Veronica: Chemical characters for the support of phylogenetic relationships based on nuclear ribosomal and plastid DNA sequence data

Molecular phylogenetic analyses have revealed many relationships in Veronica (Plantaginaceae) never anticipated before. However, phytochemical characters show good congruence with DNA-based analyses. We have analysed a combined data set of 49 species and subspecies derived from the nuclear ribosomal ITS-region (18 new sequences) and the plastid trnL-F region (12 new sequences) of Veronica emphasizing subgenera Chamaedrys and Pocilla and separate analyses of subgenera Pentasepalae (ITS only) and Pseudolysimachium. Results for subgenus Chamaedrys show that European and Asian perennial species are monophyletic sister groups with the annual species consecutive sisters to them. All species of Veronica that contain cornoside are found in this subgenus, although some species seem to have secondarily lost the ability to produce this compound. Subgenera Pocilla and Pentasepalae are well supported sister groups characterized by the occurrence of 8-hydroxyflavones. The traditional subsection Biloba of subgenus Pocilla is biphyletic with Veronica intercedens being clearly separate from the rest of the group. This result is mirrored by the unusual phytochemical arsenal of V. intercedens, which is the only species in the genus analysed to date to contain melittoside and globularifolin. Subgenus Pentasepalae appears to be a clade of diverse lineages from southwestern Asia and a single European clade. Species shown to have 6-hydroxyflavones do not form a monophyletic group. Subgenus Pseudolysimachium seems to have originated in Eastern Asia. 6-Hydroxyflavones acylated with phenolic acids are common in this subgenus but may have originated only later in the evolution of the group. Possible chemotaxonomic markers for other groups are discussed.     

Phylogeny of Rhododendron section Vireya (Ericaceae) based on two non-coding regions of cpDNA

Section Vireya (Blume) Copel.f. is one of the most morphologically diverse groups of the genus Rhododendron. Vireyas have a unique distribution for the genus, being predominantly found throughout the Malesian Archipelago. The alpha taxonomy of section Vireya is relatively well understood and taxa are easily distinguished from other rhododendrons by their general appearance. Defining characteristics of the section the possession of seeds with tailed appendages at both ends, the twisting of capsule valves after opening, placentas that separate as thread-like structures from the central axis as the capsule opens are all subject to exceptions. Phylogenetic analyses of two cpDNA regions, psbA-trnH and trnT-trnL intergenic spacers are reported. The results of each analysis were generally congruent, with clades relating strongly to geographic areas. Section Vireya is monophyletic with the inclusion of at least one species of section Rhododendron. Only two of the seven subsections currently circumscribed are monophyletic: Malayovireya Sleumer and Siphonovireya Sleumer. ``Euvireya', all subsections excluding the paraphyletic subsection Pseudovireya, is monophyletic and includes two major clades, one restricted to eastern Malesia and the other to the western and middle Malesia.     

A model for determining ex situ conservation priorities in big genera is provided by analysis of the subgenera of <Emphasis Type="Italic">Rhododendron</Emphasis> (Ericaceae)

The large size and complex taxonomy of big genera complicates decision making for conservation. We propose that Rhododendron, comprising some 1215 taxa, divided into nine subgenera and many sections, can be used as a model for other big genera. Although Red List assessments placed 715 taxa in a threat category, or listed them as Data Deficient, and moreover Target 8 of the Global Strategy for Plant Conservation requires 75 % of Red List taxa to be held in ex situ collections by 2020, to date there have been few studies of Rhododendron ex situ collections or conservation priorities. Utilising the subgenus structure of Rhododendron as a framework for examining conservation priorities, we analysed the Red List and determined that subgenera Vireya and Hymenanthes have the most acute conservation issues. Examination of taxa in cultivation shows that 844 of 1215 taxa (70 %) are in cultivation, with subgenera varying from 45 to 100 %. Of the 715 Red List taxa, 400 (56 %) are in cultivation, with subgenera varying from 28 to 72 %. Subgenera Vireya and Azaleastrum have the poorest representation in cultivation and should have precedence for ex situ conservation. As no subgenus reaches the requirement for Target 8, further planning is needed for ex situ conservation of Rhododendron. After combining the two analyses, we propose the priorities for ex situ conservation should be ordered (i) Vireya, (ii) Azaleastrum and (iii) Hymenanthes. Finally, we propose five conservation actions for Rhododendron, and summarise our approach as a model for conservation of other big genera.     

