毛乌素沙地植物多样性保护防沙治沙示范

以榆林红石峡沙地植物群落为研究对象,采用群落生态学的调查方法,对群落结构特征、植物生活型、植物多样性分析研究,为毛乌素沙地植物多样性保护防沙治沙提供科学依据.结果表明:榆林红石峡沙地植物种类丰富,包括3门5纲29目62科168属252种,其中蕨类植物门1纲1目1科1属2种;裸子植物门2纲2目3科5属14种;被子植物门2...     

白粉菌属级分类系统的讨论

白粉菌是子囊菌门 Ascomycota 白粉菌目 Erysiphales 真菌的总称,包括 1 科 15 属(新分类系统)约 650 种(Takamatsu, 2002)。白粉菌是植物绝对寄生菌。世界上已经报道的寄主有 9 838 种被子植物。在 9 838 种被子植物中,有 9176 种是双子叶植物,662 种单子叶植物,在 662 种单子     

中国樟科物种编目:问题和展望

<正>樟科(Lauraceae)隶属于被子植物木兰亚纲(Magnoliidae)木兰超目(Magnolianae)樟目(Laurales)(RevealChase,2011)。该科的化石记录可追溯至白垩纪中期,现存50属2,500–3,000种,泛热带分布(李捷和李锡文,2004),是被子植物分类中最困难的科之一(Paton et al.,2008)。根据分子系统学研究(Chanderbali et al.,2001;RohwerRudolph,2005),樟科包含最基部的Hypodaphnis Stapf分支、厚壳桂属(Cryptocarya R.Br.)群分支、檬果樟属(Caryodaphnopsis Airy Shaw)–新樟属(Neocinnamomum     

木兰藤科系统位置评述

木兰藤科(Austrobaileyaceae)含1属2种,是系统学上最孤立的科之一。其花粉类似于最古老的被子植物化石之一:晚白垩世的棒纹粉。最新的分子系统发育研究结果表明,木兰藤科是现存被子植物的基部类群之一,其对于被子植物的起源与早期进化的研究具有重要价值。被子植物(有花植物)的起源和辐射一直是植物学家关注的热点。有关木兰藤科的系统位置一直存在争议。本文对该科系统位置的研究历史与现状进行评述。     

被子植物APG分类系统评论

随着植物分子系统学的兴起,被子植物系统发育研究取得了举世瞩目的进展。被子植物系统发育组提出了基于DNA证据的被子植物在目、科分类阶元上的分类系统,简称APG系统。本文简要概括了APG系统的主要成就:(1)验证了被子植物分类系统的可重复性和可预言性;(2)解决了一些依据形态学性状未能确定的类群的系统位置;(3)证明了将被子植物一级分类分为双子叶植物和单子叶植物的不自然性;(4)证实了单沟花粉和三沟花粉在被子植物高级分类单元划分中的重要性;(5)发现雄蕊的向心发育和离心发育在多雄蕊类群中是多次发生的,不应作为划分纲或亚纲的重要依据;(6)支持基于形态学(广义)性状划分的大多数科是自然的;(7)将一些长期认为自然的科四分五裂。同时,我们指出了尚需深入研究的几个问题:(1)如何将以分子数据建立的系统和以综合形态学证据建立的系统相协调;(2)依据APG系统的研究结果需要创立新的形态演化理论;(3)只以"单系群"作为划分科、目的依据值得商榷;(4)APG系统中一些目的分类没有可信的形态学共衍征;(5)依据APG系统需要做出一个自然系统的目、科检索表和目、科的特征集要。此外,我们对以亚洲,特别是东亚为分布中心的一些类群的系统关系或分类等级提出建议,包括八角科、芒苞草科、水青树科、火筒树科、马尾树科、七叶树科、槭树科、伯乐树科应独立为科,山茱萸科(广义)应分为山茱萸科(狭义)和蓝果树科(广义)。     

菊花的进化

菊亚纲的菊目是被子植物门双子叶植物纲中最进化的一个目。菊科非常年轻,化石仅出现于第三纪的渐新世。由于它在繁殖结构和适应性方面具有很多优越性,如:生命周期短.发达的地下茎,花和花序构造高度适应虫媒异花传粉,果实特性有利于借助动物和风力传播等,使得菊科植物尽管很少成为森林树种,也很少     

