Table of Contents
  • Volume 53 Issue 2

    Cover illustration: New phylotaxonomy of grasses, includes 12 subfamilies (Anomochlooideae, Pharoideae, and Puelioideae forming the basal lineages; Oryzoideae, Bambusoideae, and Pooideae forming the BOP clade; and Aristidoideae, Panicoideae, Arundinoideae, Micraioideae, Danthonioideae, and Chloridoideae forming the PACMAD clade), 51 tribes, and 80 subtribes evolving clockwise. Triangles are proportional in height to the size of the taxon. See Soreng et al., pp. 117–137 in this issue.
      
      Invited Review
    • Robert J. Soreng, Paul M. Peterson, Konstantin Romaschenko, Gerrit Davidse, Fernando O. Zuloaga, Emmet J. Judziewicz, Tarciso S. Filgueiras, Jerrold I. Davis, and Osvaldo Morrone
      2015, 53 (2): 117–137
      Abstract   |   References   |   Full Text HTML   |   Full Text PDF   |   Save
      Based on recent molecular and morphological studies we present a modern worldwide phylogenetic classification of the ± 12074 grasses and place the 771 grass genera into 12 subfamilies (Anomochlooideae, Aristidoideae, Arundinoideae, Bambusoideae, Chloridoideae, Danthonioideae, Micraioideae, Oryzoideae, Panicoideae, Pharoideae, Puelioideae, and Pooideae), 6 supertribes (Andropogonodae, Arundinarodae, Bambusodae, Panicodae, Poodae, Triticodae), 51 tribes (Ampelodesmeae, Andropogoneae, Anomochloeae, Aristideae, Arundinarieae, Arundineae, Arundinelleae, Atractocarpeae, Bambuseae, Brachyelytreae, Brachypodieae, Bromeae, Brylkinieae, Centotheceae, Centropodieae, Chasmanthieae, Cynodonteae, Cyperochloeae, Danthonieae, Diarrheneae, Ehrharteae, Eragrostideae, Eriachneae, Guaduellieae, Gynerieae, Hubbardieae, Isachneae, Littledaleeae, Lygeeae, Meliceae, Micraireae, Molinieae, Nardeae, Olyreae, Oryzeae, Paniceae, Paspaleae, Phaenospermateae, Phareae, Phyllorachideae, Poeae, Steyermarkochloeae, Stipeae, Streptochaeteae, Streptogyneae, Thysanolaeneae, Triraphideae, Tristachyideae, Triticeae, Zeugiteae, and Zoysieae), and 80 subtribes (Aeluropodinae, Agrostidinae, Airinae, Ammochloinae, Andropogoninae, Anthephorinae, Anthistiriinae, Anthoxanthinae, Arthraxoninae, Arthropogoninae, Arthrostylidiinae, Arundinariinae, Aveninae, Bambusinae, Boivinellinae, Boutelouinae, Brizinae, Buergersiochloinae, Calothecinae, Cenchrinae, Chionachninae, Chusqueinae, Coicinae, Coleanthinae, Cotteinae, Cteniinae, Cynosurinae, Dactylidinae, Dichantheliinae, Dimeriinae, Duthieinae, Eleusininae, Eragrostidinae, Farragininae, Germainiinae, Gouiniinae, Guaduinae, Gymnopogoninae, Hickeliinae, Hilariinae, Holcinae, Hordeinae, Ischaeminae, Loliinae, Melinidinae, Melocanninae, Miliinae, Monanthochloinae, Muhlenbergiinae, Neurachninae, Olyrinae, Orcuttiinae, Oryzinae, Otachyriinae, Panicinae, Pappophorinae, Parapholiinae, Parianinae, Paspalinae, Perotidinae, Phalaridinae, Poinae, Racemobambosinae, Rottboelliinae, Saccharinae, Scleropogoninae, Scolochloinae, Sesleriinae, Sorghinae, Sporobolinae, Torreyochloinae, Traginae, Trichoneurinae, Triodiinae, Tripogoninae, Tripsacinae, Triticinae, Unioliinae, Zizaniinae, and Zoysiinae). In addition, we include a radial tree illustrating the hierarchical relationships among the subtribes, tribes, and subfamilies. We use the subfamilial name, Oryzoideae, over Ehrhartoideae because the latter was initially published as a misplaced rank, and we circumscribe Molinieae to include 13 Arundinoideae genera. The subtribe Calothecinae is newly described and the tribe Littledaleeae is new at that rank.
