基于孢子形态和分子证据探讨鳞盖蕨属(碗蕨科)系统分类

孢粉学是解决植物分类中疑难类群物种微形态分化的重要方法, 随着分子系统学的发展, 结合这两门学科的优势可以更加有效地解决疑难类群的分类学问题。鳞盖蕨属(Microlepia)是一个分类困难的疑难类群, 采用孢粉学与分子系统学一一对应的方法, 以及居群取样方式, 选取280份样本, 联合4个叶绿体片段(rbcL、trnL-F、psbA-trnH和rps4), 采用最大似然法和贝叶斯法构建该属的系统发生关系, 在此基础上对凭证标本中100份材料的孢子进行观察和分析。综合分子系统学和孢粉学的研究结果, 得出结论: (1) 在形态学研究中广泛被接受的15个物种得到了单系支持, 并厘清了分类困难的复合群; (2) 发现边缘鳞盖蕨(M. marginata)可能存在隐性种; (3) 建议恢复过去归并处理为异名的瑶山鳞盖蕨(M. yaoshanica)、罗浮鳞盖蕨(M. lofoushanensis)、四川鳞盖蕨(M. szechuanica)以及滇西鳞盖蕨(M. subspeluncae); (4) 提出鳞盖蕨属可能存在杂交现象; (5) 提出鳞盖蕨属完整的属下分类建议。     

安徽省苔草属（灰帽苔草组）新分类群

本文发表了安徽省苔草属(Carex)灰帽苔草组(Sect.Praecoces Christ)6新种,1新变型,即:截喙苔草Carex truncatirostris及其变型无喙苔草f.erostris,安徽苔草C.anhuiensis,宣城苔草C.xuanchengensis,祁门苔草C.qimenensis,齐云苔草C.qiyunensis和太湖苔草C.taihuensis。     

蕨类植物孢子囊形态 I. 鳞始蕨科

孢子囊是蕨类植物的繁殖器官, 其形态在蕨类植物的分类和系统发育研究上具有重要意义。用次氯酸钠溶液处理新鲜成熟的孢子囊, 在光学显微镜下获得清晰的孢子囊图像, 系统研究了中国鳞始蕨科4属13种孢子囊的形态特征。结果表明, 鳞始蕨科孢子囊呈椭球形, 孢子囊柄由3列细胞构成, 环带类型为垂直环带。通过分析孢子囊形态数据探讨了中国鳞始蕨科属内及属间差异。结果表明, 乌蕨属(Odontosoria)、香鳞始蕨属(Osmolindsaea)、达边蕨属(Tapeinidium)和鳞始蕨属(Lindsaea)的孢子囊环带细胞数依次减少, 囊蒴体积、唇细胞数和囊壁细胞数的变化由大(多)到小(少)依次为乌蕨属、达边蕨属、香鳞始蕨属和鳞始蕨属。孢子囊属内差异最大的是阔片乌蕨(Odontosoria biflora)与乌蕨(O. chinensis)以及香鳞始蕨(Osmolindsaea odorata)与日本鳞始蕨(O. japonica); 而达边蕨属和鳞始蕨属的属内差异则很小。研究结果为揭示鳞始蕨科系统发育关系提供了形态基础, 特别是提出阔片乌蕨和乌蕨以及香鳞始蕨和日本鳞始蕨在孢子囊形态上的差异值得进一步研究。     

安徽省苔草属(指状苔草组)新分类群

本文发表了安徽省苔草属(Carex)指状苔草组(Sect.Digitatae)三新种:青阳苔草C.qingyangensis S.W.Su et S.M.Xu, 突喙苔草C.yuexiensis S.W.Suet S.M.Xu和矮秆苔草C.minuticulmis S.W.Su et S.M.Xu.     