试论木兰植物门的一级分类——一个被子植物八纲系统的新方案

近年来,植物比较形态学、化学分类学、古植物学、分支系统学和分子系统学研究的结果,对传统 上将被子植物分为单子叶和双子叶植物两大群的一级分类提出了挑战,怀疑这样的分类是否能反映被 子植物内部的主要进化趋势。我们认为分类必须建立在谱系关系上,以表示其自然系统。在早白垩世 结束之前,其中有一次被子植物大辐射,有8条主传代线似已明显出现。根据林奈阶层系统,我们以 “纲”级来命名这些传代线以显示被子植物内部的主要进化趋向,虽然某些“纲”是并系类群。我们不否 认,我们是进化系统学家,并系类群可以作为一个自然类群来命名而被接受。这8个纲列述如下:木兰 纲、樟纲、胡椒纲、石竹纲、百合纲、毛茛纲、金缕梅纲、蔷薇纲。在本文中,每个纲只举其所包含的主要的科,至于纲间的系统关系,以及纲内的分类系统,有待进一步研究 。     

内蒙古阿尔山地区大型真菌物种多样性研究

在内蒙古阿尔山地区采集到大型真菌标本205种,隶属于2门5纲13目44科89属,其中子囊菌门3纲3目4科4属7种,担子菌门2纲10目40科85属198种。记载2个中国新记录种,即黄盖环柄菇(拟)Lepi-ota flava Beeli和亚托丝盖伞(拟)Inocybe subvolvata Hongo,73个内蒙古新记录种。凭证标本保存于吉林农业大学菌物标本馆(HMJAU)。     

宝天曼落叶阔叶林土壤细菌多样性

土壤微生物在森林生态系统中起着重要作用。高通量测序方法的出现为进一步认识土壤微生物提供了契机。本文利用Illumina Miseq高通量测序技术对宝天曼森林土壤的细菌多样性进行了初步研究。结果显示: 在31个采样点内, 随着采样点增加, 检测出不同分类水平的土壤细菌类群也在增多, 当采样点达到31个时, 检测出的土壤细菌类群达到45门163纲319目495科785属和42,632个OTU; 31个土壤样品中所检测出的细菌类群平均有34.2门114.7纲215.2目323.7科446.6属5,924.7个OTU, 其中门、纲、目分类水平上的优势类群(所占比例)分别为变形菌门(Proteobacteria)(38.30%)、α-变形菌纲(α-Proteobacteria)(18.08%)、根瘤菌目(Rhizobiales)(10.62%)。这些初步研究结果表明在一定程度上宝天曼森林土壤有较高的细菌多样性水平, 为进一步认识森林土壤细菌多样性与植物多样性关系等奠定了基础。     

现存被子植物原始类群及其植物地理学研究

在吸取各学派对被子植物原始类群界定的基础上,根据八纲系统,提出被子植物原始类群有60科的新见解,并以分子系统学提出的狭义的基部类群32科为对比,进行了植物地理学研究。以科为性状,以Takhtajan 划分的世界植物区系的“区”为OTU,UPGMA分析显示：(1)东亚区确是一个十分特殊的区,它既与北美东、西部(北美大西洋区、马德雷区)有密切关系,但更接近印度支那区;(2)环太平洋的4个地区集中了较多的原始被子植物的科,它们是东亚地区,北美东部和西部地区,部分热带亚洲、澳大利亚东部和西南太平洋岛屿地区,中、南美热带地区。这种分布格局显然和被子植物起源地与扩散以及太平洋的形成历史有关。     

Synopsis of a new “polyphyletic-polychronic-polytopic” system of the angiosperms

This work is continuation of two papers published by the present authors in 1998, in which our basic viewpoints on the phylogeny and evolution of angiosperms were presented. In this paper, a new outline of classification of the Magnoliophyta (angiosperms) is proposed. The Magnoliophyta are divided into 8 classes, 40 subclasses, 202 orders and 572 families. Among them, 22 new subclasses (Annonidae, Illiciidae, Ceratophyllidae, Lauridae, Calycanthidae, Chloranthidae, Aristolochiidae, Polygonidae, Plumbaginidae, Bromeliidae, Zingiberidae, Juncidae, Poaidae, Paeoniidae, Papaveridae, Trochodendridae, Betulidae, Malvidae, Ericidae, Myrtidae, Rutidae, Geraniidae) and 6 new orders (Degeneriales, Aizoales, Platanales, Dipentodontales, Meliosmales, Balanitales) are circumscribed. The number of genera and speciesin the families and each family’s geographical distribution are given.     

Natural taxonomic categories of angiosperms obey Benford's law,but artificial ones do not

Benford's phenomenological law gives the expected frequencies of the first significant digit (i.e., the leftmost non-zero digit) of any given series of numbers. According to this law, the frequency of 1 is higher than that of 2; this in turn appears more often than 3, and so on decreasing until 9. Similarly, Benford's law can also be applied to the first two significant digits (i.e., from 10 to 99), and so on. We applied Benford's law to sets of taxonomic data sets consisting of the number of taxa included in taxa of higher rank. We chose the angiosperms (Magnoliophyta) as a model case, because they are very diverse, are monophyletic, and a consensus on taxonomy of orders and families has been achieved (classification APG III), and we used as sets of data the number of species, genera, families, and orders. Only the number of species per family and per order are Benford's sets, but the remaining data sets do not obey Benford. Furthermore, in the case of the analysis of the first two significant digits of species per genus, the deviation from Benford was very large, but they fit to a power law. Given that the conformity to Benford's law is fulfilled for ‘natural' taxonomic categories of angiosperms (i.e., species and family), but not for those with more artificiality (genus), we speculate, ‘the more natural, the more Benford'.     