    • Research Article
    • Robert J. Soreng, Lynn J. Gillespie, Hidehisa Koba, Ekaterina Boudko, and Roger D. Bull
      2015, 53 (2): 138–162
      Phylogenetic analyses within Poaceae tribe Poeae subtribes Puccinellinae (=Coleanthinae), Phleinae, Poinae s.l. (including Alopecurinae), and Miliinae (PPAM clade), revealed that one species formerly placed in Poa represents a new monotypic genus belonging to subtribe Poinae s.l., Dupontiopsis gen. nov., D. hayachinensis comb. nov. (based on Poa hayachinensis), endemic to wet, gravelly, serpentine, alpine habitats in northern Japan. This genus forms a strongly supported clade (DAD) with two circumarctic Poinae genera, Arctophila and Dupontia, in phylogenetic analyses of plastid and nuclear ribosomal DNA sequence data. Both morphology and DNA sequence analyses provide support for D. hayachinensis as a lineage distinct from either Arctophila or Dupontia, with moderate DNA support for a position as sister to these two genera. Dupontiopsis resembles these other monotypic genera in its several-flowered spikelets, lemmas usually 3-nerved, with frequently awned attenuate scarious apices (as in Dupontia) and calluses with a crown of hairs around the base of the lemma, but differs in its keeled lemmas, scabrous palea keels, glumes shorter than the first lemma. Our investigation suggests that the most recent shared ancestor of the DAD clade evolved from a single hybridization event, as a hexaploid, probably in western Beringia. The probable parentage of the ancestor is considered to be within the Poinae–Alopecurinae clade excluding Poa. We provide evidence for possible secondary hybridization and introgression of duodecaploid Dupontia fisheri with Puccinellia. A key to perennial genera of PPAM with hairy calluses, and a supplemental table of morphological characters in the genera accepted in PPAM are provided.
    • Letter to the Editor
    • Wei‐Ning Bai and Da‐Yong Zhang
      2015, 53 (2): 163–165
      Abstract   |   References   |   Full Text HTML   |   Full Text PDF   |   Save
    • Research Articles
    • Xiao-Qin Wu, Pei-Xing Li, Xiao-Fang Deng, and Dian-Xiang Zhang
      2015, 53 (2): 166–178
      Abstract   |   References   |   Full Text HTML   |   Full Text PDF   |   Save
      Typical distylous species display both reciprocal herkogamy and heteromorphic incompatibility, which exclude self- and intramorph pollination and accordingly promote intermorph pollination. Here we explore an unusual distylous flower associated with self- and intramorph compatibility in Mussaenda macrophylla Wall. The species did not exhibit a precise reciprocal herkogamy, and the populations studied had a slight bias in favor of the short-styled morph (S-morph). In addition, pollen tube growth in intermorph pollination was faster than either in intramorph or self-pollination, indicating that cryptic heteromorphic self-incompatibility occurred in M. macrophylla. Specifically, pollen tube growth rates after legitimate and illegitimate pollination were much more highly differentiated in long-styled morph (L-morph) than in S-morph, which might be attributed to the increased de-esterified pectin in the tip of L-morph pollen tube wall in comparison with S-morph. Transmission electron microscopic observation revealed illegitimate self-pollinated pollen tubes of two morphs were seriously degraded with the large autolysosome-like vacuoles in cytoplasm of L-morph pollen tube but accumulating small vacuoles in that of S-morph pollen tube, suggesting that incompatible pollen tubes might undergo autophagic programmed cell death except self-incompatible S-morph pollen tubes. Our results indicate that M. macrophylla is morphologically distylous with a cryptic heteromorphic self-incompatibility breeding system, which functions differently in S-morph with self-pollination compared with other illegitimate pollination.
