Analysis of phylogenetic relationships of Brassicaceae species based on Chs sequences

Sequences of nuclear chalcone synthase gene (Chs) were analyzed for species of the Brassicaceae family to reconstruct phylogenetic relationships. The phylogeny for 106 species of 60 genera was reconstructed, and assigned to 24 tribes, using maximum parsimony, maximum likelihood, and neighbor-joining methods. Most of the tribes can be assigned to the major lineages (Lineages I–III) suggested by Beilstein et al. (2006). The tribe Camelineae was not monophyletic. Conringia planisiliqua together with Orychophragmus violaceus would not be recognized as a new tribe proposed by the previous studies, and C. planisiliqua should be a member of tribe Isatideae. The genera delimitation and monophyly of the expanded Solms-laubachia were also confirmed by our data. Furthermore, one parent of inter-tribal allopolyploid Pachycladon appeared to be most closely associated with Crucihimalaya, Transberingia and tribes Boechereae and Halimolobeae, another parent was proved to be in tribe Smelowskieae.     

Closing the gaps: phylogenetic relationships in the Brassicaceae based on DNA sequence data of nuclear ribosomal ITS region

Sequence data from the nuclear encoded ribosomal internal transcribed spacer (ITS) region were used to determine monophyly of tribes, tribal limits, and tribal relationships of 96 so far unassigned or tentatively assigned genera (represented by 101 taxa/accessions) within the Brassicaceae. Maximum-parsimony and maximum-likelihood analyses of 185 ITS Brassicaceae sequences, which also included representatives of each of the 34 currently recognized tribes, supported the separate phylogenetic distinctness of these tribes and permitted the tribal assignment of all but 12 of the unassigned genera into tribal clades. The data support the recognition of eight new, well-resolved, uni- or oligogeneric tribes recognized herein as the Alyssopsideae [96% bootstrap support (BS); including the central and southwestern Asian Alyssopsis and Calymmatium], Asteae (100% BS; including the Mexican Asta), Eudemeae (97% BS; South American Brayopsis, Eudema, and Xerodraba), Kernereae (96% BS; European Kernera and Rhizobotrya), Notothlaspideae (100% BS; New Zealandic Notothlaspi), Oreophytoneae (100% BS; eastern African Oreophyton and southern European Murbeckiella), and Yinshanieae (100% BS; Chinese Yinshania), as well as the moderately supported Microlepidieae (75% BS; Australian Microlepidium and Carinavalva). Furthermore, the results fully support the recent findings that the tribes Schizopetaleae and Thelypodieae ought to be recognized as two distinct tribes instead of a single tribe, as well as provide some support for the re-establishment of the tribe Cremolobeae, bringing the total number to 44 tribes in the family. Nearly 92% (308) of the 336 genera in the family have been assigned to a tribe. The earlier-published Anastaticeae is taken here to replace the Malcolmieae.     

Revision and tribal placement of the Argentinean genus Parodiodoxa (Brassicaceae)

Parodiodoxa is a monotypic genus of Brassicaceae endemic to northwestern Argentina. It is poorly known and until now remained the only South American genus of the family that had not been assigned to a particular tribe. Sequence data from the nuclear ribosomal ITS region and the chloroplast trnL intron/trnL-F spacer region were used in this study to determine the systematic position of Parodiodoxa. For this purpose, taxa were sampled both at the tribal and generic levels. Results from tribal-level sampling support the inclusion of Parodiodoxa in the tribe Thelypodieae, whereas those at the generic level reveal a relationship to Weberbauera (W. rosulans and W. herzogii). Topologies within the Thelypodieae were poorly resolved, in agreement with previous studies. Morphological characteristics of Parodiodoxa are also discussed in relation to other genera of the tribe.     

The Chloroplast Genome of Hyoscyamus niger and a Phylogenetic Study of the Tribe Hyoscyameae (Solanaceae)

