Evolution of Piperales--matK gene and trnK intron sequence data reveal lineage specific resolution contrast

Piperales represent the largest basal angiosperm order with a nearly worldwide distribution. The order includes three species rich genera, Piper (ca. 2000 species), Peperomia (ca. 1500-1700 species), and Aristolochia s. l. (ca. 500 species). Sequences of the matK gene and the non-coding trnK group II intron are analysed for a dense set of 105 taxa representing all families (except Hydnoraceae) and all generic segregates (except Euglypha within Aristolochiaceae) of Piperales. A large number of highly informative indels are found in the Piperales trnK/matK dataset. Within a narrow region approximately 500 nt downstream in the matK coding region (CDS), a length variable simple sequence repeat (SSR) expansion segment occurs, in which insertions and deletions have led to short frame-shifts. These are corrected shortly afterwards, resulting in a maximum of six amino acids being affected. Furthermore, additional non-functional matK copies were found in Zippelia begoniifolia, which can easily be discriminated from the functional open reading frame (ORF). The trnK/matK sequence data fully resolve relationships within Peperomia, whereas they are not effective within Piper. The resolution contrast is correlated with the rate heterogeneity between those lineages. Parsimony, Bayesian and likelihood analyses result in virtually the same topology, and converge on the monophyly of Piperaceae and Saururaceae. Lactoris gains high support as sister to Aristolochiaceae subf. Aristolochioideae, but the different tree inference methods yield conflicting results with respect to the relationships of subfam. Asaroideae. In Piperaceae, a clade formed by the monotypic genus Zippelia and the small genus Manekia (=Sarcorhachis) is sister to the two large genera Piper and Peperomia.     

裸蒴属的核型及三白草科四属间系统关系的探讨

本文首次报道三白草科裸蒴属中华裸蒴(Gymnotheca chinensis Decne)和白苞裸蒴(G. involucrata Pei)的染色体数目。两个种的体细胞染色体数均为2n=18,染色体基数为x=9。三白草科原始祖先的染色体基数假定为x=11,裸蒴属可能是经非整倍减少演变而来。裸蒴属间期核型属球状或棒状前染色体型。本文根据三白草科染色体研究的结果和现代地理分布格局,结合其他分枝学科的研究资料,对科下四属间的系统发育关系提出了初步假设。     

Phylogeny of Saururaceae based on mitochondrial matR gene sequence data

DNA sequences of matR gene from three species of Saururaceae and the selected outgroups, Chloranthus holostegius and Zippelia begoniaefolia, are reported. All DNA sequences of six species in four genera of Saururaceae and the two outgroups are analyzed on PAUP 4.0 8b to reconstruct the phylogeny. A single matR gene tree is generated from parsimony, distance, and likelihood analyses, respectively. The three trees with the same topology are slightly different in bootstrapping support for some clades. The result indicates that Saururaceae is monophyletic. Anemopsis is sister to Houttuynia, and the two genera form the first diverging lineage of the family. The sister group relationship between Saururus and Gymnotheca is also supported by a relatively high bootstrap value. The result is different from all the former phylogenetic opinions on Saururaceae based on morphology, but it is supported by the evolution of flower-bract stalk in Saururaceae. In addition, some characteristics of the matR gene are analyzed. The MatR gene is a relatively better tool to reconstruct the molecular clock because the base substitution bias greatly decreases in the gene.     

三白草科花部发育及其系统学意义

本研究从比较三白草科属间小花个体发育及分析花器官数量变异入手,探寻花器官在发生顺序、数目变化及排列方式等方面的演化趋势,揭示系统发育在个体发育中一定程度重现的事实及属间的进化关系。结果简述如下:首先,雄蕊和心皮发生顺序由中部优先演化到两侧优先。其次,由于远中雄蕊和心皮经历了从发育延迟、生长减缓到最终消失的历程,中部雄蕊和心皮由成对演化为单生。此外,两侧生雄蕊对由各自独立的原基发生演化到共同原基发生或减化为1枚,假银莲花属近中1枚雄蕊原基二裂成1对,蕺菜属3枚心皮发生于一环状共同原基等,都是该科花器官演化的重要事实并可归结为融合、减化和复化的结果。文章根据花器官的演化趋势及过渡类型的剖析,论述了三白草科属间的系统进化关系。     

Floral ontogeny of Zippelia begoniaefolia and its familial affinity: Saururaceae or Piperaceae?