Phylogenetic tree of vascular plants reveals the origins of aquatic angiosperms

Although aquatic plants are discussed as a unified biological group, they are phylogenetically well dispersed across the angiosperms. In this study, we annotated the aquatic taxa on the tree of vascular plants, and extracted the topology of these aquatic lineages to construct the tree of aquatic angiosperms. We also reconstructed the ancestral areas of aquatic families. We found that aquatic angiosperms could be divided into two different categories: the four aquatic orders and the aquatic taxa in terrestrial orders. Aquatic lineages evolved early in the radiation of angiosperms, both in the orders Nymphaeales and Ceratophyllales and among basal monocots (Acorales and Alismatales). These aquatic orders do not have any extant terrestrial relatives. They originated from aquatic habitats during the Early Cretaceous. Asia would have been one of the centers for early diversification of aquatic angiosperms. The aquatic families within terrestrial orders may originate from other areas besides Asia, such as America or Australia. The lineages leading to extant angiosperms diversified early in underexploited freshwater habitats. The four extant aquatic orders were relicts of an early radiation of angiosperm in aquatic environments. Their extinct ancestors might be aquatic early angiosperms.     

Organization of the root apical meristem in angiosperms

Although flowers, leaves, and stems of the angiosperms have understandably received more attention than roots, the growing root tips, or root apical meristems (RAMs), are organs that could provide insight into angiosperm evolution. We studied RAM organization across a broad spectrum of angiosperms (45 orders and 132 families of basal angiosperms, monocots, and eudicots) to characterize angiosperm RAMs and cortex development related to RAMs. Types of RAM organization in root tips of flowering plants include open RAMs without boundaries between some tissues in the growing tip and closed RAMs with distinct boundaries between apical regions. Epidermis origin is associated with the cortex in some basal angiosperms and monocots and with the lateral rootcap in eudicots and other basal angiosperms. In most angiosperm RAMs, initials for the central region of the rootcap, or columella, are distinct from the lateral rootcap and its initials. Slightly more angiosperm families have exclusively closed RAMs than exclusively open RAMs, but many families have representatives with both open and closed RAMs. Root tips with open RAMs are generally found in angiosperm families considered sister to other families; certain open RAMs may be ancestral in angiosperms.     

Taxonomy and Biogeography of Apomixis in Angiosperms and Associated Biodiversity Characteristics

Apomixis in angiosperms is asexual reproduction from seed. Its importance to angiospermous evolution and biodiversity has been difficult to assess mainly because of insufficient taxonomic documentation. Thus, we assembled literature reporting apomixis occurrences among angiosperms and transferred the information to an internet database (http://www.apomixis.uni-goettingen.de). We then searched for correlations between apomixis occurrences and well-established measures of taxonomic diversity and biogeography. Apomixis was found to be taxonomically widespread with no clear tendency to specific groups and to occur with sexuality at all taxonomic levels. Adventitious embryony was the most frequent form (148 genera) followed by apospory (110) and diplospory (68). All three forms are phylogenetically scattered, but this scattering is strongly associated with measures of biodiversity. Across apomictic-containing orders and families, numbers of apomict-containing genera were positively correlated with total numbers of genera. In general, apomict-containing orders, families, and subfamilies of Asteraceae, Poaceae, and Orchidaceae were larger, i.e., they possessed more families or genera, than non-apomict-containing orders, families or subfamilies. Furthermore, many apomict-containing genera were found to be highly cosmopolitan. In this respect, 62% occupy multiple geographic zones. Numbers of genera containing sporophytic or gametophytic apomicts decreased from the tropics to the arctic, a trend that parallels general biodiversity. While angiosperms appear to be predisposed to shift from sex to apomixis, there is also evidence of reversions to sexuality. Such reversions may result from genetic or epigenetic destabilization events accompanying hybridization, polyploidy, or other cytogenetic alterations. Because of increased within-plant genetic and genomic heterogeneity, range expansions and diversifications at the species and genus levels may occur more rapidly upon reversion to sexuality. The significantly-enriched representations of apomicts among highly diverse and geographically-extensive taxa, from genera to orders, support this conclusion.     

