Table of Contents

12 January 2018, Volume 56 Issue 1

Cover illustration: Diversity of wild pears. Top left: Pyrus fedorovii in habitat (Prov. Vayotz Dzor, Herher gorge, Armenia). Top right: Flowers of P. spinosa. Bottom left: P. salicifolia (middle) and P. caucasica in habitat (Mtsheta-Mtianeti, Georgia). Bottom right: fruits of a P. salicifolia X P. demetrii hybrid. Photographs by Gerald Parolly. See Korotkova et al., pp. 35–47 in this issue.

  

Review
• A ribonucleopeptide world at the origin of life

  Nizar Y. Saad

  J Syst Evol. 2018, 56(1): 1-13.
  https://doi.org/10.1111/jse.12287

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  The structural flexibility of RNA and its ability to store genetic information has led scientists to postulate that RNA could be the key molecule for the development of life on Earth, further leading to formulate the RNA world hypothesis that received a lot of success and acceptance after the discoveries of the last thirty-five years. Despite its highly structural and functional significance, the difficulty in synthesizing the four nucleobases that form the RNA polymer from the same primordial soup, its low stability, and limited catalytic repertoire, make the RNA world hypothesis less convincing even though it remains the best explanation for the origin of life. An increasing number of scientists are becoming more supportive of a more realistic approach explaining the appearance of life. In this review, I propose an enhanced explanation for the appearance of life supported by recent discoveries and theories. Accordingly, amino acids and peptides associated with RNA (e.g., ribonucleopeptides) might have existed at the onset of RNA and might have played an important role in the continuous development of self-sustaining biological systems. Therefore, in this review, I cover the most recent and relevant scientific investigations that propose a better understanding of the ribonucleopeptide world hypothesis and the appearance of life. Finally, I propose two hypotheses for a primitive translation machinery (PTM) that might have been formed of either a T box ribozyme or a ribopolymerase.
Research Articles
• Anatomy, microstructure, and endogenous hormone changes in Gnetum parvifolium during anthesis

  Qian Lan, Jian-Feng Liu, Sheng-Qing Shi, Nan Deng, Ze-Ping Jiang, Er-Mei Chang

  J Syst Evol. 2018, 56(1): 14-24.
  https://doi.org/10.1111/jse.12263

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  The study of the sexual systems of plants is very important for understanding their evolutionary process. Gnetum is a pivotal species in comprehending the seed plant phylogeny. However, the sexual systems of this genus are not fully understood. To investigate the sexual system of Gnetum, the anatomical structure, microstructure, and endogenous hormones were investigated from the differentiation of flower buds to fertilization in the floral organs of female and male of G. parvifolium (Warb.) C.Y. Cheng, widely distributed in the north of China. After 2 years of field investigations, the staminate strobili were observed on female plants for the first time and the abortive ovules were also found on male plants. In addition, high levels of gibberellin A₃ and zeatin riboside led to masculinization, whereas a high level of indole-3-acetic acid favored feminization. A comprehensive analysis of the results indicates that G. parvifolium may not be completely dioecious on morphology, but female and male plants can only perform their own gender function, which would provide a better understanding of the diversity of sexual systems in Gnetum, and reproductive structures of seed plants.
  
• Differential diversifications of South American and Eastern Asian disjunct genera Bocconia and Macleaya (Papaveraceae)

