Phylogenetic relationships of North American Antirrhinum (Veronicaceae)

Species of the genus Antirrhinum (Veronicaceae) provide excellent opportunities for research on plant evolution given their extensive morphological and ecological diversity. These opportunities are enhanced by genetic and developmental data from the model organism Antirrhinum majus. The genus Antirrhinum includes 15 New World species in section Saerorhinum and 21 Old World species in sections Antirrhinum and Orontium. Phylogenetic analyses of sequences of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA were conducted for 19 Antirrhinum species, including all species from the New World, and 13 related genera in the tribe Antirrhineae. These analyses confirm the monophyly of Antirrhinum given the inclusion of the small genus Mohavea and exclusion of A. cyathiferum. The New World species, all of which are tetraploid, form a clade that is weakly supported as sister to the Old World sect. Orontium. The Old World species in sect. Antirrhinum form a well-supported clade that is sister to the remainder of the genus. In addition, both molecular and morphological data are used in the most comprehensive effort to date focused on recovering the phylogenetic relationships among the extremely diverse species in section Saerorhinum.     

Delphinium nortonii Dunn的重新描述

通过检查藏南翠雀花Delphinium nortonii 的主模式标本,发现《中国植物志》、《西藏植物志》和《Flora of China》中对该种的鉴定和描述有误。该种的花的退化雄蕊黑褐色,属于翠雀亚属的密花翠雀花组subgen. Delphinastrum sect. Elatopsis, 而上述几种植物志中长1以来将其置于退化雄蕊为蓝色或蓝紫色的翠雀组sect. Delphinastrum中。这几种植物志中记载的D. nortonii 实际上代表一个新种,即李恒翠雀花D. lihengianum。     

Frequency of spontaneous amphiploids in Gilia (Polemoniaceae) hybrids

This paper reports the frequency of spontaneous amphiploids or neopolyploids in experimental interspecific hybrids in two annual sections of Gilia (Polemoniaceae, sects. Arachnion and Gilia, x = 9). In each section the species were intercrossed in numerous hybrid combinations to obtain an array of F1 hybrid types; seven of the hybrid types spontaneously produced new amphiploid progeny in F2. In sect. Arachnion the parental species and F1s were all diploids and the amphiploids were tetraploid; in sect. Gilia the parental species were diploids or tetraploids and the amphiploids were tetraploid or hexaploid. Two measures were used to express the frequency of spontaneous amphiploid formation. The first is the proportion of the F1 hybrid combinations that yielded any amphiploid progeny at all. In sect. Arachnion this proportion is 3/39 or 7.7%; in sect. Gilia it is 4/16 or 25%. A second measure is needed to express the variation in productivity among the seven amphiploid-producing hybrid types. The measure adopted is the mean number of new amphiploids per single F1 hybrid plant. The productivity numbers for the three hybrid combinations in sect. Arachnion are 0.25, 0.67, and 2.0; and those for four hybrid combinations in sect. Gilia are 0.15, 0.62, 2.25, and 12.62. There are large differences from one hybrid combination to another in rate of amphiploid formation, and the rate is quite high in some hybrids. The factors affecting these differences are discussed.     

Astragalus sect. Trachycercis (Fabaceae) in Iran

A diagnostic key, and new data are provided for seven species of Astragalus sect. Trachycercis , which occur within the area covered by the Flora of Iran. Astragalus brevipedunculatus Ranjbar is described as new, and A. armeniacus Boiss. is reported as new for the flora of Iran. The micromorphology of the seed coat surface of ten Astragalus taxa has been studied by SEM. Considerably different types of sculpturing at species level and similarities between related taxa were observed. In addition, differences between A . sect. Trachycercis and the closely related sections A . sect. Erioceras and A. sect. Wettsteiniana are discussed. Astragalus durandianus , A. pseudoshebarensis and A. shebarensis , which all have strongly inflated pods, are transferred from A . sect. Erioceras to A. sect. Wettsteiniana. Astragalus brevipedunculatus sp. nov., described from a small region near Aras River in Iran, is the only geographically isolated species of the section. Members of the section prefer habitats from coastal dune climates of the Azarbaijan Sharqi Province to the Armenian and Azarbaijan frontiers, although possibly also growing in the adjacent southern parts of Armenia and Azarbaijan. Astragalus brevipedunculatus sp. nov. is the only species of the section in Iran and neighboring countries that has few pairs of leaflets and is completely glabrous. The new species should be considered as a 'Critically Endangered' (CR) following the IUCN criteria. A distribution map for A. brevipedunculatus and A. armeniacus is presented.     