Phylogenetic analysis based on structural and combined analyses of Rhus s.s. (Anacardiaceae)

Structural data were combined with trnL‐F and internal transcribed spacer sequences from other studies and with new sequences representing ten additional species to clarify the phylogenetic relationships of Rhus s.s. These data indicate that Rhus s.s and both subgenera, Rhus and Lobadium, are monophyletic. The genus Rhus is supported as monophyletic by the presence of red glandular hairs on the berries and inflorescence axis, cilia on the sepals and glands on the leaf blades. Subgenus Rhus can be identified by the presence of more than seven resin channels in the petiole, weakly percurrent tertiary veins and a type I vascular system in the mid‐vein. Subgenus Lobadium is characterized by the presence of short bracteoles and pedicels. This subgenus is divided into four sections, Lobadium, Rhoeidium, Styphonia and Terebinthifolia. Section Lobadium has trifoliate leaves; section Rhoeidium is monotypic, including only Rhus microphylla; section Styphonia is supported by five synapomorphies, including an incomplete marginal vein, fibres in the petiole, a thick cuticle, two layers of palisade parenchyma and prismatic crystals in the mesophyll; and section Terebinthifolia has gelatinous xylary fibres in the petiole. Hypotheses about the evolutionary changes of these characters are presented based on the cladograms. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 452–468.     

Mitochondrial DNA phylogenetic analysis of the genus Laparocerus (Coleoptera, Curculionidae, Entiminae). I. The Madeiran clade

Laparocerus are plant‐chewing flightless weevils distributed on oceanic islands in Macaronesia, with a single species in Morocco. The genus has a complicated taxonomic history with several subgenera described. To assist in a taxonomical revision of the group, a molecular study was undertaken. In this first contribution, the species from the Azores and Madeira archipelagos are studied together with representatives of subgenera from the Canary Islands and the single known continental species (46 OTUs). Phylogenetic analyses are based on sequence data from mitochondrial cytochrome oxidase II (COII) and the ribosomal 16S ribosomal RNA (16S rRNA) genes (combined data set 1023 bp), with additional data from the nuclear elongation factor 1α (EF‐1α) for some selected species. Maximum likelihood (ML) and Bayesian analyses show that all Madeiran species are monophyletic and form a monophyletic group with the Afro‐Canarian samples. Species of the genus Lichenophagus appear within the Madeiran and Canarian Laparocerus clades, but separated in accordance with their respective island origin. Thus, Lichenophagus is here restricted to Madeiran species and proposed as subgenus (status novo) of Laparocerus. Conversely, the Laparocerus subgenus Drouetius from the Azores is revealed to be a separate and distant outgroup, in agreement with its morphological distinctiveness, deserving an independent genus status. Internal relationships within the Madeiran clade are discussed and compared with morphologically defined species groups. The Madeiran monotypic subgenus Cyphoscelis is not supported by the genetic data and synonymized (nov. syn.) with Laparocerus. Subgenera Laparocerus and Atlantis prove to be polyphyletic. Consequently a restriction to monophyletic and morphologically congruent clades is proposed. A cryptic species vicariant of Laparocerus morio was detected and recognized as L. chaoensis, status novo. Other cases of discrepancy between the genetic results and the traditional taxonomy are discussed in detail in the light of mitochondrial introgression, incomplete lineage sorting or poor taxonomy hypotheses.     