Zippelia begoniaefolia Bl., a monotypic species having characteristics of both Piperaceae and Saururaceae, has racemes of about 20 small flowers lacking a perianth, each with six free stamens and a four-carpellate syncarpous gynoecium. The inflorescence apical meristem initiates bracts acropetally and helically, each of which subtends a later initiated single floral apex; there are no “common” primordia. The six stamens are initiated as two lateral pairs and two solitary successive primordia, the latter two opposite in median sagittal positions. Four carpel primordia are initiated as a lateral pair and two successively initiated in the median sagittal plane. This order of organ inception is unique among Piperaceae and Saururaceae. Intercalary growth below carpellary attachment raises them up on a common cylindrical base that becomes the syncarpous ovary, covered with unique glochidiate hairs and containing a single basal ovule. The free portions of the carpels become the reflexed papillate stigmas. The floral vascular system has a single bundle at base that branches to supply the bract and flower traces. The floral vasculature is similar but not identical to that of Saururus (Saururaceae) and some Piper species (Piperaceae). Plesiomorphic character states of Zippelia that are shared with Saururus include hypogyny, free stamens, cleft stigma, and a similar floral groundplan. Synapomorphies, derived shared character states that unite Zippelia with Piperaceae, include syncarpy, solitary ovule, basal placentation, fused ventral carpellary bundles, and a double vascular cylinder in the stem. Cladistic analysis aligns Zippelia with Piperaceae because they share apomorphies, and because Zippelia shares only plesiomorphies with Saururus.     

胡椒科的花粉形态及其分类学意义

胡椒科的某些属之间,花粉形态表现出一定的差异。齐头绒属花粉粒表面粒为平滑,但有小穿孔,略显粗糙。胡椒属的花粉粒表面有不规则的瘤状纹饰,纹饰较为平滑。Ｌｅｐｉａｎｔｈｅｓ（Ｐｏｔｈｏｍｏｒｐｈｅ）的花粉粒表面瘤状纹饰不显著。     

Multilayered structure of tension wood cell walls in Salicaceae sensu lato and its taxonomic significance

Salicaceae have been enlarged to include a majority of the species formerly placed in the polyphyletic tropical Flacourtiaceae. Several studies have reported a peculiar and infrequently formed multilayered structure of tension wood in four of the tropical genera. Tension wood is a tissue produced by trees to restore their vertical orientation and most studies have focused on trees developing tension wood by means of cellulose‐rich, gelatinous fibres, as in Populus and Salix (Salicaceae s.s.). This study aims to determine if the multilayered structure of tension wood is an anatomical characteristic common in other Salicaceae and, if so, how its distribution correlates to phylogenetic relationships. Therefore, we studied the tension wood of 14 genera of Salicaceae and two genera of Achariaceae, one genus of Goupiaceae and one genus of Lacistemataceae, families closely related to Salicaceae or formerly placed in Flacourtiaceae. Opposite wood and tension wood were compared with light microscopy and three‐dimensional laser scanning confocal microscopy. The results indicate that a multilayered structure of tension wood is common in the family except in Salix, Populus and one of their closest relatives, Idesia polycarpa. We suggest that tension wood may be a useful anatomical character in understanding phylogenetic relationships in Salicaceae. Further investigation is still needed on the tension wood of several other putatively close relatives of Salix and Populus, in particular Bennettiodendron, Macrohasseltia and Itoa.     

CARRAGEENANS FROM AUSTRALIAN REPRESENTATIVES OF THE FAMILY CYSTOCLONIACEAE (GIGARTINALES, RHODOPHYTA), WITH DESCRIPTION OF CALLIBLEPHARIS CELATOSPORA SP. NOV., AND TRANSFER OF AUSTROCLONIUM TO THE FAMILY ARESCHOUGIACEAE