  Jianhua Li, K. Gregory Murray, Pan Li, Kenneth Brown

  J Syst Evol. 2018, 56(1): 25-34.
  https://doi.org/10.1111/jse.12286

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  Bocconia (10 species) and Macleaya (2 species) are two disjunct genera between South America and eastern Asia (EAS) in the Papaveraceae offering an opportunity to compare its biogeographic history with that of the well-known disjunction between EAS and eastern North American (ENA). Our phylogenetic analyses of the chloroplast matK and rbcL gene sequences of Ranunculales including two species of Macleaya and six species of Bocconia supported the monophyly of Bocconia, Macleaya, and Chelidonioideae to which Bocconia and Macleaya belong. Nucleotide sequences of matK, rbcL, and nrDNA ITS supported the sister relationship of Bocconia and Macleaya. Biogeographic analyses of Chelidonioideae using S-DIVA (statistical dispersal vicariance analysis) and DEC (dispersal extinction cladogenesis) methods inferred Eurasia as the most likely ancestral area of Bocconia and Macleaya and suggested no extinction events in either Bocconia or Macleaya. This agrees with the “Out-of-Asia” pattern of the EAS-ENA disjunction. Molecular dating of Ranunculales with fossil-based calibrations showed that Bocconia and Macleaya diverged in the late Eocene and early Oligocene, which is much earlier than most EAS-ENA disjunct taxa. The disjunction may have formed via long distance dispersal or boreotropical connections via the North Atlantic and Bering land bridges. Both Bocconia and Macleaya diversified in the late mid-Miocene, but Bocconia has apparently experienced a greater diversification probably aided by the evolution of the bird dispersal syndrome in fruit and seed after migration to South America. The greater diversification of Bocconia is also evidenced by the diverse leaf morphology and growth habit in response to colonization in various local habitats in South America.
• Towards resolving the evolutionary history of Caucasian pears (Pyrus, Rosaceae)—Phylogenetic relationships, divergence times and leaf trait evolution

  Nadja Korotkova, Gerald Parolly, Anahit Khachatryan, Lusine Ghulikyan, Harutyun Sargsyan, Janna Akopian, Thomas Borsch, Michael Gruenstaeudl

  J Syst Evol. 2018, 56(1): 35-47.
  https://doi.org/10.1111/jse.12276

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  With approximately 25 endemic species, the genus Pyrus (pears) is highly diverse in the Caucasus ecoregion. The majority of Caucasian pears inhabit xerophytic open woodlands or similar habitats, to which they display morphological adaptations, such as narrow leaves. The other species, both Caucasian and non-Caucasian taxa, mainly inhabit mesophytic forests and display broad leaves. Using a representative taxon sampling of Pyrus from the Caucasus, Europe and Asia, we reconstruct phylogenetic relationships in the genus based on multiple plastid regions. We also estimate the divergence times of major clades in Pyrus, reconstruct the evolution of leaf shapes, and discuss the emergence of xeromorphic leaf traits. Our results confirm the monophyly of Pyrus and the existence of two major clades: (a) an E Asian clade with a crown group age of 15.7 (24.02–8.37 95% HPD) My, and (b) a W Eurasian clade that comprises species from Europe, SW Asia and the Caucasus and that displays a slightly younger crown group of 12.38 (19.02–6.41 95% HPD) My. The existing infrageneric classification of Pyrus was found partially incongruent with the inferred phylogenetic trees. Several currently accepted species were not recovered as monophyletic, indicating that current species limits require re-evaluation. Ancestral character state reconstructions revealed several independent transitions from broad- to narrow-shaped leaves in Pyrus, probably via intermediate-shaped leaves.
• Phylogenetic placement of Yunnanopilia (Opiliaceae) inferred from molecular and morphological data

  Liu Yang, Guan-Song Yang, Hai-Ying Ma, Yue-Hua Wang, Shi-Kang Shen

  J Syst Evol. 2018, 56(1): 48-55.
  https://doi.org/10.1111/jse.12285

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  Yunnanopilia longistaminea (W.Z. Li) C.Y. Wu & D.Z. Li, which is a controversial species in Opiliaceae, is treated as a variety of Champereia manillana (Blume) Merrill in the Flora of China and morphological analysis has produced conflicting results regarding its affinity to Melientha and Champereia. To determine the systematic position of Yunnanopilia in Opiliaceae, we selected two nuclear regions (internal transcribed spacer [ITS4-ITS5] and 18S rDNA) and four chloroplast regions (rbcL, matK, psbA-trnH, and trnS-trnG) to test the phylogenetics of the family Opiliaceae using maximum likelihood and Bayesian inference analysis. Morphological characteristics were also examined to clarify the similarities and differences among Y. longistaminea and two closely related species. Agonandra was located at the basal position in the family Opiliaceae; in the large clade including other remaining genera, two main clades were clearly identified and correlated with inflorescence morphological characteristics. All samples of Y. longistaminea formed a clade. Yunnanopilia, Melientha, and Champereia were more closely related than other genera of Opiliaceae. Yunnanopilia longistaminea was sister to M. suavis Pierre and was more closely related to M. suavis than to C. manillana. Morphological analysis also showed that differences in the inflorescences and flowers between Y. longistaminea and M. suavis were substantial enough to warrant the retention of Y. longistaminea in its current genus. Thus, we suggest that the monotypic Yunnanopilia be treated as a distinct genus and that the name Y. longistaminea should be adopted.
• Phylogeny and a new tribal classification of Opiliaceae (Santalales) based on molecular and morphological evidence