Intron-flanking EST–PCR markers: from genetic marker development to gene structure analysis in Rhododendron

With a long-term goal of constructing a linkage map of Rhododendron enriched with gene-specific markers, we utilized Rhododendron catawbiense ESTs for the development of high-efficiency (in terms of generating polymorphism frequency) PCR-based markers. Using the gene-sequence alignment between Rhododendron ESTs and the genomic sequences of Arabidopsis homologs, we developed ‘intron-flanking‘ EST–PCR-based primers that would anneal in conserved exon regions and amplify across the more highly diverged introns. These primers resulted in increased efficiency (61% vs. 13%; 4.7-fold) of polymorphism-detection compared with conventional EST–PCR methods, supporting the assumption that intron regions are more diverged than exons. Significantly, this study demonstrates that Arabidopsis genome database can be useful in developing gene-specific PCR-based markers for other non-model plant species for which the EST data are available but genomic sequences are not. The comparative analysis of intron sizes between Rhododendron and Arabidopsis (made possible in this study by aligning of Rhododendron ESTs with Arabidopsis genomic sequences and the sequencing of Rhododendron genomic PCR products) provides the first insight into the gene structure of Rhododendron. Electronic Supplementary Material Supplementary material is available for this article at     

未来气候变化对粤港澳地区杜鹃花适生区的影响

位于我国南方丘陵的粤港澳地区拥有丰富杜鹃花资源,长期以来受杜鹃花不适宜在高温低海拔地区进行开发利用等思想的影响,该区域野生杜鹃花的开发、保护与利用研究寥寥无几,但低海拔野生杜鹃花在气候变化下正面临较高灭绝风险。基于粤港澳地区杜鹃花属(Rhododendron)14个筛选后的野生物种229个标本点位数据,利用最大熵模型(Maxent)模拟粤港澳地区野生杜鹃花在2070年低、中、高3种温室气体排放模式(RCP2.6、RCP4.5、RCP8.5)下的适生区范围大小与方向的变化及其主导环境变量。研究发现未来粤港澳地区野生杜鹃花的适生区范围整体呈缩小趋势,且随着温室气体排放浓度的增加,即从RCP2.6到RCP8.5,越来越多杜鹃花物种适生区呈现向高纬度、高海拔方向迁移的趋势;对杜鹃花分布影响最大的变量为最冷月的最低温、温度季节性和最干月降水量。本研究通过探究气候变化对野生杜鹃花适生区范围的影响,以期为粤港澳地区野生杜鹃花的保护与开发利用提供科学指导。     

Characteristics of ovary, ovule and mature megagametophyte in Rhododendron L. (Ericaceae) and their taxonomic significance

PALSER, B. F., PHILIPSON, W. R. & PHILIPSON, M. N., 1991. Characteristics of ovary, ovule and mature megagametophyte in Rhododendron L. (Ericaceae) and their taxonomic significance. The ovary, ovule and megagametophyte at the time the latter is mature are described for 177 species representing all subgenera, sections and most subsections recognized in Rhododendron. All three, but particularly the ovary, vary considerably. The ovary is compared among species as to size; shape of apex–tapered vs. depressed; relative dimensions; indumentum–five basic hair types; wall structure including crystal distribution and frequency, stomata, cuticular ornamentation; locule number, shape and size relative to radius; wall thickness relative to radius; placenta size, shape, depth of cleft, level of cleft junction, presence or not of a decurrent placental stalk ridge; number of ovules, their arrangement and orientation on placenta; and presence and distribution of internal stomata and hairs. The nectary which girdles the base of the ovary also varies in size, shape, indumentum, stomata and some internal features. The ovule is anatropous, unitegmic and tenuinucellate with the lateral and micropylar nucellus disappearing completely and the megagametophyte elongating into the micropyle in all species. Also common to almost all are an endothelium, hypostase, differentiated epidermis–most often tanniniferous, and starch in integument around egg apparatus and micropyle. There are differences in size, shape, proportion occupied by gametophyte and micropyle, thickness of integument, degree of differentiation of some features, amount and area of starch and occurrence of chalazal and micropylar tails or of incipient micropylar and/or chalazal appendages. The megagametophyte, which develops according to the Polygonum pattern, has two distinct portions, the chalazal bounded by the endothelium with small antipodal cells at its end and the usually broader micropylar part within the micropyle containing a rather large egg apparatus with distinctive synergids; starch is present in the central cell and the polar nuclei are most often fused. Differences occur in proportions of the parts to one another, amount of starch, etc. Sixty-three characters were entered onto a computer, clustered by two different techniques and dendrograms constructed. Personal analysis and both dendrograms show section Vireya to be characterized by a syndrome of distinctive features and clearly separated from the rest of the genus. Subgenus Hymenanthes also has its particular syndrome but is somewhat less distinct from the remainder of the genus. Even less distinct but still grouped together are species of section Choniasirum and of section Sciadorhodion. Many species of section Rhododendron and of subgenus Tsutsusi tend to cluster together but section Rhododendron and most sections of the azalea complex are more generalized and moderate in the ovary, ovule and megagametophyte characters and do not separate sharply from one another.     