安徽省苔藓植物名录

物种名录是一个地区生物多样性的本底性资料, 及时更新生物物种名录对生物多样性的保护及促进基础数据共享都具有重要意义。为了及时总结安徽省苔藓植物的分类学研究成果, 本文通过对文献的收集和分析, 整理出安徽省苔藓植物名录。结果显示, 安徽省共有苔藓植物95科253属777种, 其中角苔类3科3属3种, 苔类36科62属185种, 藓类56科188属589种。种数多于25的科为青藓科、细鳞苔科、丛藓科、真藓科、灰藓科、提灯藓科、白发藓科、绢藓科和蔓藓科。种数多于15的属为青藓属(Brachythecium)、真藓属(Bryum)、绢藓属(Entodon)、光萼苔属(Porella)、羽苔属(Plagiochila)、灰藓属(Hypnum)、凤尾藓属(Fissidens)、棉藓属(Plagiothecium)和耳叶苔属(Frullania)。区系成分组成上, 安徽苔藓植物以东亚成分占优势, 达到44.40%, 温带成分占31.53% (其中以北温带型最多, 占25.61%), 热带成分占18.92% (其中以热带亚洲成分最多, 达到10.30%)。安徽省共有中国特有苔藓55种, 濒危种1个, 易危种8个。安徽苔藓植物调查呈现出地区不均衡性, 建议在广泛调查的同时加强名录修订和专科专属研究, 对有条件的地区开展时空变化下物种多样性比较研究。     

巴音布鲁克天鹅湖保护区湿地植物群落研究

巴音布鲁克天鹅湖湿地植被类型在分类上属典型高寒沼泽草甸,可分为5个型。植被以湿生和水生植物为主构成,由5个层片结构组成。水沼泽植物群落的均匀度和优势度指数均高于丘状沼泽。植物群落物种重要性的大小依次为:黑穗苔草(Carex melanantha)>细刺苔草(Carex microglochn)>嵩草(Kobresia filifola)>囊状苔草(Carexvesicula)>马先蒿(Pedieularis albevti)>水麦冬(Triglochin plustre)>报春花(Primula sibirica)。在巴音布鲁克高寒沼泽草地植物群落中,水沼泽草地的鲜草产量高于丘状沼泽,分别为646.2g·m^-2和496.7g·m^-2,平均鲜草量571.5g·m^-2。群落的地下生物量较大,为13608.8 g·m^-2,0cm¹⁰cm土层中的地下生物量约占69.89%,10cm²⁰cm的地下生物量约占15.9%,20cm³⁰cm的地下生物量约占7.27%,30cm⁵⁰cm的地下生物量仅占6.94%。植物种类以莎草科植物较多(占总生物量的78.7%),大部分属于下繁性草类。物种组成简单,平方米植物种为13种,一般8种~11种。     

中国苦苣苔科的研究(二)

作者自1979年承担了中国苦苣苔科志的编写任务以后,整理了唇柱苣苦属Chirita D.Don、长蒴苣苔属Didymocarpus Wall.等属的标本,在此过程中发现了不少新分类群,其中的小花苣苔属Chiritopsis W.T.Wang及圆唇苣苔属Ggrocheilos W.T.Wang已在本刊第3期发表,本文现在发表唇柱苣苔属的新种,并将该属在我国拥有丰富种类的唇柱苣苔组Sect. Gibbosaccus Clarke作出初步分类安排。     

钱江源国家公园叶附生苔类植物的物种多样性

本文报道钱江源国家公园叶附生苔类植物4科9属19种, 较之前记录增加3科8属17种。与钱江源处于同纬度的我国其他地区相比, 钱江源叶附生苔类植物的种数仅次于西藏墨脱, 排名第二。鳞叶疣鳞苔(Cololejeunea longifolia)和尖叶薄鳞苔(Leptolejeunea subacuta)是钱江源国家公园最常见的2种叶附生苔类植物。丰富的叶附生苔类植物表明钱江源国家公园具有较合适的叶附生苔类植物生长环境, 这可能与该地区长期有效的保护密切相关。     

中国齿缘草属的研究

在编写《中国植物志》紫草科的过程中,我们系统地研究和整理了我国的齿缘草属(Eritrichium)和假鹤虱属(Hackelia),的标本,发现这两个属界线不明,难以区分,从而对它们进行了合并,选用其中较早的属名一齿缘草属(Eritrichium)作为合并后的属名。本文拟对合并后的齿缘草属(Eritrichium)的范围以及国产该属植物的系统和新分类群作一报道。     

