基于ITS序列探讨杜鹃属的亚属和组间系统关系

首次报道了 15种杜鹃属 (Rhododendron)植物、1种杜香属 (Ledum)植物和Cassiopefastigiata的内转录间隔区(ITS) (包括 5 .8S)序列。加上从GenBank下载的 13种杜鹃属植物和Bajiariaracemosa的ITS序列 ,以C .fastigiata和B .racemosa为外类群 ,用最大简约法对杜鹃属的亚属和组间的系统关系进行了分析。结果表明 :1)杜鹃属是一个单系类群 ,叶状苞亚属为杜鹃属的基部类群 ;2 )杜香属确应归并到杜鹃属中 ,且与有鳞杜鹃亚属有较近的亲缘关系 ;3)有鳞杜鹃亚属和杜香构成一个单系分支 ,该分支是其余无鳞杜鹃花的姐妹群 ;4 )由无鳞杜鹃花组成的一个分支的内部支持率较低 ,其中常绿杜鹃亚属和映山红亚属均为内部支持率很高的单系类群 ,而羊踯躅亚属和马银花亚属均为多系类群 ;5 )在马银花亚属中 ,长蕊杜鹃组和马银花组均分别得到强烈支持 ,马银花组与异蕊杜鹃亚属可能构成姐妹群关系 ,异蕊杜鹃亚属和马银花组组成的一个分支可能与映山红亚属构成姐妹群关系。     

基于ITS序列探讨杜鹃属的亚属和组间系统关系

首次报道了15种杜鹃属(Rhododendron)植物、1种杜香属(Ledum)植物和Cassiope fastigiata的内转录间隔区(ITS) (包括5.8S)序列.加上从GenBank下载的13种杜鹃属植物和Bajiaria racemosa的ITS序列,以C. fastigiata和B. racemosa为外类群,用最大简约法对杜鹃属的亚属和组间的系统关系进行了分析.结果表明: 1)杜鹃属是一个单系类群,叶状苞亚属为杜鹃属的基部类群; 2)杜香属确应归并到杜鹃属中,且与有鳞杜鹃亚属有较近的亲缘关系; 3)有鳞杜鹃亚属和杜香构成一个单系分支,该分支是其余无鳞杜鹃花的姐妹群; 4)由无鳞杜鹃花组成的一个分支的内部支持率较低,其中常绿杜鹃亚属和映山红亚属均为内部支持率很高的单系类群,而羊踯躅亚属和马银花亚属均为多系类群; 5)在马银花亚属中,长蕊杜鹃组和马银花组均分别得到强烈支持,马银花组与异蕊杜鹃亚属可能构成姐妹群关系,异蕊杜鹃亚属和马银花组组成的一个分支可能与映山红亚属构成姐妹群关系.     

中国锦鸡儿属的分子系统发育

测定了中国锦鸡儿属Caragana各属下分类群20个代表种的ITS、trnL-F和trnS-G序列.基于3种DNA片段的单独分析所获得的系统发育树具有相似的拓扑结构;3种片段的合并分析提高了各分支的支持度,并获得了相似的系统发育树.落轴亚属subgen.Caragana的种类构成了一个在系统树上首先分化出来的单系分支,与形态特征和地理分布的研究一致.短齿系ser. Occidentales和长齿系ser. Bracteolatae的代表种构成了1个单独的分支,因此短齿系应被放入长齿系所属刺叶组sect.Longspina 而不是针刺组sect.Spinosae或sect.Pruinosa.分子系统学证据支持依据叶片宽窄在掌叶组sect.Frutescentes中再划分2个系的形态学研究结论;但Ser.Dasyphyllae和针刺系ser.Spinosae的亲缘关系较近,系统发育分析的结果似乎不支持在针刺组中单独划分2个系.宿轴类的物种聚成一个单系的分支,因此应被处理为一个组--鬼箭组sect.Jubatae;荚果里面被毛和无毛的种类各自构成2个小支,支持依据该特征在组下分系.系统树显示Sanczir定义的sect.Tragacanthoides然为多系类群,应将该组中所包含的刺叶组、针刺组、和鬼箭组的种类划分出来.基于ITS的遗传距离表明卷叶锦鸡儿C. ordosica与藏锦鸡儿C, tibetica应该是2个不同的种.     