GA3浸种处理对五种晚花杜鹃种子萌发的影响

晚花杜鹃(late flower Rhododendron)是一类花期较晚的杜鹃品种,具有较高的观赏价值,被广泛应用于庭院种植和园林绿化。随着旅游以及经济发展的需要,开发和利用晚花杜鹃资源显得非常迫切。自然条件下晚花杜鹃萌发率相对较低,因此为提高晚花杜鹃萌发率,探究不同浓度赤霉素(GA_3)处理对五种杜鹃种子萌发的影响,该文以五种晚花杜鹃(小白杜鹃、大白杜鹃、桃叶杜鹃、长蕊杜鹃和九龙山杜鹃)为实验材料,通过不同浓度(0、300、400、500、600、700 mg·L~(-1))的GA_3对五种晚花杜鹃种子进行24 h浸种处理,测定其发芽指数、发芽势、发芽率以及成苗率等指标,分别确定五种杜鹃种子萌发的最适GA_3浓度,并对相同处理下五种杜鹃种子的萌发率和成苗率进行比较。结果表明:(1) GA_3浸种对五种晚花杜鹃种子萌发具有促进作用,在适当GA_3浓度下五种杜鹃种子的发芽指数、发芽势和发芽率均显著高于对照组,萌发时滞、萌发高峰期和持续萌发时间均较对照组浓度相对缩短。(2)大白杜鹃、桃叶杜鹃和九龙山杜鹃种子在GA_3浓度为600 mg·L~(-1)处理时各项萌发指标相对较好;长蕊杜鹃以GA_3浓度为700 mg·L~(-1)浸种处理萌发效果相对较好;小白杜鹃以GA_3浓度为400和700 mg·L~(-1)处理最好。因此,在杜鹃的栽培中,可以采用赤霉素GA_3处理法提高种子发芽率,缩短萌发时间。     

杜鹃花属植物种间可交配性及其特点

该研究以杜鹃花属5亚属3组17亚组38种和共计91个可育组合及109个不育组合的杂交结果为依据,通过杂交可育指标频度分析,初步揭示该属植物种间可交配性的分布规律。结果表明:(1)根据育性等级频度的研究,可得到种间可交配性排序结果,即亚属级:常绿杜鹃亚属内杂交杜鹃亚属内杂交常绿杜鹃亚属×杜鹃亚属杜鹃亚属×映山红亚属常绿杜鹃亚属×映山红亚属常绿杜鹃亚属×羊踯躅亚属常绿杜鹃亚属×马银花亚属杜鹃亚属×羊踯躅亚属;亚组级:银叶杜鹃亚组×同亚属的其他亚组云锦杜鹃亚组内杂交云锦杜鹃亚组×银叶杜鹃亚组银叶杜鹃亚组×杜鹃亚属各组三花杜鹃亚组内杂交云锦杜鹃亚组×同亚属其他亚组云锦杜鹃亚组×杜鹃亚属各组常绿杜鹃亚属的其他亚组×杜鹃亚属各组。(2)种间可交配性与亲本间的亲缘关系及染色体倍性有明显的关联,与分类系统中所反映的类群亲缘关系契合,原始的杜鹃花属植物类群如常绿杜鹃亚属可能比较进化类群具有更广泛的可交配性。(3)坐果率、绿苗率、绿苗系数和单位可育种子数量及其等级频度能从不同的侧面反映杜鹃花属植物杂交可育性数量特征,但也分别存在某些局限性,建立综合评价方案和可育性等级频度指标十分重要。     