Relationships of the Gymnosperms and Angiosperms Estimated on the Basis of Data Obtained by Biochemical Methods

The phylogenetic relationships of gymnospermous and angiospermous plants were studied. To this end, 13 antisera to seed proteins of plant taxa representing all the four classes of the gymnosperms were obtained. The antigens used in immunochemical reactions with these antisera included the proteins of 134 seed samples representing 91 families from all the 11 subclasses of dicotyledons and 64 seed samples representing 33 families from five out of six classes of monocotyledons (according to Takhtajan, 1996). Immunochemical analysis was performed by the methods of double immunodiffusion in agar gel (two variants) and immunoelectroblotting. In addition, some samples of seed proteins were analyzed for amino acid composition. The results corroborate the concept that the seed plants are a monophyletic taxon. The angiosperms apparently originated from a progymnospermous ancestor or branched from the main stem of gymnosperms prior to its division into the recent phyla. No common ancestor of all subclasses of the angiosperms has been identified.     

Identification,expression, and taxonomic distribution of alternative oxidases in non-angiosperm plants

Alternative oxidase (AOX) is a terminal ubiquinol oxidase present in the respiratory chain of all angiosperms investigated to date, but AOX distribution in other members of the Viridiplantae is less clear. We assessed the taxonomic distribution of AOX using bioinformatics. Multiple sequence alignments compared AOX proteins and examined amino acid residues involved in AOX catalytic function and post-translational regulation. Novel AOX sequences were found in both Chlorophytes and Streptophytes and we conclude that AOX is widespread in the Viridiplantae. AOX multigene families are common in non-angiosperm plants and the appearance of AOX1 and AOX2 subtypes pre-dates the divergence of the Coniferophyta and Magnoliophyta. Residues involved in AOX catalytic function are highly conserved between Chlorophytes and Streptophytes, while AOX post-translational regulation likely differs in these two lineages. We demonstrate experimentally that an AOX gene is present in the moss Physcomitrella patens and that the gene is transcribed. Our findings suggest that AOX will likely exert an influence on plant respiration and carbon metabolism in non-angiosperms such as green algae, bryophytes, liverworts, lycopods, ferns, gnetophytes, and gymnosperms and that further research in these systems is required.     

Systematics of fossil platanoids and hamamelids

The data on fossil platanoids and hamamelids are generalized, their morphological diversity and probable patterns of the establishment of the extant families Platanaceae and Hamamelidaceae are analyzed. It is shown that morphological and epidermal characters of polymorphic leaves of typical platanoid appearance were formed in the Late Albian and remained essentially invariable to the present time, indicating the morphological stasis of these leaves combined with a wide variation range. In view of association with essentially different reproductive structures, it is proposed to classify these leaves by the morphological system irrespective of the natural system of angiosperms. A new system of extinct platanoids and hamamelids, which is based on reproductive structures and includes two orders, Hamamelidales and Sarbaicarpales ordo. nov., is proposed. Hamamelidales comprises two extant families, Platanaceae (with the subfamilies Platanoideae subfam. nov. and Gynoplatananthoideae subfam. nov.) and Hamamelidaceae, and the extinct family Bogutchanthaceae fam. nov.; the new extinct order Sarbaicarpales ordo. nov. consists of two new families, Sarbaicarpaceae fam. nov. and Kasicarpaceae fam. nov. In a system of flowering plants that is based on molecular data, the families Platanaceae and Hamamelidaceae are assigned to remote orders, excluding close relationship (APG, 2003). At the same time, the system of APG II often contradicts morphological and paleontological data, while traditional ideas of morphologists concerning the common origin of these families have recently been supported by paleobotanic evidence. Probable origin of the families Platanaceae and Hamamelidaceae from a common polymorphic ancestral group is discussed.     

植物microRNA的保守性及其分布的分析

MicroRNA(miRNA)是真核生物中具有重要调控作用的小分子非编码RNA。本文对miRNA官网miRBase数据库Release 22.1中隶属于植物界的绿藻门、苔藓植物门、蕨类植物门、裸子植物门、被子植物门共计82个物种的miRNA进行了统计分析。miRBase共收录植物miRNA 前体8 615个,成熟miRNA 10 414条,隶属于2 892个miRNA家族。绿藻门miRNA与其他4个门miRNA无同源性;对其他4个门植物miRNA的保守性进行研究,发现存在于2个植物门的miRNA家族有26个,属于中度保守miRNA家族;14个miRNA家族存在于3个及3个以上植物门中,属于高度保守miRNA家族,其中7个miRNA家族系苔藓、蕨类、裸子和被子植物共有,是植物中最保守的miRNA。分析表明,超过30个miRNA家族的植物有35种。进一步对40个中度或者高度保守miRNA在35种植物中的分布进行研究,发现miRNA家族及其成员在物种间的分布存在较大的差异。这些分布上的差异一方面反映不同植物中miRNA的研究深度不同,另一方面也反映出miRNA在植物进化过程中的适应性调整。研究不同植物中miRNA家族的分布,可在miRNA水平为植物早期进化同源性的研究提供分子依据。