基于ITS序列对中国簇毛黄耆亚属(黄耆属)系统学问题的初步研究

测定了簇毛黄耆亚属(Pogonophace)4组8种和外类群Caragana roborovskyi的ITS序列,从GenBank中调出相关12属47种的ITS序列,组成数据距阵,应用PAUP程序中的最大简约法构建了系统发育树状图.扁荚组(Sect. Sesbanella)与亚属其余类群在系统树上处于不同的分支,亲缘关系较远,这个亚属不是一个单系类群;膨果组(Sect. Bibracteola),背扁组(Sect. Phyllolobium)和袋果组(Sect. Trichostylus)作为一个单系类群能得到ITS序列的支持,但与鱼鳔槐亚族比与黄耆属其他类群的关系更近; Astragatus complanatus和A. tribulifolius可能为一对替代种;亚属下的分组以及膨果组下系的划分都得不到ITS序列分析的支持.     

基于ITS序列对中国簇毛黄耆亚属（黄耆属）系统学问题的初步研究

测定了簇毛黄耆亚属（Pogonophace)4组8种和外类群Caragana roborovskyi的ITS序列,从GenBank中调出相关12属47种的ITS序列,组成数据距阵,应用PAUP程序中的最大简约法构建了系统发育树状图。扁荚组（Sect.Sesbanella)与亚属其余类群在系统树上处于不同的分支,亲缘关系较远这个亚属不是一个单系类群;膨果组（Sect.Bibracteola)。背扁组（Sect.Phyllolobium)和袋果组（Sect.Trichostylus)作为一个单系类群能得到ITS序列的支持,但与分组以及膨果组下系的划分都得不到ITS序列分析的支持。     

蒿属与邻近属的谱系分支分析

本文首次报道“蒿属与邻近属的谱系分支分析”,结果如下:在蒿自然群中,蒿属和绢蒿属及线叶菊属和栉叶蒿属各为一对姐妹群,后一对姐妹群还与毛蒿自然群有较近的亲缘关系;紊蒿属和百花蒿属在进化过程中,作为两个独立的属,很早就与蒿自然群其它属分化出。在蒿属各组中,腺毛蒿组和白苞蒿组为一对姐妹群,并与艾组构成姐妹关系;龙蒿亚属三个组(龙蒿组、牡蒿组和球蒿组)的亲缘关系很接近,且与友蒿组有较近的亲缘关系。 研究的结果支持林有润的蒿属与蒿自然群的演化假说和紊蒿作为一个独立的属的观点以及将中国蒿属分为蒿亚属和龙蒿亚属以及七个组的观点。根据谱系分支分析的结果以及形态上的特征,建议在蒿属下建立一新亚属,灰蒿亚属。     

部分百里香属植物分子系统学研究

采用ITS序列分析和ISSR分子标记技术,对中国野生百里香(5个种2个变种)及国外百里香(2个种)共计20份材料进行了属内种间及种下水平的系统发育和亲缘关系研究.结果表明:(1)ITS序列的系统发育树能较好地说明百里香属种间亲缘关系,地椒、地椒亚洲变种、百里香和Thymus serpyllum共同聚为一组,Bootstrap支持率为96%,表现为较近的亲缘关系;(2)基于ITS序列的系统发育树和ISSR多态性标记的聚类分析均将地椒怀远居群和地椒展毛变种兴凯居群聚为单独的一组,表现出与其它供试材料间较为明显的遗传差异;(3)ISSR遗传多态性分析将地椒、地椒亚洲变种和百里香很好的聚类;种下居群间的聚类则体现了与地理分布之间一定的相关性.将本实验结果与野外考查及形态学比较相结合,可以得出以下结论:地椒、地椒亚洲变种和百里香三者之间属于近缘种,并与国外的T.serpyllum种间有很近的亲缘关系;支持《黑龙江植物志》将地椒展毛变种兴凯居群列为单独的一个种;地椒怀远居群在遗传背景及分布生境上有很大的特殊性,对其在百里香属植物中的系统地位仍需进一步研究确定.     

