Table of Contents

01 March 2018, Volume 56 Issue 2
Cover illustration: Stephania fossil endocarps from eastern Asia and western North America. From left to right, top to bottom: Stephania jacquesii sp. nov. from Oligocene of Guangxi, China; CT scan of S. jacquesii from Guangxi; Stephania jacquesii sp. nov. from late Eocene of Oregon, USA; CT scan of S. jacquesii from Oregon; Stephania wilfii sp. nov. from early Eocene of Wyoming, USA. See Han et al., pp. 81–91 in this issue. The cover image was prepared by Meng H [Detail] ...
  • Song Ge and Jun Wen
    J Syst Evol. 2018, 56(2): 79-80.
  • Research Articles
  • Meng Han, Steven R. Manchester, Qiong-Yao Fu, Jian-Hua Jin, Cheng Quan
    J Syst Evol. 2018, 56(2): 81-91.
    Stephania Loureiro is a large genus within Menispermaceae, with approximately 60 extant species naturally distributed in tropical to subtropical areas in Asia and Africa, and a few in Oceania. This genus possesses highly characteristic endocarps that facilitate identification of extant and fossil specimens. Here, we report some well-preserved fossil fruits of Stephania from North America and East Asia. The specimens indicate the endocarps were bony or woody with an obovate to obovate-rotund outline and a horseshoe-shaped locule. The endocarp length varies from 4.7 to 8.3 mm, and width from 3.7 to 7.0 mm. The endocarp has a clear foramen in the central area and is surrounded by a keel with ribs running along the dorsal surface. Only one lateral crest develops on each side of the endocarp. Two new species are recognized: Stephania wilfii Han & Manchester sp. nov. from the Paleocene to Eocene of Wyoming (USA), and Stephania jacquesii Han & Manchester sp. nov. disjunct between the late Eocene of Oregon (USA) and the late Oligocene of Guangxi Province (China). In addition, on the basis of more detailed morphological comparative analyses, we transfer the fossils formerly treated as Diploclisia auriformis (Hollick) Manchester from the early Eocene of London Clay, and the middle Eocene of Alaska and Oregon to Stephania auriformis (Hollick) Han & Manchester comb. nov. These fossil materials indicate a broader biogeographic distribution for the ancestors of extant Stephania lineages. This finding enhances our knowledge of the taxonomic and morphological diversity of Stephania and provides new evidence concerning its phytogeographic history.
  • Wei Cang, Yu-xin Sheng, Ejiroghene Ruona Evivie, Wen-wen Kong, Jing Li
    J Syst Evol. 2018, 56(2): 92-104.
    Glucosinolates, a class of specialized metabolites specific to the order Brassicales, have diverse bioactivities that are largely dependent on the structures of their side chains. Flavin-containing monooxygenases (FMOs) encoded by the FMOGS-OX genes have been found to catalyze side-chain modifications during the synthesis of methionine-derived aliphatic glucosinolates. Seven FMOGS-OX genes have been identified in Arabidopsis Heynh., but the evolution of these genes in the Brassicaceae, a family including many economically important vegetables, is poorly understood. In this study, the phylogenetic and syntenic relationships of theFMOGS-OX genes belonging to 12 sequenced Brassicaceae species were analyzed. Our results showed that the FMOGS-OX genes included two tandem arrays, theFMOGS-OX2-4 group (group A) and the FMOGS-OX5-7 group (group B). The evolutionary histories of the FMOGS-OX groups A and B were similar across the Brassicaceae, but two lineage-specific evolutionary routes developed after these two separate species lineages diverged from Aethionema arabicum (L.) Andrz. ex DC. In the lineage I route, FMOGS-OX gene copies tended to increase due to frequent tandem duplication events in most species and a whole genome triplication in Camelina sativa (L.) Crantz. In the lineage II route, gene copies decreased due to deletion events. Combining these results with those of previous studies, we speculated that the FMOGS-OX genes were derived from an ancestral gene with a broad expression distribution and a broad range of substrates, which then underwent subfunctionalization to generate progeny limited in either spatial expression or substrate structure. Furthermore, the absence of FMOGS-OX5 substrates in some FMOGS-OX5-containing species may suggest neofunctionalization of these genes.