The tribe Hyoscyameae (Solanaceae) is restricted to Eurasia and includes the genera Archihyoscyamus, Anisodus, Atropa, Atropanthe, Hyoscyamus, Physochlaina, Przewalskia and Scopolia. Even though the monophyly of Hyoscyameae is strongly supported, the relationships of the taxa within the tribe remain unclear. Chloroplast markers have been widely used to elucidate plant relationships at low taxonomic levels. Identification of variable chloroplast intergenic regions has been developed based on comparative genomics of chloroplast genomes, but these regions have a narrow phylogenetic utility. In this study, we present the chloroplast genome sequence of Hyoscyamus niger and make comparisons to other solanaceous plastid genomes in terms of gene order, gene and intron content, editing sites, origins of replication, repeats, and hypothetical open reading frames. We developed and sequenced three variable plastid markers from eight species to elucidate relationships within the tribe Hyoscyameae. The presence of a horizontally transferred intron in the mitochondrial cox1 gene of some species of the tribe is considered here a likely synapomorphy uniting five genera of the Hyoscyameae. Alternatively, the cox1 intron could be a homoplasious character acquired twice within the tribe. A homoplasious inversion in the intergenic plastid spacer trnC-psbM was recognized as a source of bias and removed from the data set used in the phylogenetic analyses. Almost 12 kb of plastid sequence data were not sufficient to completely resolve relationships among genera of Hyoscyameae but some clades were identified. Two alternative hypotheses of the evolution of the genera within the tribe are proposed.     

First phylogenetic analysis of the tribe Oligaphorurini (Collembola: Onychiuridae) inferred from morphological data,with implications for generic classification

Oligaphorurini represent tribe of the subfamily Onychiurinae, which currently comprises 5 genera and 53 species. The present study evaluated the monophyly of Oligaphorurini genera. We investigated phylogenetic relationships among 39 species, representing all extant genera of Oligaphorurini. Both equal- and implied-weighting parsimony analyses were used in phylogenetic reconstruction. The cladistic analyses were based on comprehensive survey of adults’ morphological characters because specimens suitable for molecular studies were not available for the majority taxa. The phylogenetic analysis resulted in the recognition of a monophyletic Chribellphorura, and strongly supported non-monophyly of the previously recognized genera Archaphorura, Dimorphaphorura, Micraphorura, and Oligaphorura. The following new synonymy is recognized: Oligaphorura = Dimorphaphorura syn. nov., = Micraphorura syn. nov., = Archaphorura syn. nov. The general classification of Oligaphorurini is followed by the diagnoses of genera and key to the all known species.     

Phylogenetic relationships of Old World Brassicaceae from Iran based on nuclear ribosomal DNA sequences

Phylogenetic analysis of 155 nuclear rDNA ITS sequences among them 19 Iranian endemic genera were used to elucidate phylogenetic relationships of Old World Brassicaceae from Iran in the context of the most recent tribal system suggested by Al-Shehbaz et al. [Al-Shehbaz, I.A., Beilstein, M.A, Kellogg, E.A., 2006. Systematics and phylogeny of the Brassicaceae (Cruciferae): an overview. Plant Syst. Evol. 259, 89–120]. Iranian endemic taxa are assigned to 16 clades, 15 of these correspond to recognized tribes. Our data support the recent tribal recognition of Calepina and relatives and further indicate that the Orychophragmus clade (with Conringia planisiliqua and Orychophragmus) may be recognized as a new tribe. Our data also support the inclusion of 13 genera not previously studied, or with unresolved positions in previous phylogenetic analyses in 10 tribes with the tribal assignment given in parentheses: Acanthocardamum (Aethionemeae), Alyssopsis (Camelineae), Anastatica (Malcolmieae), Asperuginoides (Cochlearieae), Camelinopsis (Thlaspideae), Didymophysa (Thlaspideae), Dielsiocharisi (Camelineae), Lachnoloma (Anchonieae), Micrantha (Anchonieae), Noccidium (Camelineae), Octoceras (Euclidieae), Pseudofortuynia (Sisymbrieae) and Streptoloma (Euclidieae). ITS data and morphological characters further indicate that the remaining five genera, i.e., Acanthocardamum, Olimarabidopsis, Brossardia, Noccidium and Zuvanda may be subsumed under Aethionema, Alyssopsis, Noccaea, Capsella and Conringia, respectively. Alyssum, Chorispora, Fibigia and Goldbachia are paraphyletic and Conringia, Malcolmia, Matthiola are polyphyletic taxa.     

Phylogenetic relationships,subdivision, and biogeography of the cyprinid tribe Labeonini (sensu ) (Teleostei: Cypriniformes), with comments on the implications of lips and associated structures in the labeonin classification