中国东北产二柱苔草组(sect.Arenariae)新苔草

中国东北系包括黑龙江、吉林和辽宁省,二柱苔草组(Carex sect.Arenariae Kunth)在该地区种类虽不多,分布却甚普遍。关于东北苔草属的专著《东北草本植物志》(第十一卷,1976,科学出版社)汇总了4个种1个变种,其中山林苔草(Carex yamalsudana Ohwi),因未见到标本,尚待研究外,根据初步验查研究,东北产本组苔草,有6个种l个变型,其中包括两个新种。这2个新种与其他种的主要区别,见下列检索表。     

长白山区苔草泥炭沼泽植物物种多样性

本研究以长白山区典型苔草沼泽为对象,分析了密丛型苔草(瘤囊苔草、乌拉草)沼泽和疏丛型苔草(毛苔草)沼泽的植物物种多样性.结果 表明:3种苔草沼泽植物群落共有83个物种,隶属于36科59属.其中,乌拉草沼泽有71个物种,瘤囊苔草沼泽有61个物种,毛苔草沼泽有26个物种.密丛型苔草沼泽植物物种数和物种丰富度明显高于疏丛型苔...     

Combining population genomics and ecological niche modeling to assess taxon limits between Carex jemtlandica and C. lepidocarpa

Carex section Ceratocystis (Cyperaceae) is a group of recently evolved plant species, in which hybridization is frequent, introgression is documented, taxonomy is complex, and morphological boundaries are vague. Within this section, a unified taxonomic treatment of the Carex jemtlandica–Carex lepidocarpa species complex does not exist, and Norway may currently be the sole country accepting species rank for both. Carex jemtlandica is mainly confined to Fennoscandia and is thus a Fennoscandian conservation responsibility. This motivated us to test the principal hypothesis that both C. jemtlandica and C. lepidocarpa represent evolutionary significant units, and that both deserve their current recognition at species level. We investigated their evolutionary distinctiveness in Norway,using restriction site-associated DNA sequencing and ecological niche modeling. Our genomic results reveal two genetic clusters, largely corresponding to C. jemtlandica and C. lepidocarpa that also remain distinct in sympatry, despite clear indications of ongoing hybridization and introgression. The ecological niche modeling suggests that they occupy different environmental niches. Jointly, our results clearly show that C. jemtlandica and C. lepidocarpa represent separately evolving entities that should qualify recognition as evolutionary significant units. Given the high level of introgression compared to other hybridizing species pairs in Carex we recommend treating C. jemtlandica as a subspecies of C. lepidocarpa.     

四种野生苔草属植物的耐寒性评价

以采自泰山的白颖苔草、披针叶苔草、青绿苔草和低矮苔草为材料,观察越冬期间田间适应性并测定低温胁迫下抗寒相关的生理指标,计算半致死温度(LT₅₀),利用模糊隶属函数法对耐寒性进行综合评价.结果表明: 4种野生苔草属植物均能安全越冬,且翌春恢复生长良好,年绿期达到260～310 d,越冬期间枯叶率为12%～95%;LT₅₀为-18.65～-11.74 ℃.随着低温胁迫的加剧,4种苔草的丙二醛(MDA)含量、游离脯氨酸(Pro)和可溶性蛋白含量总体呈先上升后下降的趋势,可溶性糖含量呈上升趋势.除披针叶苔草表现为整体呈下降趋势外,其他3种苔草的超氧化物歧化酶(SOD)活性均呈先上升后下降的趋势.耐寒性相对较弱的白颖苔草较早地积累MDA、Pro和可溶性糖.可溶性蛋白含量在低温处理后期达到最大值,且苔草的耐寒性越强其峰值越小.在低温处理初期披针叶苔草SOD活性显著高于其他3种苔草.4种苔草属植物的耐寒性强弱为:披针叶苔草>青绿苔草>低矮苔草>白颖苔草.     