睡莲科的系统发育:核糖体DNA ITS区序列证据

以金鱼藻Ceratophyllum demersum为外类群,使用PAUP4.0b4A软件对睡莲科Nymphaeaceae植物7属11个代表种的ITS区序列进行了系统发育分析。采用最大简约法分析获得了3个最简约树,步长为1125,一致性指数(CI)和维持性指数(RI)值分别为0.7618和0.7214。利用3个最简约树获取严格一致树。结果表明:(1)莲属Nelumbo位于系统树的基部,自展支持率为100%,可从睡莲科中独立出来成立莲科Nelumbonaceae和莲目Nelumbonales;(2)萍蓬草属Nuphar是一单系类群,位于分支Ⅱ的基部,并和睡莲科其他属(不包括莲属)植物聚在一起构成姐妹群,故萍蓬草属仍应置于睡莲科中;(3)水盾草属Cabomba和莼菜属Brasenia聚成一小支并构成姐妹群,自展支持率为99%,说明这两属之间亲缘关系较近;(4)睡莲属和芡实属Euryale、王莲属Victoria聚成一小支并构成姐妹群,自展支持率为94%,说明三者亲缘关系较近,仍应置于睡莲科中。     

基于线粒体COⅠ基因的凤蝶亚科部分物种系统发育关系

通过对凤蝶亚科Papilioninae11属27种的线粒体细胞色素c氧化酶Ⅰ基因(COⅠ)序列测定,以阿波罗绢蝶Parnassius apollo为外群,分别采用邻接法(NJ)、最大简约法(MP)和最大似然法(ML)构建凤蝶亚科的系统发育树,初步探讨了其系统发育关系。结果显示,凤蝶亚科11属27个物种分为4个主要的分支,分别是裳凤蝶族Troidini、凤蝶族Papilionini、燕凤蝶族Lampropterini和喙凤蝶族Teinopalpini,与传统分类学观点一致。其中,燕凤蝶族构成凤蝶亚科系统发育树基部的一个独立分支,且为单系发生。凤蝶属Papilio中美凤蝶亚属Menelaides和翠凤蝶亚属Princeps首先相聚,华凤蝶亚属Sinoprinceps和凤蝶亚属Papilio亲缘关系较近,随后两分支再聚为一支,构成凤蝶属。本研究结果从分子水平验证了凤蝶亚科传统的形态分类地位,并为澄清凤蝶亚科物种间系统发育关系提供了基础资料。     

珍珠菜属系统发育关系的初步研究

本文运用形态学性状对珍珠菜属（Lysimachia)进行系统发育分析。内类群包括珍珠菜属29个代表种以及珍珠菜族其它单种、寡种属;仙客来属（Cylclamen)被选作外类群。最简约性分析表明,珍珠菜属并不构成－自然分类群;在其严格一致化树的二岐分支中,异花珍珠菜（L.crispidens)单独构成一支,其它所有内类群构成一支。香草亚属（subgen.Idiophyton)、木黄连花亚属（subgne.Lysimachiopsis)以及珍珠菜亚属（subgen.palladia)均表现为单系群,而黄连花亚属（subgen.Lysimachia)则为一异形的并系群。球尾花亚属（subgen.Naumburgia)仍“内藏”于珍珠菜属的主体之中。而喉鳞花亚属（subgen.Seleucia)则偏离出来而与七瓣莲属（Trien talis)构成姐妹群。如何准确地界定珍珠菜属和进行属下分类群的划分,还需进一步研究。     

Phylogeny, biogeography, and ecology of Ficus section Malvanthera (Moraceae)

We conducted the first molecular phylogenetic study of Ficus section Malvanthera (Moraceae; subgenus Urostigma) based on 32 Malvanthera accessions and seven outgroups representing other sections of Ficus subgenus Urostigma. We used DNA sequences from the nuclear ribosomal internal and external transcribed spacers (ITS and ETS), and the glyceraldehyde-3-phosphate dehydrogenase (G3pdh) region. Phylogenetic analysis using maximum parsimony, maximum likelihood and Bayesian methods recovered a monophyletic section Malvanthera to the exclusion of the rubber fig, Ficus elastica. The results of the phylogenetic analyses do not conform to any previously proposed taxonomic subdivision of the section and characters used for previous classification are homoplasious. Geographic distribution, however, is highly conserved and Melanesian Malvanthera are monophyletic. A new subdivision of section Malvanthera reflecting phylogenetic relationships is presented. Section Malvanthera likely diversified during a period of isolation in Australia and subsequently colonized New Guinea. Two Australian series are consistent with a pattern of dispersal out of rainforest habitat into drier habitats accompanied by a reduction in plant height during the transition from hemi-epiphytic trees to lithophytic trees and shrubs. In contradiction with a previous study of Pleistodontes phylogeny suggesting multiple changes in pollination behaviour, reconstruction of changes in pollination behaviour on Malvanthera, suggests only one or a few gains of active pollination within the section.     