The Labeonini (sensu Rainboth, 1991) is a tribe of the subfamily Cyprininae, the largest subfamily of Cypriniformes. With around 400 species in 34 genera, this tribe is widely distributed in the freshwaters of tropical Africa and Asia. Most species are adapted to fast-flowing streams and rivers, and exhibit unique morphological modifications associated with their lips and other structures around the mouth. The monophyly of this tribe has been tested and generally accepted in previous morphological and molecular studies. The major objectives of this study were to reconstruct the phylogenetic relationships within the tribe Labeonini, test its monophyly and explore the taxonomic subdivisions, intrarelationships and biogeography of the group. The value of the morphological characters associated with the lips and other associated structures in the taxonomic classification of labeonins was also discussed. Nucleotide sequences (3867 bp) of four unlinked nuclear loci were obtained from 51 species in 18 Labeonini genera from throughout the range of the tribe. Maximum parsimony, partitioned maximum likelihood and partitioned Bayesian analyses were used for phylogenetic inference from combined and separate gene data sets. Based on our results, the monophyly of Labeonini was well supported. Two major clades could be recovered within the tribe. Three subclades could further be recognized from the first clade. These clades/subclades are not consistent with groupings of any of previous workers using either morphological or molecular characters for phylogenetic inference. Only five currently recognized genera in this analysis are monophyletic. The similarity between some lips and associated structures (e.g. suctorial discs) of labeonins may due to convergence or parallelism instead of common ancestry. Labeonins of Southeast Asia, India and China are closely related to each other; the multiple clades of African taxa do not form a single monophyletic group, indicating multiple, independent dispersal events of labeonins into Africa from Asia.     

Phylogeny and classification of diving beetles in the tribe Cybistrini (Coleoptera, Dytiscidae, Dytiscinae)

Phylogenetic relationships among members of the diving beetle tribe Cybistrini (Coleoptera: Dytiscidae) were inferred from analysis of 47 adult and larval morphological characters and sequences from portions of the genes cytochrome oxidase I (COI) and II (COII), histone III (H3) and wingless. Thirty‐three species of Cybistrini were included, representing all genus‐groups except Regimbartina Chatanay and Megadytes (Bifurcitus) Brinck, and most historically recognized species groups and subgenera used in the tribe. Outgroups include six species from other tribes within Dytiscinae and Lancetinae. Analyses included parsimony analysis of the combined data, likelihood analysis of combined molecular data and partitioned Bayesian analysis of the combined data. Results indicate that Cybistrini is well supported as a monophyletic group. Within the tribe, all currently recognized genus groups were found to be monophyletic with the exception of Onychohydrus Schaum, which is paraphyletic with respect to Austrodytes Watts in the parsimony analysis, but monophyletic in the likelihood and Bayesian analyses, and Cybister sensu stricto, which is paraphyletic with respect to C. (Melanectes) Brinck and C. (Scaphinectes) Ádám in the parsimony analysis or only the latter in the likelihood and Bayesian analyses. Results also suggest that some, but not all, historically recognized species groups or subgenera in the large genus Cybister Curtis are monophyletic, and this is discussed and compared. To improve the classification, the name Sternhydrus Brinck is elevated from subgenus to genus rank ( new status ). Four subgenera in the genus Cybister are recognized: C. (Melanectes) Brinck, C. (Megadytoides) Brinck ( resurrected ), C. (Neocybister) Miller, Bergsten and Whiting ( new subgenus ) and C. (Cybister) Curtis. The following new synonyms are established: Trochalus Dejean ( new synonym ), and ScaphinectesÁdám = Cybister (Cybister) ( new synonym ). The Neotropical species Cybister parvus Trémouilles (not examined) apparently does not fit any historical or currently recognized genus‐group diagnosis in Cybistrini, so it is retained in Cybister but incertae sedis with respect to subgenus. In addition to classification, the evolution of the unique character combinations present in cybistrines are discussed. A key to the adults of genera and subgenera is presented.     

Comparison of methods for rooting phylogenetic trees: A case study using Orcuttieae (Poaceae: Chloridoideae)

DNA sequence data (cpDNA trnL intron and nrDNA ITS1 and ITS2) were analyzed to identify relationships within Orcuttieae, a small tribe of endangered grasses endemic to vernal pools in California and Baja California. The tribe includes three genera: Orcuttia, Tuctoria, and Neostapfia. All three genera carry out C₄ photosynthesis but aquatic taxa of Orcuttia lack Kranz anatomy. The unusual habitat preference of the tribe is coupled with the atypical development of C₄ photosynthesis without Kranz anatomy. Furthermore, the tribe has no known close relatives and has been noted to be phylogenetically isolated within the subfamily Chloridoideae. In this study we examine the problem of inferring the root of the tribe in the absence of an identified outgroup, analyze the phylogenetic relationships of the constituent taxa, and evaluate the evolutionary development of C₄ photosynthesis. We compare four methods for inferring the root of the tree: (1) the outgroup method, (2) midpoint rooting, the imposition of a molecular clock for both (3) maximum likelihood (ML) and (4) Bayesian analysis. We examine the consequences of each method for the inferred phylogenetic relationships. Three of the methods (outgroup rooting and the ML and Bayesian molecular clock analyses) suggest that the root of Orcuttieae is between Neostapfia and the Tuctoria/Orcuttia lineage, while midpoint rooting gives a different root. The Bayesian method additionally provides information about probabilities associated with other possible root locations. Assuming that the true root of Orcuttieae is between Neostapfia and the Tuctoria/Orcuttia lineage, our data indicate Neostapfia and Orcuttia are both monophyletic, while Tuctoria is paraphyletic (with no synapomorphies in either dataset) and forming a grade between the other two genera and needs taxonomic revision. Our data support the hypothesis that Orcuttieae was derived from a terrestrial ancestor and evolved specializations to an aquatic environment, including C₄ photosynthesis without Kranz anatomy.     