薹草属少花薹草组（莎草科）小坚果形态和微形态及其分类学意义

利用扫描电镜对少花薹草组（Carex sect. Paniceae）27种及4变种（东亚14种4变种,北美13种）小坚果形态与微形态特征进行比较观察。结果表明（：1）所有材料小坚果的形状为倒卵球形和钝三棱状,组内很一致,长度为1.53～3.59 mm,同种不同居群个体差异不显著（P>0.05）。（2）表皮细胞一般为五至七边形,偶有四边形或八边形,丝柄薹草（C. rouyana）不同个体间有变异;垂周璧式样直或微波状;硅质台平,偶有凹或略凸,具1个中心体,C. filipes var. kuzakaiensis和C. filipes var. tremula中偶见2个中心体,无卫星体,这些性状种内稳定。（3）利用表皮细胞形状、硅质台凹凸情况和中心体个数对于区分近似种具有价值,如白马薹草（C. baimaensis）和线柄薹草（C. filipes）,且可以区分一些种下等级,如线柄薹草及其变种var. kuzakaiensis、var. oligostachys和var. tremula。（4）sect. Paniceae s.s.和sect. Laxiflorae小坚果形态和微形态...     

Monograph of Carex section Schiedeanae (Cyperaceae): Unexpected taxonomic and ecological diversity in a Mexican sedge clade

Carex section Schiedeanae (subg. Euthyceras) has long been thought to comprise at most five species of Mexican sedges. Our morphological studies in the field and herbarium, however, supported by more recent DNA sequencing work, demonstrate that the section is, in fact, three times as species-rich, making it one of the largest sections in Mexico. Its 15 species range from Chihuahua to Tamaulipas south to Veracruz and Oaxaca; a single species, Carex muriculata, extends into the United States. The section has unusual inflorescences with simple (except in Carex complexa), uniformly androgynous, sessile spikes, utriculiform cladoprophylls, and perigynia with a unique combination of pubescence types composed of papillae; unicellular, simple hairs; and (in many species) multicellular tubercles. We recognize five previously described species (C. muriculata,Carex perstricta,Carex schiedeana, Carex stellata, and Carex vizarronensis) and describe 10 additional species (Carex angustilepis, Carex cabralii, Carex complexa, Carex dentata, Carex gypsophila, Carex mesophila, Carex paneroi, Carex planilamina, Carex revoluta, and Carex tehuacana). We have expanded the morphological features used in the section to include particularly anther, staminate scale, and style features, and more detailed micromorphology of the perigynia, especially indumentum. In total, 13 of the 15 species recognized herein, with a total of 32 individuals, were examined for ETS and ITS for phylogenetic reconstruction. Phylogenetically, the xeric species (plus C. paneroi) form a grade leading to a clade of the more mesophytic species adapted to forest understories, plus the unique cliff dwelling C. complexa.     

人工恢复与自然恢复模式下苔草草丘生态特征比较

本研究以哈尔滨太阳岛草丘湿地为对象,对比了人工恢复与自然恢复下苔草草丘个体和种群的生态特征,并分析其与环境因子的关系.结果表明:苔草植株生长随时间呈现先增加后降低的变化趋势(5—8月),初期(5—6月)生长迅速,6月达到峰值.人工恢复和自然恢复模式下,苔草草丘个体和种群特征差异显著:自然恢复下苔草叶面积、叶宽、单株鲜重、单株干重、丘墩高度、直径、丘顶面积、丘墩表面积、丘墩体积等苔草草丘个体特征均显著高于人工恢复,人工恢复下苔草草丘密度、盖度、生物量等种群特征显著高于自然恢复,物种多样性无显著差异.土壤含水量、水深、草丘密度、丘间距离是导致2种恢复模式下苔草草丘生长差异的主要因素,自然恢复区土壤含水量、水深、间距均显著高于人工恢复区,对草丘个体的形成和发育具有促进作用,人工恢复区高移栽密度是导致草丘密度、盖度、生物量高于自然恢复区的主要因素.建议未来开展苔草草丘湿地恢复和保护时,应参考自然恢复湿地中草丘的分布特点,适当调整丘间距离(54.22～117.89 cm)和种群密度(1.9～3.1 墩·m^-2),同时采取干旱区春季适当补水措施,保持适宜的土壤含水量和水深,促进苔草草丘的生长发育和快速恢复,维持其种群长期健康稳定.     