  • Ying-Xia Lei, Jia Liu, Xing Fan, Li-Na Sha, Yi Wang, Hou-Yang Kang, Yong-Hong Zhou, Hai-Qin Zhang
    J Syst Evol. 2018, 56(2): 105-119.
    Roegneria C. Koch is a relatively large polyploid perennial genus with 130 species in the Triticeae, and consisting of the St and Y genomes. There are different opinions about whether Roegneria is an independent genus, or whether it should be included in the genus Elymus L. For many species of Roegneria, their genome constitution and phylogenetic relationship are still unknown. More research about the maternal genome donor of the Roegneria species is needed. To investigate the phylogenetic relationships and maternal genome donor of Roegneria and its affinitive genera, phylogenetic analyses of two chloroplast regions ndhF and trnH–psbA sequences were carried out in this study. The results showed that: (i) Campeiostachys Drobow (StYH) and all Roegneria (StY, StStY) species were scattered with Pseudoroegneria Á. Löve (St) species; (ii) R. sinica Keng, R. schugnanica (Nevski) Nevski, R. seriotina Keng, and Elymus calcicolus (Keng) Á. Löve containing the St genome; (iii) there was differentiation among species of Pseudoroegneria; and (iv) the St genome in diploid, tetraploid, and hexaploid species are divergent. Thus, it is suggested that: (i) Pseudoroegneria served as the maternal genome donor of Roegneria, including four species with unknown genomic constitutions (R. sinica, R. schugnanica, R. seriotina, and E. calcicolus); (ii) species of Roegneria or Pseudoroegneria might serve as the maternal genome donor of Campeiostachys; and (iii) the St genome has undergone differentiation during polyploidization in diploid, tetraploid, and hexaploid species.
  • Paola Jara-Arancio, Paula M. Vidal, Mary T. K. Arroyo
    J Syst Evol. 2018, 56(2): 120-128.
    The genus Triptilion is endemic to central Chile, the Mendoza Province and western Patagonia in Argentina. It is currently composed of seven species: T. achilleae, T. benaventii, T. berteroi, T. capillatum, T. cordifolium, T. gibbosum, and T. spinosum. The main objectives of this paper were to determine the phylogenetic relationships of species of Triptilion. We also traced the evolution of annual and perennial life-forms. Historically a close relationship has been described between genera Triptilion and Nassauvia. Phylogenetic analysis of the genus Triptilion and more closely related genera was undertaken using two nuclear (ITS, ETS) and two chloroplast (trnL-F, rpl32-trnL) markers. The topology of the Bayesian inference tree shows that the genus Triptilion is paraphyletic, because Nassauvia lagascae, the only representative of Nassauvia section Caloptilium grouped with T. achilleae, Clade I. The other species of Triptilion form two clades: Clade II composed of T. cordifolium and T. gibbosum and Clade III that includes T. benaventii, T. berteroi, T. capillatum, and T. spinosum. The genus Triptilion originated and diverged during the Miocene. The results of the life history reconstructions indicate that the common ancestor of Triptilion and Nassauvia was perennial. The annual habit appears to be derived in Triptilion. The life-form of the common ancestor of Triptilion was ambiguous; it may have been annual or perennial.
  • Lei Huang, Fang-Dong Geng, Jing-Jing Fan, Cheng Xue, Xiao-Yan Zhang, Ju-Qing Kang, Jian-Qiang Zhang, Yi Ren
    J Syst Evol. 2018, 56(2): 129-138.
    The genus Aquilegia is emerging as the new model system for plant development, ecology, and evolution studies. Previous research showed that pollinator shift might drive the diversification of North American Aquilegia species, and natural selection on the length of petal nectar spur might play a crucial role. In this genus, A. ecalcarata Maxim. is the only taxon that has lost nectar spurs. Previous phylogenetic results indicated that A. ecalcarata, A. yabeana Kitag., A. oxysepala var. kansuensis Bruhl., and A. rockii Munz comprised a monophyletic group. However, their pattern of genetic diversity remains unknown. In addition, little is known about the evolutionary relationship among the four species on the population level. We carried out a population genetics study with 21 representative populations based on 10 single-copy nuclear gene fragments and found that: (i) A. yabeana conserved the highest genetic diversity (both πsil and θsil) and A. oxysepala var. kansuensis had the lowest level; (ii) A. ecalcarata split into two groups, with one population clustered with A. rockii and the other five populations clustered with A. oxysepala var. kansuensis; and (iii) the allele frequency spectrum showed an excess of low frequency alleles in all four species, implying that they may undergo the mutation-drift equilibrium. Our findings provide the first investigation of genetic diversity and evolutionary relationships in A. yabeana, A. oxysepala var. kansuensis, A. rockii, and A. ecalcarata. They lay the foundation for future evolutionary studies, such as speciation mediated by pollinators.