Comparative detailed morphology of the Heteroderinae Filip'ev & Schuurmans Stekhoven, 1941, sensu Luc et al. (1988): phylogenetic systematics and revised classification

Taxonomic schemes for the Heteroderinae Filip'ev & Schuurmans Stekhoven, 1941, sensu Luc et al., (1988) have been unstable due to the large number of genera and the paucity of known reliable characters. Reliable characters are essential when using phylogenetic inference in developing a natural classification. Morphological and developmental studies using light, scanning and transmission electron microscopy have revealed the new characters of host response, en face patterns, phasmid structure and female cuticular layers. These techniques also gave us insight into the homoplasy and polarity of many characters, revealed previously undetected character states and clarified misinterpreted character states. A matrix with the 19 most reliable characters is proposed for 20 operational taxonomic units (OTUs) and we employ this matrix for comparing computer generated phylogenetic analyses of the PHYLIP and PAUP packages. PAUP was deemed the more reliable parsimony algorithm for phylogenetic analysis of the Heteroderinae (Fink, 1986; Platnick, 1987). Monophyly of Atalodera + Sherodera + Thecavermiculatus (tribe Ataloderini), and Cactodera + Heterodera + Afenestrata, as well as Punctodera + Globodera + Dolichodera is supported by both programs. Most importantly, analyses strongly support monophyly of all cyst-forming genera (tribe Heteroderini) contrary to previous hypotheses of repeated evolution of the cyst (Wouts, 1985). In addition, monophyly of the Heteroderini with the Ataloderini is demonstrated. PAUP indicates monophyly of Sarisodera + Rhizonema + Bellodera + Hylonema and Ekphymatodera (tribe Sarisoderini new rank). Monophyly of the Sarisoderini was at first only weakly supported, but, subsequently, the reduced width of the submedial lips of second stage juveniles and males was recognized as a synapomorphy which strengthened subsequent PAUP trees and monophyly of the tribe. The present study rejects as paraphyletic or polyphyletic several previously proposed combinations, including Thecavermiculatus sequoiae (versus Rhizonema sequoiae), Sarisodera africana (versus Afenestrata africana), Dolichodera andinus (versus Thecavermiculatus andinus). The question whether T. andinus is a distinct genus, was not resolved due to insufficient data. PAUP supports our previous observations that Cactodera betulae is intermediate in a transformation series between other Cactodera and Heterodera: it also indicates these species as bring monophyletic with Heterodera + Afenestrata, but not with other Cactodera. Although these phylogenetic analyses strongly support some relationships, they indicate unresolved alternative hypotheses for others. Meloidodera (tribe Meloidoderini) and Cryphodera (tribe Cryphoderini) must be investigated for consideration of a possible synapomorphy not included in the present data matrix. Future studies are proposed to more clearly define the monophyly of the Heteroderini, as well as the Sarisoderini. Tests are also proposed to clarify questions of the monophyly of Verutus (tribe Verutini new rank) with the Heteroderinae versus other Tylenchida.     

A phylogeny of softshell turtles (Testudines: Trionychidae) with reference to the taxonomic status of the critically endangered,giant softshell turtle,Rafetus swinhoei

Several important aspects of the evolution of the softshell turtle (family Trionychidae) have not been addressed thoroughly in previous studies, including the pattern and timing of diversification of major clades and species boundaries of the critically endangered Shanghai Softshell Turtle, Rafetus swinhoei. To address these issues, we analyzed data from two mitochondrial loci (cytochrome b and ND4) and one nuclear intron (R35) for all species of trionychid turtles, except Pelochelys signifera, and for all known populations of Rafetus swinhoei in Vietnam and one from China. Phylogenetic analyses using three methods (maximum parsimony, maximum likelihood, and Bayesian inference) produce a well resolved and strongly supported phylogeny. The results of our time-calibration and biogeographic optimization analyses show that trionychid dispersals out of Asia took place between 45 and 49 million years ago in the Eocene. Interestingly, the accelerated rates of diversification and dispersal within the family correspond surprisingly well to global warming periods between the mid Paleocene and the early Oligocene and from the end of the Oligocene to the mid Miocene. Our study also indicates that there is no significant genetic divergence among monophyletic populations of Rafetus swinhoei, and that previous taxonomic revision of this species is unwarranted.     