32种杜鹃花属植物亚属间杂交的可育性研究

为探索杜鹃花属植物亚属间杂交的可育性规律,该文对常绿杜鹃亚属(subgen. Hymenanthes)、杜鹃亚属(subgen. Rhododendron)及马银花亚属(subgen. Azaleastrum)、映山红亚属(subgen. Tsutsusi)和羊踯躅亚属(subgen. Pentanthera)的亚属间杂交进行了研究,共涉及杜鹃花属植物5亚属15亚组32种,杂交组合118个。结果表明:(1)杜鹃花属植物的亚属间杂交存在明显的生殖障碍,其可育性水平与亚属及其类群组合有关,高、中、低与不育比例为2∶16∶8∶92,可育比例仅20.0%,杜鹃亚属与马银花亚属等4个亚属级组合杂交未显现可育性。(2)亲本杂交组合方式对亚属间杂交有不同程度的影响,一些类群组合有明显的向性。以杜鹃亚属做母本与常绿杜鹃亚属的云锦杜鹃亚组杂交的可育组合比高于反交,且在有关大王杜鹃、粘毛杜鹃、露珠杜鹃和马缨花的杂交中也是如此,但与银叶杜鹃亚组杂交正好相反;另外,12对单向可育组合,分布于常绿杜鹃亚属与杜鹃亚属等4类亚属级杂交组合中。(3)杜鹃花属的亚属间杂交不亲和与败育现象明显,不可育组合百分率占80%,不能坐果是败育的主要表征,所有可育组合的绿苗率比值和单位种子数比值无一例达到相应母本的自然授粉水平。(4)双亲系统分类上的关系对亚属间可交配性具有重要影响并与可育程度一致,染色体倍性也有一定的作用。(5)有关研究为探索和认识杜鹃花属植物亚属间进化遗传联系提供了新的证据和思考,银叶杜鹃亚组可能是解释常绿杜鹃亚属与杜鹃亚属进化遗传联系的重要类群,杜鹃亚属的多鳞杜鹃可能与常绿杜鹃亚属具有广泛的血亲关系,其中多鳞杜鹃与岷江杜鹃彼此为生态相邻种并有可能在长期的演化过程中有遗传渗透,百合花杜鹃和毛肋杜鹃分别与映山红亚属、腺果杜鹃与马银花亚属,越峰杜鹃和繁花杜鹃分别与映山红亚属,大白杜鹃与羊踯躅亚属间的联系均需要深入研究。     

杜鹃花属植物干旱胁迫研究进展

杜鹃花为世界三大高山花卉和中国十大传统名花之一,具有极高的观赏价值和广阔的园林应用前景。但是,杜鹃花大多自然分布于高海拔山地,受遗传机制制约,性喜冷凉湿润气候,干旱是制约其迁地保育和园林应用的关键因子。杜鹃花种类繁多、分布地域较广、生态类型多样,不同物种(品种)对干旱胁迫的响应机制存在差异。该文从种子发芽、形态与解剖特征、生理与生化指标、基因表达等方面综述了杜鹃花对干旱胁迫的响应机制以及外源物质提高杜鹃花抗旱性的国内外研究进展,分析了当前该研究领域存在的不足,提出了今后工作中应加强不同生态类型及不同抗旱性杜鹃的水分利用策略和抗旱机制,以及菌根真菌提高杜鹃花抗旱性的基因调控机制与优良菌株筛选等研究,为我国杜鹃花多样性保育、抗旱性资源发掘及园林应用等提供参考依据。     