  Chi-Toan Le, Bing Liu, Russell L. Barrett, Li-Min Lu, Jun Wen, Zhi-Duan Chen

  J Syst Evol. 2018, 56(1): 56-66.
  https://doi.org/10.1111/jse.12295

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  Opiliaceae are a pantropical family of the Santalales mainly distributed in the Old World with only one genus in the neotropics. Opiliaceae have remained taxonomically unresolved and the generic relationships within the family have been disputed. Here we present molecular phylogenetic analyses of the family and its close relatives using a combined dataset of the nuclear ribosomal (small subunit rDNA and large subunit rDNA) and the chloroplast rbcL, matK, and trnL-F regions. We also carried out a morphological phylogenetic analysis using 24 characters for all the species of Opiliaceae and three species in Santalaceae s.l. and Strombosiaceae as outgroups. Molecular analyses strongly supported the monophyly of Opiliaceae. Agonandra Miers ex Benth. & Hook. f. is sister to all the other genera of Opiliaceae. The remaining genera form two major clades: the Opilia clade (including Cansjera Juss., Lepionurus Blume, Opilia Roxb., Pentarhopalopilia (Engl.) Hiepko, Rhopalopilia Pierre, and Urobotrya Stapf.), and the other consisting of Anthobolus plus the Champereia clade (including Champereia Griff., Melientha Pierre, and Yunnanopilia C. Y. Wu & D. Z. Li). We propose a new classification of Opiliaceae, recognizing 12 genera and four tribes, with the description of a new tribe, Champereieae Bing Liu, C. T. Le, L. M. Lu & Z. D. Chen.
• Reinerantha foliicola, a new genus and species of Lejeuneaceae subtribe Cololejeuneinae (Marchantiophyta) from Ecuador

  S. Robbert Gradstein, Rui-Liang Zhu, Lei Shu, Álvaro J. Pérez

  J Syst Evol. 2018, 56(1): 67-75.
  https://doi.org/10.1111/jse.12293

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  Cololejeuneinae is the largest subtribe of the liverwort family Lejeuneaceae and the crown group of the family. The species often grow on the surfaces of living leaves and twigs or in swiftly running waters and many of them possess neotenic gametophytes, considered an adaptation to these extreme habitats. We describe a new, epiphyllous genus and species in Cololejeuneinae from the Western Cordillera of Ecuador, Reinerantha foliicola Gradst. & R.L.Zhu. Analysis of combined molecular datasets with parsimony, maximum likelihood and Bayesian methods revealed Reinerantha in a sister relationship to the large pantropical genus Diplasiolejeunea. Reinerantha differs from Diplasiolejeunea in leaf segmentation, epidermal wall thickening, stylus, male bracts and perianth keels, and is morphologically more similar to the genus Tuyamaella. In the molecular analysis, however, Reinerantha and Tuyamaella were resolved in different clades and not closely related. Tuyamaella is shown to be restricted to Asia; the report of Tuyamaella from South America (Peru) was erroneous and a case of mislabeling.
• List of Reviewers

  J Syst Evol. 2018, 56(1): 76-77.
  https://doi.org/10.1111/jse.12297

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  The Journal of Systematics and Evolution would like to acknowledge and thank the following reviewers for their contributions in the period January 1–December 31 in 2017:

  Abdel Khalik, Kadry N.

  Austen, Emily

  Bernhardt, Harold

  Birchler, James A.

  Bocksberger, Gaelle

  Bogunić, Faruk

  Bohs, Lynn

  Bush, Catherine M.

  Caicedo, Ana

  Caraballo, Marcos

  Chapman, Mark

  Charlesworth, Deborah

  Chen, Jin‐Ming

  Chen, Si‐Xue

  Chen, Zhi‐Duan

  Cheng, Zhou

  Christenhusz, Maarten J. M.