Phylogenetic relationships of functionally dioecious FICUS (Moraceae) based on ribosomal DNA sequences and morphology

Figs (Ficus, Moraceae) are either monoecious or gynodioecious depending on the arrangement of unisexual florets within the specialized inflorescence or syconium. The gynodioecious species are functionally dioecious due to the impact of pollinating fig wasps (Hymenoptera: Agaonidae) on the maturation of fig seeds. The evolutionary relationships of functionally dioecious figs (Ficus subg. Ficus) were examined through phylogenetic analyses based on the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and morphology. Forty-six species representing each monoecious subgenus and each section of functionally dioecious subg. Ficus were included in parsimony analyses based on 180 molecular characters and 61 morphological characters that were potentially informative. Separate and combined analyses of molecular and morphological data sets suggested that functionally dioecious figs are not monophyletic and that monoecious subg. Sycomorus is derived within a dioecious clade. The combined analysis indicated one or two origins of functional dioecy in the genus and at least two reversals to monoecy within a functionally dioecious lineage. The exclusion of breeding system and related characters from the analysis also indicated two shifts from monoecy to functional dioecy and two reversals. The associations of pollinating fig wasps were congruent with host fig phylogeny and further supported a revised classification of Ficus.     

Biogeographical and phylogenetic origins of African fig species (Ficus section Galoglychia)

Ficus section Galoglychia (subgenus Urostigma; Moraceae) includes 72 species restricted to the African floristic region (a few extending to the Arabian Peninsula and Socotra). We present the first molecular phylogenetic analysis of the section including 56 ingroup (representing 44 species) and three outgroup taxa, to investigate its monophyly, classification and evolution. We used sequence data from the nuclear ribosomal internal and external transcribed spacers (ITS and ETS). Our results suggest that section Galoglychia is paraphyletic to the neotropical section Americana, although this is not supported by bootstrap analysis and only weakly supported by Bayesian posterior probabilities. Maximum parsimony analysis conflict with maximum likelihood and Bayesian analyses with respect to the closest relatives of section Americana in Africa. The subsections of section Galoglychia proposed by Berg [Berg, C.C., 1986. Subdivision of Ficus subg. Urostigma sect. Galoglychia (Moraceae). Proc. Kon. Ned. Akad. Wetensch., Ser. C, 89, 121-127] are generally supported. We find two major clades of section Galoglychia within Africa possibly corresponding to two main centres of diversity. One clade comprises members of subsections Platyphyllae and Chlamydodorae, which are more concentrated in Eastern Africa, and extend to Madagascar and neighbouring archipelagos (Comores, Mascarenes, Aldabra Islands and Seychelles). The other main clade includes members of subsections Caulocarpae, Cyathistipulae, Crassicostae and Galoglychia, which are concentrated in West and Central Africa.     

Molecular phylogenetics of Acacia (Fabaceae: Mimosoideae) based on the chloroplast MATK coding sequence and flanking TRNK intron spacer regions

The tribe Acacieae (Fabaceae: Mimosoideae) contains two genera, the monotypic African Faidherbia and the pantropical Acacia, which comprise about 1200 species with over 950 confined to Australia. As currently recognized, the genus Acacia is subdivided into three subgenera: subg. Acacia, subg. Aculeiferum, and the predominantly Australian subg. Phyllodineae. Morphological studies have suggested the tribe Acacieae and genus Acacia are artificial and have a close affinity to the tribe Ingeae. Based on available data there is no consensus on whether Acacia should be subdivided. Sequence analysis of the chloroplast trnK intron, including the matK coding region and flanking noncoding regions, indicate that neither the tribe Acacieae nor the genus Acacia are monophyletic. Two subgenera are monophyletic; section Filicinae of subgenus Aculeiferum does not group with taxa of the subgenus. Section Filicinae, eight Ingeae genera, and Faidherbia form a weakly supported paraphyletic grade with respect to subg. Phyllodineae. Acacia subg. Aculeiferum (s. s.) is sister to the grade. These data suggest that characters currently used to differentiate taxa at the tribal, generic, and subgeneric levels are polymorphic and homoplasious in cladistic analyses.     