Identification and characterization of genome-wide long terminal repeat retrotransposons provide an insight into elucidating the trait evolution of five Rhododendron species

• Rhododendron is well-known for its beauty and colourful corolla. Although some high-quality whole-genome sequencing of it has been completed, there are few studies on long terminal repeat (LTR) retrotransposons in Rhododendron, which limits our ability to elucidate the causes of genetic variations in Rhododendron species.
• Properties of the intact Rhododendron LTR retrotransposons were investigated at a genome-wide level. Based on available data, the high-quality genomes from five species, i.e. R. griersonianum, R. simsii, R. henanense subsp. lingbaoense, R. mucronatum var. ripense and R. ovatum, were selected as targets with good assembly continuity.
• A total of 17,936 intact LTR retrotransposons were identified; these belong to superfamilies Copia and Gypsy, with 17 clades. The insertion time of these transposons was later than 120 million years ago (Mya), and the outbreak period was concentrated more recently than 30 Mya. Phylogenetic analysis revealed that many LTR retrotransposons might originate from intraspecific duplication. Current evidence also suggests that most LTR retrotransposons were inserted in the interstitial part of genes in R. griersonianum, R. simsii, R. henanense, and R. ovatum, and the functions of the inserted genes mainly involve starch metabolism, proteolysis, etc. The effect of the LTR retrotransposon on gene expression depends on its insertion site and activation. Highly expressed LTR retrotransposons tend to be younger.
• The results herein improve our knowledge of LTR retrotransposons in Rhododendron genomes and facilitate further study of genetic variation and trait evolution in Rhododendron.

     

Systematic overview of Krigia (Asteraceae-Lactuceae)

Cytological and morphological variation among Krigia species is examined. Krigia exhibits a broad range of chromosome numbers including n = 4, 5, 6, 9, 10, 15, and 30. Section Krigia is characterized by reflexed phyllaries and a base chromosome number of x = 5, while section Cymbia is characterized by erect phyllaries and chromosome numbers of n = 4, 6, and 9. The micromorphological characteristics of achenes, pappus, styles, corolla, pollen, stomata, and trichomes are documented using scanning electron microscopy. Among these, the pappus shows the greatest diversity and three major types are identified: 1) a pappus of many bristles and scales, as in K. dandelion, K. montana, and K. biflora; 2) a pappus of five bristles and five scales, as in K. virginica and K. occidentalis; and 3) an absent or highly reduced pappus, as in the K. cespitosa complex and K. wrightii. Thirty-five cytological and morphological characters are subjected to phylogenetic analyses. The two sections, Krigia and Cymbia, form monophyletic lineages. Within section Krigia, the annual species, K. virginica, forms an independent clade, while the perennial species, K. dandelion, K. biflora, and K. montana, form a monophyletic clade. Krigia montana and K. biflora are identified as sister species and a hybrid between these has been identified. The hybrid is more similar morphologically to K. montana than K. biflora. Within section Cymbia, phylogenetic relationships among K. wrightii, K. occidentalis, and K. cespitosa are uncertain. Nine taxa of Krigia are herein recognized: K. dandelion, K. biflora, K. biflora var. viridis (comb. nov.), K. montana, K. virginica, K. wrightii (comb. nov.), K. occidentalis, K. cespitosa, and K. cespitosa f. gracilis (comb. nov.). Phylogenetic relationships among 12 taxa of Krigia species are compared using various combinations of morphology, chloroplast DNA, and nuclear ribosomal DNA data. Tree topologies from different combinations of data are largely congruent. The most resolved phylogenetic tree is obtained using the combined data from morphology, chloroplast DNA, and nuclear ribosomal DNA.     