  Cires, Eduardo

  Corlett, Richard

  Crase, Beth

  Crayn, Darren

  Dai, Wei‐Min

  Davis, Jerrold

  Deng, Yun‐Fei

  Ding, Yu‐Long

  Duan, Yuan‐Wen

  Duckett, Jeffrey

  Ebach, Malte

  Ebihara, Atsushi

  Ekrt, Libor

  Endress, Peter

  Evans, Rodger

  Feng, Chunmiao

  Fernández Pepi, María Gabriela

  Ferreira, Fabricio Moreira

  Feuillet, Christian

  Gao, Lian‐Ming

  Ge, Xue‐Jun

  Gerrath, Jean

  Glennon, Kelsey

  Gong, Xun

  Gopakumar, B.

  Gottsberger, Gerhard

  Guo, Ya‐Long

  Guo, Zhen‐Hua

  Halkier, Barbara

  Harris, AJ

  Herendeen, Patrick

  Heyduk, Karolina

  Hileman, Lena

  Hoffmann, Matthias H.

  Hong, De‐Yuan

  Hou, Chen

  Hovenkamp, Peter

  Huang, Jin‐Ling

  Icker‐Bond, Stefanie

  Islam, Md‐Sajedul

  Jaramillo, Maria

  Jin, Xiao‐Hua

  Johnson, Leigh

  Kaczorowski, Rainee L.

  Keller, Barbara

  Kitadai, Norio

  Knapp, Sandra

  Kowlski, Rafal

  Kron, Paul

  Kuss, Patrick

  Labiak, Paulo

  Levin, Geoffrey

  Li, Jianhua

  Li, Lin‐Feng

  Liu, Jian‐Quan

  Liu, Liang‐Chun

  Liu, Ping‐Li

  Lu, Bao‐Rong

  Lu, Jin‐Mei

  Lu, Li‐Min

  Maia, Artur

  Manchester, Steven

  Mandel, Jennifer

  McDaniel, Stuart

  Medrano, Monica

  Metzgar, Jordan

  Middleton, David

  Murray, David

  Nie, Ze‐Long

  Nikolov, Lachezar

  Olsen, Kenneth M.

  Park, Chong‐Wook

  Parnell, John

  Pei, Nancai

  Peng, Hua

  Pfeiffer, Ilona

  Pigg, Kathleen

  Pirie, Michael

  Pócs, Tamás

  Preston, Jill

  Qi, Xinshuai

  Qiao, Ge‐Xia

  Qiu, Ying‐Xiong

  Raes, Niels

  Rebman, Jon

  Ren, Yi

  Rindi, Fabio

  Roy, Tilottama

  Rutishauser, Rolf

  Schaefer‐Verwimp, Alfons

  Scherson, Rosa

  Simpson, Beryl

  Soltis, Douglas

  Sosa, Victoria

  Soto Gomez, Marybel

  Stevens, Peter

  Stuessy, Tod

  Su, Tao

  Suarez‐Santiago, Victor N.

  Sukhorukov, Alexander P.

  Sun, Gen‐Lou

  Svoboda, Harlan

  Swanson, David

  Tarkhnishvili, David

  Tiffney, Bruce

  Trias Blasi, Anna

  Vallès, Joan

  van Welzen, Peter

  Vanderpoorten, Alain

  Vargas, Oscar

  Vorontsova, Maria S.

  Wachowiak, Witold

  Wang, Heng‐Chang

  Wang, Hong

  Wang, Yin‐Zheng

  Wang, Yu‐Guo

  Wen, Jun

  Wheeler, Elisabeth

  Williams, David

  Wu, Zhi‐Qiang

  Xiang, Chun‐Lei

  Xing, Yao‐Wu

  Yang, Chun‐Feng

  Yang, Fu‐Sheng

  Yang, Wu‐Yun

  Yang, Zai‐Jun

  Yu, Dong‐Liang

  Yu, Yan

  Zhang, Li‐Bing

  Zhang, Ming‐Li

  Zhang, Ning

  Zhang, Xian‐Chun

  Zhao, Yun‐Peng

  Zhou, Ren‐Chao

  Zhou, Shi‐Liang

  Zhou, Yong‐Feng

  Zhou, Zhan

• Corrigendum

  J Syst Evol. 2018, 56(1): 78-78.
  https://doi.org/10.1111/jse.12296

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