Ten Australian representatives from seven of the 10 genera presently constituting the family Cystocloniaceae have been analyzed for their cell-wall galactans. Included in our survey are the monotypic Australian-endemic genera Austroclonium , Gloiophyllis , Erythronaema , and Stictosporum , one species of Craspedocarpus , three species of Rhodophyllis , and two species of Calliblepharis . As one of the species of the latter genus is endemic to Western Australia and presently undescribed, we illustrate its habit and anatomical features in formally proposing to name it Calliblepharis celatospora Kraft, sp. nov. All the species surveyed essentially produce typical iota (ι)-carrageenans, with the exception of Austroclonium . The sulfated galactans from Austroclonium predominantly contain the repeating units of ι-, alpha (α)-, and 6'-O-methylated ι- and α-carrageenans; whether these exist as discrete polysaccharides or a complex hybrid structure was not resolved. Thus, Austroclonium carrageenans resemble the polysaccharides from Rhabdonia , Areschougia , and Erythroclonium . Although these latter three genera are currently included in the large gigartinalean family Solieriaceae, all produce significantly different carrageenans from Solieria itself and related genera such as Eucheuma , Kappaphycus , Betaphycus , Sarcodiotheca , Agardhiella , Sarconema , and Callophycus . In consideration of these findings, as well as of significant anatomical similarities, we provisionally recommend reestablishment of the family Rhabdoniaceae Kylin (as the family Areschougiaceae J. Agardh) for Rhabdonia , Areschougia , Erythroclonium , and Austroclonium.     

THE ISOCITRIC ACID CONTENT OF CRASSULACEAN PLANTS AND A FEW SUCCULENT SPECIES FROM OTHER FAMILIES

Soderstrom , Thomas R. (Smithsonian Institution, Washington, D.C.) The isocitric acid content of crassulacean plants and a few succulent species from other families. Amer. Jour. Bot. 49(8): 850–855. 1962.—The leaves of 58 species of plants were assayed for isocitric acid content by the highly specific enzymatic method of Grafflin and Ochoa (1950). These species included 39 from the family Urassulaceae in addition to 19 species of succulents representing 8 families and 12 genera. With but one exception (Echeveria derenbergii), isocitric acid was found in relatively large concentrations in the leaves of all crassulacean species examined, and was recorded for the first time in 5 genera of this family. Isocitric acid was found in 2 genera of the Liliaceae and in 1 genus of the Piperaceae, families in which it previously had not been known to occur. The presence of substantial concentrations of isocitric acid in the leaves appears to be characteristic of the family Crassulaceae and of certain genera in other widely unrelated families. There is no indication, however, that the concentrations of this acid in the leaves of species and genera of the Crassulaceae is correlated with their affinities based on morphology.     

Hidden generic diversity in Neotropical birds: molecular and anatomical data support a new genus for the "Scytalopus"indigoticus species-group (Aves: Rhinocryptidae)

The genus Scytalopus is a species-rich and taxonomically complicated component of the Neotropical avian family Rhinocryptidae. Probably because Scytalopus is a superficially uniform assemblage, its monophyly has not been seriously questioned. We investigated phylogenetic relationships of a representative set of species in the genus using nuclear and mitochondrial DNA sequences as well as anatomical data, and provided the first test of its presumed monophyly by including in the analyses its hypothesized closest relatives (the genera Myornis, Eugralla, and Merulaxis) as well as most rhinocryptid genera. We found strong support for the paraphyly of the genus Scytalopus, with the Scytalopus indigoticus species-group forming a clade with Merulaxis. A well-supported clade including the genera Eugralla, Myornis, and the remaining Scytalopus was also recovered. Because these results were recovered independently and with strong support using mitochondrial and nuclear data, and were entirely consistent with anatomical data, we erect a new genus for the S.indigoticus species-group. These findings illustrate the importance of formally testing hypotheses of monophyly even for well-accepted groups of Neotropical birds.     

陕西胡椒科一新记录属--胡椒属

报道了陕西省胡椒科一新记录属——胡椒属(Piper Linn．)及一新记录种——竹叶胡椒(P．bambusifolium Y．C．Tseng)。     

Phylogenetic relationships of the genus Frenkelia: a review of its history and new knowledge gained from comparison of large subunit ribosomal ribonucleic acid gene sequences.

