hyperoxia inhibits their proliferation in S and G2 phase, while they can be induced to arrest in G1 by altering culture conditions. Hyperoxia inhibited proliferation, increased intracellular redox, and rapidly reduced clonogenic survival. In contrast, Mv1Lu cells treated with transforming growth factor (TGF)-beta1, deprived of serum or grown to confluency, arrested and remained predominantly in G1 even during exposure. Growth arrest in G1 significantly enhanced clonogenic survival by 10-50-fold. Enhanced survival was not due to reduction in the intracellular redox-state of the cells, but instead was associated with reduced DNA strand breaks and p53 expression. Our findings suggest that the protective effects of G1 is mediated not simply by a reduction in intracellular ROS, but rather through an enhanced ability to limit or rapidly recognize and repair damaged DNA.     

New Taxa of Festuca L. from China

Some new taxa of the genus Festuca (Gramineae) are described from China. They are Sect. Longiglumes S.L. Lu,Sect. Muticae S.L. Lu, Sect. Sinensis S.L. Lu, Sect, Nitidulae S.L. Lu, and Festuca pubiglumis S.L. Lu, F. longiglumis S. L. Lu, F.fascinata Keng, F. mutica S.L. Lu, F. sinensis Keng, F. subalpina Chang et Skvort. ex S.L. Lu, F. chelungkingnica Chang et Skvort. exS.L. Lu. In addition, one new name F. taiwanensis S.L. Lu is included.     

中国篦齿蕨属植物（水龙骨科）一新组合种

根据叶绿体rbcL和rps4-trnS序列及叶脉类型、孢子纹饰特征等证据,栗柄水龙骨Polypodiodes microrhizoma（C.B.Clarke ex Baker）Ching属于篦齿蕨属Metapolypodium Ching的范畴,因此将其组合到篦齿蕨属MetapolypodiumChing之下更合理。文中报道了该新组合种,即栗柄篦齿蕨Metapolypodium microrhizomum（C.B.Clarke ex Baker）S.G.Lu et L.H.Yang。     

山西垣曲盆地始新世轮藻植物群

记述山西垣曲盆地河堤组任村至寨组里段轮藻化石,计１１属,１４种,２未定种,建立了一个地区性轮藻化石组合：Ｒａｓｋｙｅｌｌａｓｉｎｅｎｓｉｓ－Ｌｉｎｙｉｅｃｈａｒａｄｅｃｏｒｏｓａ－Ｓｔｅｐｈａｎｏｃｈａｒａｇｌｏｂｕｌａ组合,该组合位于中国早第三纪轮藻植物群序列中Ｏｂｔｕｓｏｃｈａｒａｊｉａｎｇｌｉｎｇｅｎｓｉｓ－Ｇｙｒｏｇｏｎａｑｉａｎｊｉａｎｇｉｃａ植物群的上部,轮藻植物群反映的地质时代始新世