A framework infrageneric classification of Carex (Cyperaceae) and its organizing principles

Phylogenetic studies of Carex L. (Cyperaceae) have consistently demonstrated that most subgenera and sections are para- or polyphyletic. Yet, taxonomists continue to use subgenera and sections in Carex classification. Why? The Global Carex Group (GCG) here takes the position that the historical and continued use of subgenera and sections serves to (i) organize our understanding of lineages in Carex, (ii) create an identification mechanism to break the ~2000 species of Carex into manageable groups and stimulate its study, and (iii) provide a framework to recognize morphologically diagnosable lineages within Carex. Unfortunately, the current understanding of phylogenetic relationships in Carex is not yet sufficient for a global reclassification of the genus within a Linnean infrageneric (sectional) framework. Rather than leaving Carex classification in its current state, which is misleading and confusing, we here take the intermediate steps of implementing the recently revised subgeneric classification and using a combination of informally named clades and formally named sections to reflect the current state of our knowledge. This hybrid classification framework is presented in an order corresponding to a linear arrangement of the clades on a ladderized phylogeny, largely based on the recent phylogenies published by the GCG. It organizes Carex into six subgenera, which are, in turn, subdivided into 62 formally named Linnean sections plus 49 informal groups. This framework will serve as a roadmap for research on Carex phylogeny, enabling further development of a complete reclassification by presenting relevant morphological and geographical information on clades where possible and standardizing the use of formal sectional names.     

A novel group I intron in Candida dubliniensis is homologous to a Candida albicans intron

In the present study, we determined the sequence of group I self-splicing introns found in the large ribosomal RNA subunit of Candida albicans, Candida stellatoidea and the recently-described species Candida dubliniensis. It was found that both the intron and ribosomal RNA nucleotide sequences are almost perfectly identical between different C. albicans strains as well as between C. albicans and C. stellatoidea strains. Comparisons of ribosomal RNA sequences suggest that local isolates of atypical C. albicans from individuals infected with human immunodeficiency virus can be assigned to the C. dubliniensis species. C. dubliniensis strains also harbor a group I intron in their ribosomal RNA, as observed in about 40% of C. albicans strains and all C. stellatoidea strains. This novel C. dubliniensis group I intron is identical to the C. albicans and C. stellatoidea intron, except for two widely divergent stem-loop regions. Despite these differences, the C. dubliniensis intron possesses self-splicing ability in an in vitro assay. Taken together, these data support the idea that C. albicans and C. stellatoidea should be joined together as variants of the same species while C. dubliniensis is a distinct but closely related microorganism. To our knowledge, the C. albicans and C. dubliniensis introns are the first example of a pair of homologous group I introns differing only by the presence of apparently facultative sequences in some stem-loops suspected to be involved in stabilization of tertiary structure.     

大叶铁线莲大小孢子发生及雌雄配子体发育

铁线莲属植物在花部形态和结构方面存在较大差异, 遗传背景相对复杂。因此, 在杂交育种前对其进行胚胎学研究具有重要意义。利用石蜡切片技术对大叶铁线莲(Clematis heracleifolia)大小孢子发生及雌雄配子体发育过程进行研究, 结果显示, 大叶铁线莲具雄株和两性花植株。雄花中, 雄配子体发育偶见败育现象; 而两性花中多数花粉发育异常, 形成功能性雌花。正常发育的两性花中, 雄蕊较雌蕊先发育完全。花药4室, 具腺质绒毡层, 偶见变形绒毡层。胞质分裂为同时型, 以四面体型四分体为主, 偶见左右对称型。成熟花药中, 花药壁由纤维状加厚的表皮及药室内壁构成, 花粉粒为2-细胞型, 近球状, 散沟型。子房1室, 内含少量退化胚珠及1个发育正常的胚珠, 倒生, 单珠被, 薄珠心, 蓼型胚囊, 具线形大孢子四分体及双核反足细胞。大叶铁线莲可能处于相对进化的过渡地位。在杂交育种中, 建议以雄花植株作为父本, 两性花植株仅用作母本; 在两性花花芽大小为0.5-0.8 cm时进行去雄处理。