The different genera currently classified into the family Sarcocystidae include parasites which are of significant medical, veterinary and economic importance. The genus Sarcocystis is the largest within the family Sarcocystidae and consists of species which infect a broad range of animals including mammals, birds and reptiles. Frenkelia, another genus within this family, consists of parasites that use rodents as intermediate hosts and birds of prey as definitive hosts. Both genera follow an almost identical pattern of life cycle, and their life cycle stages are morphologically very similar. However, the relationship between the two genera remains unresolved because previous analyses of phenotypic characters and of small subunit ribosomal ribonucleic acid gene sequences have questioned the validity of the genus Frenkelia or the monophyly of the genus Sarcocystis if Frenkelia was recognised as a valid genus. We therefore subjected the large subunit ribosomal ribonucleic acid gene sequences of representative taxa in these genera to phylogenetic analyses to ascertain a definitive relationship between the two genera. The full length large subunit ribosomal ribonucleic acid gene sequences obtained were aligned using Clustal W and Dedicated Comparative Sequence Editor secondary structure alignments. The Dedicated Comparative Sequence Editor alignment was then split into two data sets, one including helical regions, and one including non-helical regions, in order to determine the more informative sites. Subsequently, all four alignment data sets were subjected to different tree-building algorithms. All of the analyses produced trees supporting the paraphyly of the genus Sarcocystis if Frenkelia was recognised as a valid genus and, thus, call for a revision of the current definition of these genera. However, an alternative, more parsimonious and more appropriate solution to the Sarcocystis/Frenkelia controversy is to synonymise the genus Frenkelia with the genus Sarcocystis.     

A new taxonomy of the family Teloschistaceae

The lichen family Teloschistaceae is one of the larger families of lichenized fungi. Currently it includes one very large heterogenous genus, Caloplaca, with some 1000 or more species with a vast variation in morphology, anatomy and chemistry. The rest of the family is split into 10–15 smaller genera, each with 20 or fewer species. There is no modern classification of the family based on molecular data. Here we attempt a first phylogenetic evaluation of a large part of the family, including a total of 337 species. Of these, 162 were used in a combined phylogenetic analysis of the ribosomal RNA sequence markers nrITS, nrLSU and mrSSU, using Bayesian inference. We also analysed all species using nrITS data, split into four different analyses. As a result we propose a new classification of the family, where a total of 39 genera are recognized, of which 31 are newly described or resurrected. The new genera are: Athallia, Austroplaca, Bryoplaca, Calogaya, Cerothallia, Flavoplaca, Gondwania, Haloplaca, Orientophila, Pachypeltis, Parvoplaca, Rufoplaca, Shackletonia, Scutaria, Sirenophila, Solitaria, Squamulea, Stellarangia, Teloschistopsis, Usnochroma, Variospora, Villophora and Wetmoreana. Resurrected genera are Blastenia, Dufourea, Follmannia, Gyalolechia, Leproplaca, Polycauliona, Pyrenodesmia and Xanthocarpia. The species Orientophila subscopularis is described as new. A third subfamily, Teloschistoideae, is proposed to accommodate the genus Teloschistes and related genera, parallel to the two previously recognized subfamilies Xanthorioideae and Caloplacoideae. We also show the large plasticity in both morphological and anatomical characters between closely related species within genera, indicating the low value of these as evolutionary markers. The secondary chemistry is a better marker in some parts of the family. We recognize a large number of geographically delimited clades with clear centres of evolution, but often showing large variation in morphology and anatomy.     

Kritische Revision der „Thlaspi”︁-Arten Europas,Afrikas und Vorderasiens I. Geschichte,Morphologie und Chorologie

In the general introduction of a taxonomical revision of the genus Thlaspi L. from Europa, the Near East and Africa — a conspectus of the species till now comprised within this genus has already been published — a historical survey of the genus Thlaspi is given. Morphological resp. anatomical characters have been judged. The structure of the seedtesta inter alia exhibited a different pattern which proved to be valuable for differentiation. In Thlaspi s. str. this pattern revealed to be well distinguishable from all the other Thlaspi-species hitherto put in this genus; thus showing Thlaspi s. str. a species-complex of its own. The characteristical differences of the numerous species out of the Thlaspi s. str.-complex allow further separation of different genera, so that the hitherto existing genus Thlaspi has been found to be a mosaic of different genera. The degree of their closer or wider relationship, however, could be investigated after extensive studies in different genera of the Brassicaceae (Cruciferae). A subordination of these complexes of closer relationship as subgenera of the genus Thlaspi is impossible, because the morphological and anatomical differences are too great. A persistency in the hitherto scope of a heterogenous genus Thlaspi is considered unreasonable and would encourage a greater humping of many genera within the family Brassicaceae which are well separated till now. This would not reflect the natural conditions. Additional figures of fruits and seedtestas of different species support this view. Finally the geographical distribution of the several genera has been described which in Noccaea Moench shows shortly the wide extension of this genus throughout northern Asia and the extratropical America.     