  • Shi-Yong Dong, Cheng-Wei Chen, Shi-Shi Tan, Hui-Guo Zhao, Zheng-Yu Zuo, Yi-Shan Chao, Yi-Han Chang
    J Syst Evol. 2018, 56(2): 139-147.
    The fern genus Tectaria (Tectariaceae) Cav. is morphologically diverse and difficult in terms of recognizing species and species groups. To infer the systematic positions of some species and identity-unknown collections with special morphological characters, we undertook phylogenetic analyses based on sequences of five plastid regions (atpB, ndhF + ndhF-trnL, rbcL, rps16-matK + matK, and trnL-F). Three analysis methods (maximum parsimony, maximum likelihood, and Bayesian inference) were used to reconstruct the phylogeny of Tectaria. The most surprising result is that T. menyanthidis (C. Presl) Copel., T. ternata (Baker) Copel., and T. variabilis Tardieu & Ching are revealed to represent a distinct lineage from Tectaria, which should be called Polydictyum C. Presl, and is supported as sister to Pteridrys C. Chr. & Ching. Other accessions of Tectaria are well resolved into four major clades, which is consistent with the results of previous studies. Of the four clades, Clade II (T. subtriphylla (Hook. & Arn.) Copel. group) is unpredictable, with morphologically very diverse species clustered there, and is supposed to be a minor evolutionary line within Tectaria in the Old World. In addition, the position of the climbing genus Arthropteris J. Sm. and the utility of molecular data in recognizing species of Tectaria are briefly discussed. As a conclusion, we formally reinstate the genus Polydictyum by providing diagnostic characters, key to species, nomenclature, and information of detailed distribution and habitat for the currently known three species.
  • Xin-Mao Zhou, Liang Zhang, Ngan Thi Lu, Xin-Fen Gao, Li-Bing Zhang
    J Syst Evol. 2018, 56(2): 148-173.
    We undertook phylogenetic analyses to resolve the relationships of Pteridrys and related taxa based on six plastidmarkers (atpA, atpB, matK& rps16-matK, rbcL, rps4& rps4-trnS, and trnL & trnL-F) and nuclear pgiC.We included 195 accessions representing approximately 147 species in 38 genera, and seven of the nine families in Polypodiineae (eupolypods I). Tectariaceae s.l. (i.e., Arthropteris, Draconopteris, Hypoderris, Malaifilix, Pteridrys, Tectaria, and Triplophyllum in addition to Polydictyum) is recovered asmonophyletic (97% maximum likelihood bootstrap value), but with low (<50%) maximum parsimony jackknife value. The family Tectariaceae s.l. is therefore the only family in ferns without a corresponding non-parametric-based strong support in spite of our data totaling 9616 aligned base pairs. Tectariaceae s.l. can not be unambiguously recognized by any of the 13morphological characters analyzed. However, if the clade composed of Draconopteris, Malaifilix, Polydictyum, and Pteridrys (DMPP) is recognized as a distinct family, at least four morphological characters enable the distinction of the DMPP clade from its sister clade. Considering the uncertainty in the monophyly, the diagnosability, and the deep divergence, we propose to establish a new family, Pteridryaceae, to accommodate the DMPP clade. Species of Pteridryaceae share mostly the following characteristics: erect to suberect rhizomes, reduced basal pinnae, anastomosing or free venation, absence of catenate hairs at the leaf surface, and perine ornamentation lacking spines or spinules. Identification keys are provided for the four genera and 31 species of the DMPP clade (or Pteridryaceae). Reflecting the presented results, the recognition of Arthropteridaceae is the preferred taxonomic status of the Arthropteris clade.