    • Xiao-Qin Li, Qin Zuo, Min Li, Si He, Yu Jia, and You-Fang Wang
      2015, 53 (2): 179–190
      Abstract   |   References   |   Full Text HTML   |   Full Text PDF   |   Save
      The current circumscription of the eight closely related morphospecies with propagula in Pseudotaxiphyllum Z. Iwats. is extremely unsatisfactory because of the ill-defined delimitation of the species concepts. In order to determine the systematic positions of these closely related species, a phylogenetic reconstruction was carried out based on molecular analyses of two genomic compartments (chloroplast ndhB, rpl16, trnG, trnL-F, and nuclear ribosomal internal transcribed spacer (nrITS)) together with a haplotype network analysis and species delimitation assessments by thorough morphological studies. The results of the present study show that P. elegans (Brid.) Z. Iwats. was closely related to P. laetevirens (Dixon & Luisier ex F. Koppe & Düll) Hedenäs and both species together with P. maebarae(Sakurai) Z. Iwats. were resolved as monophyletic clades. Pseudotaxiphyllum arquifolium (Bosch & Sande Lac.) Z. Iwats., P. densum (Cardot) Z. Iwats., P. fauriei(Cardot) Z. Iwats., the Asian populations of P. distichaceum (Mitt.) Z. Iwats. and P. pohliaecarpum (Sull. & Lesq.) Z. Iwats. are morphologically identical. At least three cryptic lineages with undifferentiated morphological or geographical pattern were inferred from this species complex. We propose that the above-mentioned morphospecies be synonymized under P. distichaceum, and the American ‘P. distichaceum’ be replaced by a new name, P. subfalcatum (Austin) X. Q. Li, Q. Zuo & Y. F. Wang, stat. nov. Pseudotaxiphyllum obtusifolium Z. Iwats. & B. C. Tan was treated as P. distichaceum (Mitt.) Z. Iwats. var. obtusifolium (Z. Iwats. & B. C. Tan) X. Q. Li, Q. Zuo & Y. F. Wang, stat. nov.
    • Xin‐Bo Zhang, Xiang‐Ming Ma, Bai‐Yun Wang, Xiang‐Hui Ma, and Zhi‐Wen Wang
      2015, 53 (2): 191–195
      The evolutionary suppression of synonymous codon sites is a controversial topic. Although some studies have indicated that synonymous substitution is under positive selection, most of these studies relied on comparison of homologous genes and/or a limited number of sequences. In the present work, we compared the selection strength at synonymous sites for two types of protein-encoding genes: genes encoding enzymes and protein genes encoding non-enzymes. Our method does not require assumptions concerning, for example, evolutionary equilibrium or population size. We compared ∼70 000 genes from the fully sequenced mammalian Homo sapiens, Pan troglodytes, Mus musculus, and Rattus norvegicus genomes and found that the percentage of C and G in the third position of a codon positively correlates with the percentage of the G/C content within ± 20 000 nucleotides of the gene. More interestingly, we found that synonymous sites in mammalian genes encoding enzymes have undergone stronger selection than did such sites in genes encoding proteins that are not enzymes.
    • Gao Chen, Wei-Chang Gong, Jia Ge, Yang Niu, Xin Zhang, Bruce L. Dunn, and Wei-Bang Sun
      2015, 53 (2): 196–202
      In this study, floral color, scent composition and emission rate, nectar property, pollinators, and breeding system of dimorphic Buddleja delavayi Gagnep. were investigated. Flower color of B. delavayi was determined using a standard color chart and spectrophotometer, and two distinct color polymorphisms were observed having purple or white flowers. Floral scents of B. delavayi were collected using dynamic headspace adsorption and identified with coupled gas chromatography and mass spectrometry. In total, 28 compounds were identified from the flowers of B. delavayi. The identified scents were divided into three chemical classes based on their biosynthetic origin: terpenes, fatty acid derivatives, and benzenoids. The scent profiles in all individuals were dominated by a few components, such as lilac aldehyde and alcohol, 4-oxoisophorone, benaldehyde, and oxoisophorone oxide. Floral scent composition (benzenoids and terpenes) showed a significant difference between white and purple flower morphs. Flower color–flower scent associations in B. delavayi were identified with two distinct scent profiles in the two color phenotypes. The studies of other floral characteristics (nectar, floral visitors, breeding system, and fruit set) indicated that floral scent emission rate, nectar volume, visitor visitation frequency, and natural fruit set were not significantly different between the two flower color morphs. Bagging experiments revealed that seed production of B. delavayi is dependent mainly on honeybee Apis cerana. Lastly, this study implies that dimorphic floral color in B. delavayi may have been maintained by floral visitors and nectar guide color.
Editors-in-Chief
Song Ge
Jun Wen
Impact Factor
2.779
JCR 2019 IF ranking: 56/234 (Plant Sciences, top 23.72%, Q1 quartile)
Journal Abbreviation: J Syst Evol
ISSN: 1674-4918 (Print)
1759-6831 (Online)
CN: 11-5779/Q
Frequency: Bi-monthly

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