嵩草属植物硅酸体系统的研究

对国产狭义嵩草属 (K obresia,Cyperaceae) 3个组 2 7种植物进行了硅酸体系统分析研究 ,同时结合近缘的苔草属 (Carex) 2个组的植物硅酸体特征 ,深入探讨了植物硅酸体系统分析研究在莎草科苔草族 (Cariceae)中的系统分类学意义。认为 :(1 )嵩草属及其临近类群在属间、种间及种下水平的系统分类学比较研究都可以借助植物硅酸体系统研究的证据。 (2 )穗状嵩草组 (sect. Elyna)的硅酸体系统特征具有较高的一致性 ,除矮嵩草 (K.humilis)及其近缘种同其他穗状嵩草组的种类有所不同 ,它很可能有一个不同于穗状嵩草组其他类群的嵩草组(sect. K obresia)的亲缘。 (3 )从植物硅酸体系统特征的研究来看 ,拟苔草组 (sect. H emicarex)的一些种接近于穗状嵩草组 ,如高山嵩草 (K . pygmeae) ;而另一些种接近于嵩草组 ,如禾叶嵩草 (K . graminifolia) ;也有一些种类的硅酸体系统特征更接近苔草属 ,说明这个组很可能是多源的 ,即本组的单一花穗和果囊形态特征由不同类群的复合花序种类趋同演化而出。(4 )嵩草组的硅酸体系统特征具有较高的一致性 ,说明嵩草属原始类群在硅酸体系统特征方面与外部形态特征演化的某些相关性。     

Distribution of a 375 bp repeat sequence inAllium (Alliaceae) as revealed by FISH

Information about evolutionary relationships between species of the genusAllium is desirable in order to facilitate breeding programmes. One approach is to study the distribution of repetitive DNA sequences among species thought on taxonomic grounds, to be closely related. We have used fluorescent in-situ hybridisation (FISH) to examine seven species within sect.Cepa of the genus (A. altaicum, A. cepa, A. fistulosum, A. galanthum, A. pskemense, A. oschaninii andA. vavilovii), one species from sect.Rhizirideum (A. roylei), two species from sect.Allium (A. sativum andA. porrum) and one species from sect.Schoenoprasum (A. schoenoprasum). Each species was probed using a 375 bp repeat sequence isolated fromA. cepa (Barnes & al. 1985), which was generated and labelled by polymerase chain reaction (PCR). No signals were detected in anyAllium species not belonging to sect.Cepa with the exception ofA. roylei, whose designation in sect.Rhizirideum is now questioned. Within sect.Cepa the probe was found to hybridize to the terminal regions of the chromosome arms of all the species examined. In addition a number of interstitial bands were detected. Use of FISH reveals a more detailed map of the location of the repeat sequences than has previously been obtained by C-banding and other staining procedures. The distribution of the terminal and interstitial sites when compared, allow us to identify three species groups namely,A. altaicum andA. fistulosum; A. cepa, A. roylei, A. oschaninii andA. vavilovii; andA. galanthum andA. pskemense.     

铁线莲属翅果铁线莲组修订

对毛茛科铁线莲属Clematis中单型的翅果铁线莲组sect .Pterocarpa进行了分类学修订,写出了此组及其惟一种,翅果铁线莲C.brachyura的分类学简史和形态描述,给出此种的插图。根据其体态及花构造近似亚洲东部的辣蓼铁线莲C.mandshuricaRupr .和圆锥铁线莲C.ternifloraDC.(二种均为威灵仙组sect .Clematis的成员) ,推测翅果铁线莲可能源自威灵仙组。     

The first record of Astragalus sect. Aegacantha (Fabaceae) in Iran

A new distinct population of Astragalus leiosemius. hitherto unknown to science, is reported for the first time from the eastern Alborz mountains in the Irano-Turanian part of Iran, at an altitude of 2400 m, far disjunct (ca. 800 km) from the populations at the Asia media and Afghanistan. The new taxon is described and illustrated as Astragalus leiosemius subsp. sabzevarensis. This orophilous and tragachantic plant belongs to A. sect. Aegacantha. On the basis of some important data on morphology, ecology and chorology, the new taxon is reported and its affinities and differences with regard to close taxa are presented. A. sect Aegacantha is recorded for the first time from the eastern part Iran.     

The importance of petiole structure on inhabitability by ants in Piper sect. Macrostachys (Piperaceae)

Several Central American species of Piper sect. Macrostachys have obligate associations with ants, in which the ant partner derives food and shelter from modified plant structures and, in turn, protects the plant against fungal infection and herbivory. In addition to these obligate ant-plants (i.e. myrmecophytes), several other species in Piper have resident ants only sometimes (facultative), and still other plant species never have resident ants. Sheathing petioles of sect. Macrostachys form the domatia in which ants nest. Myrmecophytes in sect. Macrostachys have tightly closed petiole sheaths with bases that clasp the stem. These sheathing petioles appear to be the single most important plant character in the association between ants and species of sect. Macrostachys . We examined the structure and variation of petioles in these species, and our results indicate that minor modifications in a small number of petiolar characters make the difference between petioles that are suitable for habitation by ants and those that are not.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 181–191.