中国木兰科各属次生木质部的解剖特征及系统演化

综述了中国木兰科10属的次生木质部解剖学特征,包括导管分子,纤维管胞和木射线。同时,进一步讨论了其系统演化。这10属分为两亚科,即:木兰亚科(Magnoliodeae),包括木兰族(Magnolieae)和含笑族(Michelieae Law),木兰族有木莲属(Maglietia Bl.)、华盖木属(Manglietiastrum Law)、木兰属(Magnolia L.)、拟单性木兰属(Parakmeria Hu et Cheng)、单性木兰属[Kmeria(Pierre) Dandy]、长蕊木兰属(Alcimandra Dandy)共六属;含笑族有含笑属(Michelia L.)、合果木属(Paramichelia Hu)、观光木属(Tsoongiodendron Chun)共三属。鹅掌楸亚科[Liriodendroideae(Bark) Law],仅鹅掌楸属(Liriodendron L.)一属。大量的木材解剖学研究表明,木兰科的原始性很明显,但也有一些进化特征。可以通过属间的差别来分析本科的系统演化。木兰科的系统演化可简单总结为:木兰亚科[木兰族(木莲属,华盖木属,拟单性木兰属,单性木兰属→木兰属,长蕊木兰属)→含笑族]→鹅掌楸亚科。     

From Forgotten Taxon to a Missing Link? The Position of the Genus Verhuellia (Piperaceae) Revealed by Molecules

BACKGROUND AND AIMS: The species-poor and little-studied genus Verhuellia has often been treated as a synonym of the genus Peperomia, downplaying its significance in the relationships and evolutionary aspects in Piperaceae and Piperales. The lack of knowledge concerning Verhuellia is largely due to its restricted distribution, poorly known collection localities, limited availability in herbaria and absence in botanical gardens and lack of material suitable for molecular phylogenetic studies until recently. Because Verhuellia has some of the most reduced flowers in Piperales, the reconstruction of floral evolution which shows strong trends towards reduction in all lineages needs to be revised. METHODS: Verhuellia is included in a molecular phylogenetic analysis of Piperales (trnT-trnL-trnF and trnK/matK), based on nearly 6000 aligned characters and more than 1400 potentially parsimony-informative sites which were partly generated for the present study. Character states for stamen and carpel number are mapped on the combined molecular tree to reconstruct the ancestral states. KEY RESULTS: The genus Peperomia is generally considered to have the most reduced flowers in Piperales but this study shows that this is only partially true. Verhuellia, with almost equally reduced flowers, is not part of or sister to Peperomia as expected, but is revealed as sister to all other Piperaceae in all analyses, putting character evolution in this family and in the perianthless Piperales in a different light. A robust phylogenetic analysis including all relevant taxa is presented as a framework for inferring patterns and processes of evolution in Piperales and Piperaceae. CONCLUSIONS: Verhuellia is a further example of how a molecular phylogenetic study can elucidate the relationships of an unplaced taxon. When more material becomes available, it will be possible to investigate character evolution in Piperales more thoroughly and to answer some evolutionary questions concerning Piperaceae.     

Placing the origin of two species-rich genera in the late cretaceous with later species divergence in the tertiary: a phylogenetic, biogeographic and molecular dating analysis of Piper and Peperomia (Piperaceae)

Nearly all of the species diversity in Piperaceae is encompassed within Piper and Peperomia. Both genera are pan-tropical with areas of diversification in the Neotropics and Southeast Asia. Piperaceae are less diverse in Africa with only two native species of Piper. This study examines the distribution of both Piper and Peperomia with representative samples from the Neotropics, Asia, Pacific Islands, and Africa. Molecular dating is used to place an age for the crown clades of Piper and Peperomia as well as ages for diversification within the clades. Both genera have origins in the late Cretaceous, but species level diversification occurred much later in the Tertiary. Biogeography of both genera are correlated with paleoclimate evidence to better explain the distribution and diversification of these large genera.