基于ITS序列探讨杜鹃花属马银花组的系统发育

以杜鹃花属叶状苞亚属Rhododendron　subg. Therorhodion (Maxim.) Gray 的叶状苞杜鹃R. redowskianum Maxim.为外类群,使用PAUP4.0b8软件对马银花亚属sub g. Azaleastrum Planch.的马银花组sect. Azaleastrum (Planch.) Maxim. 7种1 变种和长蕊杜鹃组sect. Choniastrum Planch. 2种及2个相关的单型亚属（异蕊杜鹃 亚属subg. Mumeazalea Max     

A molecular phylogeny of the grass subfamily Panicoideae (Poaceae) shows multiple origins of C4 photosynthesis

DNA sequence data from the chloroplast gene ndhF were analyzed to estimate the phylogeny of the subfamily Panicoideae, with emphasis on the tribe Paniceae. Our data suggest that the subfamily is divided into three strongly supported clades, corresponding to groups with largely identical base chromosome numbers. Relationships among the three clades are unclear. In unweighted parsimony analyses, the two major clades with x = 10 (Andropogoneae and x = 10 Paniceae) are weakly supported as sister taxa. The third large clade corresponds to x = 9 Paniceae. In analyses under implied weight, the two clades of Paniceae are sisters, making the tribe monophyletic. Neither resolution is strongly supported.Our molecular phylogenies are not congruent with previous classifications of tribes or subtribes. Based on this sample of species, we infer that C(4) photosynthesis has evolved independently several times, although a single origin with multiple reversals and several reacquisitions is only slightly less parsimonious. The phosphoenol pyruvate carboxykinase (PCK) subtype of C(4) photosynthesis has evolved only once, as has the NAD-malic enzyme (ME) subtype; all other origins are NADP-ME. Inflorescence bristles are apparently homologous in the genera Setaria and Pennisetum, contrary to opinions of most previous authors. Some genera, such as Digitaria, Echinochloa, and Homolepis are supported as monophyletic. The large genus Paspalum is shown to be paraphyletic, with Thrasya derived from within it. As expected, Panicum is polyphyletic, with lineages derived from multiple ancestors across the tree. Panicum subg. Panicum is monophyletic. Panicum subg. Dichanthelium, subg. Agrostoides, and subg. Phanopyrum are unrelated to each other, and none is monophyletic. Only Panicum subg. Dichanthelium sect. Dichanthelium, represented by P. sabulorum and P. koolauense, is monophyletic. Panicum subg. Megathyrsus, a monotypic subgenus including only the species P. maximum, is better placed in Urochloa, as suggested by other authors.     

Phylogeny of Iris based on chloroplast matK gene and trnK intron sequence data

Phylogenetic analyses of 46 species of Iris, representing all subgenera and all sections except Regelia, Brevituba, and Monolepis, utilized matK gene and trnK intron sequence data. Sequence data show that Iris is paraphyletic because Belamcanda chinensis is resolved within the genus. The two largest subgenera, Iris and Limniris, are both resolved as polyphyletic. With the removal of section Hexapogon, subgenus Iris is weakly supported as monophyletic. Relationships within subgenus Limniris are more complex with the subgenus as currently circumscribed representing eight independent origins among the species included in this study. Several potential monophyletic groups are identified including subgenus Scorpiris, series Spuria (subgenus Limniris section Limniris), and a clade of section Limniris species from North America and Asia.     

壳斗科栎属青冈亚属的花粉形态及其系统学意义

对栎属青冈亚属17个种及炭栎花粉形态进行扫描电镜观察。结果表明:青冈亚属和炭栎花粉均为三拟孔沟,球形至长球形,(15～28.0)μm×(15.0～25.6)μm。花粉外壁纹饰可划分为3种:(1)蠕虫状(包括皱波状)、(2)聚合颗粒状、(3)棒状或小刺状。各纹饰在组间镶嵌分布。棒状及小刺状纹饰为栎属花粉较为原始式样,并为青冈亚属与高山栎组及部分巴东组(sect.Cerris)共有,推测其间具有较其它栎类更为接近的亲缘关系,可能为广义栎属中较为基础的类群,而与栎亚属sect.Quercuss.s.,Lobatae和Protobalanus关系较远。花粉形态对广义栎属系统分类价值仅适用于较高分类阶元。