32种杜鹃花属植物在迁地保育条件下的自交研究

迁地保育条件下的杜鹃花属植物自交可育性一直缺乏系统的比较研究,该文对5亚属13亚组32种杜鹃花属植物的自交进行了数据采集与分析,初步揭示了迁地保育条件下杜鹃花属植物自交育性特征。结果表明:(1)自交可育与不育是杜鹃花属植物有性生殖中的两个并存现象,自交能育型种类或多于不育型。在受试的32种杜鹃花中,自交不育型10种、弱可育型5种、可育型7种、高可育型10种,其中27种的自交育性为首次报道,涵盖包括杜鹃亚属杜鹃组(sect.Rhododendron)和马银花亚属(subgen.Azaleastrum)及常绿杜鹃亚属(subgen.Hymenanthes)中银叶杜鹃亚组(subsect.Argyrophylla)等5个亚组在内的未被研究的类群。(2)通过与自然授粉有关育性指标的比较,发现不同种类的自交可育性指标有大幅度降低及增高这两类截然不同的现象,从而提出了自交可能是部分杜鹃花属植物的适应策略,或者对不利环境及其媒介条件的主动响应。(3)在云锦杜鹃亚组(subsect.Fortunea)这个被认为最原始的杜鹃花类群中,具备从自交不育到高可育的所有类型,并可能由此奠定整个杜鹃花属的遗传基础,而类群与种类分布的不同区域气候环境长期直接的或通过影响传粉媒介间接的作用,则可能是最终塑造该属植物自交育性多样化的外部动力。(4)该文还依据有关自交的研究结果,对杜鹃花属植物的迁地保育、育种、相关学科发展进行了讨论,并认为后合子期败育的理论不能完美地解释自交不能坐果的现象,而多倍体似不会导致自交不育。     

Molecular phylogeny of Old WorldTrifolium (Fabaceae), based on plastid and nuclear markers

Phylogenies of Old WorldTrifolium species were constructed using nucleotide sequence data of the internal transcribed spacers (ITS) of nuclear ribosomal DNA and chloroplast DNA restriction site data from PCR-amplified genes and genic regions (rbcL,trnK, andrpoC1–C2). Biogeography, morphological evolution, and the existing classification forTrifolium were examined. The genusTrifolium is strongly supported as monophyletic, however, only one small section (Chronosemium) is monophyletic, although the data are in conflict regarding its placement. The two largest sections of the genus, Sects.Lotoidea andTrifolium, are not supported as monophyletic, as currently circumscribed. Many members of Sect.Lotoidea are basal within the genus, supporting previously-proposed hypotheses concerning plesiomorphic morphological characters and a Mediterranean-Mideast biogeographic origin of the genus.     

头花杜鹃、陇蜀杜鹃及杜鹃属植物叶绿体基因组比较分析

头花杜鹃(Rhododendron capitatum)和陇蜀杜鹃(R. przewalskii)是极具观赏价值的野生花卉和药用植物。为探讨头花杜鹃和陇蜀杜鹃叶绿体基因组的遗传结构及进化特征,该研究利用 Illumina HiSeq 4000 平台对头花杜鹃和陇蜀杜鹃的叶绿体全基因组进行测序,经组装和注释后,结合 7 个已发表的杜鹃属植物叶绿体全基因组进行比较基因组学分析和系统发育分析。结果表明:(1)头花杜鹃和陇蜀杜鹃叶绿体全基因组呈典型的环状四分体结构,均由一个大单拷贝区(105 990、109 191 bp)、一个小单拷贝区(2 617、2 606 bp)和一对反向重复区(45 825、47 516 bp)构成,全长分别为200 257、206 829 bp。(2)头花杜鹃和陇蜀杜鹃叶绿体基因组中共鉴定出 263 个SSR位点,大部分 SSR 偏好使用 A/T 碱基,密码子偏好使用 A/U 结尾。(3)杜鹃属植物叶绿体全基因组中普遍存在基因丢失以及基因组重排等结构变异现象。该研究丰富了杜鹃属植物的基因组资源,为头花杜鹃、陇蜀杜鹃的资源开发、遗传进化、育种及系统发育相关研究提供了理论参考。     

FLAVONOID EVOLUTION IN DENDROSERIS (COMPOSITAE,LACTUCEAE) FROM THE JUAN FERNANDEZ ISLANDS,CHILE

Leaf flavonoid chemistry was examined from the three subgenera and 11 species of the endemic genus Dendroseris (Compositae, Lactuceae) of the Juan Fernandez Islands, Chile. Eight of the species are restricted to the older island (Masatierra, ca. 4 million years old), which is also closer to the mainland. Three species, one from each subgenus, are restricted to Masafuera, which is younger geologically (1–2 million years old) and 145 km further west of Masatierra. A total of 16 compounds was identified, with the 7-0-glucosides of the flavones apigenin and luteolin accounting for 12 of the constituents. Two glucosides of the flavonol quercetin were detected. Despite considerable interpopulation variation within species, six of the taxa have distinctive flavonoid profiles. Although there are few absolute differences among the subgenera, they can be distinguished chemically. Subgenus Rea contains the greatest number of compounds, and a previous cladistic analysis based on morphological features suggested this subgenus as most primitive. Subgenus Phoenicoseris is considered highly derived morphologically, and it has a reduced flavonoid chemistry. Very little reduction in flavonoid diversity was seen in the morphologically specialized subg. Dendroseris as compared to subg. Rea. A trend in reduction of numbers of compounds was seen for two of the three species on the younger island of Masafuera when compared to their presumed ancestors on Masatierra. Flavonoids of selected species of Hieracium and Hypochaeris, presumptive mainland progenitors of Dendroseris, reveal a close chemical affinity with the former genus.     

Phylogeny of mosquitoes of tribe Culicini (Diptera: Culicidae) based on morphological diversity

Harbach, R. E., Kitching, I. J., Culverwell, C. L., Dubois, J. & Linton, Y.‐M. (2012). Phylogeny of mosquitoes of tribe Culicini (Diptera: Culicidae) based on morphological diversity. —Zoologica Scripta, 41, 499–514. Relationships among taxa of the mosquito tribe Culicini are explored using 169 morphological characters from 86 exemplar species representing the four genera and 26 subgenera of Culicini, most species groups and subgroups of subgenus Culex and an outgroup of five species from five other tribes. We analysed the data set, with multistate characters treated as unordered, under implied weights with values of K ranging from 1 to 20, implemented by TNT. Each analysis, except K = 4, produced a single most parsimonious (fittest) cladogram (MPC). The topology of the ingroup was identical for K = 6–11, whereas the MPCs for K = 14–20 differed only in the position of a single species, which occupied the same position in the K = 16 and K = 6–11 topologies. The K = 9 and K = 16 trees were given further consideration. In both these cladograms, Lutzia is sister to a clade comprising genera Culex, Deinocerites and Galindomyia. The two topologies have 13 clades in common, but their arrangements differ primarily because of Culex (Culex) duttoni acting as a ‘rogue’ taxon. We evaluated the effect of removing this species from the K = 9 and K = 16 analyses and chose the refined K = 9 topology as the best hypothesis of relationships within Culicini. Genus Culex is not monophyletic because it includes Deinocerites and Galindomyia as derived members of the New World subgenera. With the exception of subgenera Culex, Eumelanomyia and Neoculex, there is strong support for the monophyly of all genera and subgenera. Subgenus Culex would be monophyletic were four other subgenera included and three other taxa (the Afrotropical Cx. duttoni, Neotropical Cx. apicinus and the Australasian Atriceps Group) excluded.