A molecular and morphological phylogeny of the extant Augochlorini (Hymenoptera,Apoidea) with comments on implications for biogeography

The Augochlorini Beebe is a New World tribe of bees comprising 663 described species. Relationships among the genera of this monophyletic tribe remain uncertain. Here I provide a comprehensive phylogeny using morphological and molecular information. In all, 54 Augochlorini species plus 16 outgroups and 3017 molecular and 105 morphological characters were analysed. Sequences for four genes were analysed using Bayesian inference, maximum likelihood and parsimony. Morphological characters were taken from a literature review and analysed alone and in combination with molecular data using parsimony. The monophyly of Augochlorini and most genera is confirmed, with divergence of the main lineages of the tribe around 55–20 Ma. Seven clades were supported by most analyses and are here treated as genus‐level groups, as follows (combined analysis topology): (Corynura group, (Chlerogella group, (Rhinocorynura group, (Augochloropsis, (Megaloptidia group, (Neocorynura group, (Augochlora group, Megalopta group))))))). According to this topology, dim‐light foraging and cleptoparasitism arose three times in the tribe. According to my hypothesis, the diversification of Augochlorini may have begun as a response to vicariant events, including the split of the Neotropical/Andean regions and marine transgressions in the Amazon region.     

Phylogenetic analysis of cpDNA restriction sites andrps16 intron sequences reveals relationships among Apiaceae tribes Caucalideae, Scandiceae and related taxa

Evolutionary relationships among members of Apiaceae (Umbelliferae) tribe Caucalideae Spreng. and related taxa were inferred from maximum parsimony analyses of chloroplast DNA restriction sites andrps16 intron sequences and the results compared to an existing phylogeny for the group based on nuclear ribosomal DNA internal transcribed spacer sequences. While these three data sets were not similar in size or composition, the relationships among the shared taxa, with few exceptions, were concordant. Three major lineages are recognized, coinciding with the previously delimited Scandiceae subtribes Daucinae Dumort. (Agrocharis, Ammodaucus, Cuminum, Daucus, Orlaya, Pachyctenium, Pseudorlaya), Torilidinae Dumort. (Astrodaucus, Caucalis, Glochidotheca, Lisaea, Szovitsia, Torilis, Turgenia, Yabea), and Scandicinae Tausch (Anthriscus, Kozlovia, Myrrhis, Osmorhiza, Scandix). Included in Daucinae is representation from tribe Laserpitieae (Laser, Laserpitium, Melanoselinum, Monizia, Polylophium). Daucinae and Torilidinae arise as sister taxa in the chloroplast DNA-based phylogenies, whereas in the ITS trees relationships among the three major lineages are unresolved. Unexpectedly, three species ofFerula ally with Daucinae and Torilidinae. The position ofArtedia is equivocal, occurring either sister to Daucinae in the ITS trees, within Torilidinae in the intron trees, or sister to Torilidinae upon analysis of combined ITS and intron data.Chaetosciadium trichospermum emerges withinTorilis, and is recognized asTorilis trichosperma (L.) Spreng.     

Phylogenetic signatures of adaptation: The Arabis hirsuta species aggregate (Brassicaceae) revisited

The mustard family, Brassicaceae, is well-known for its homoplasy in almost any morphological character at practically all taxonomic levels. The genus Arabis, within the largest tribe of the Brassicaceae, is such an example comprising numerous para- and polyphyletic groups of taxa. Past research during the last 15 years has unraveled many phylogenetic relationships among the ∼550 (or more) species within the notoriously difficult tribe Arabideae. The European Arabis hirsuta species aggregate has remained unexplored, however. Herein we analyze phylogenetic relationships using nuclear ITS and plastid DNA sequences of Eurasian Arabis to characterize Hairy rock cress (A. hirsuta) and its relatives. Representative geographic sampling is used to study character and trait evolution, and bioclimatic data are used to differentiate between species. Our overview puts European Arabis into a reliable evolutionary framework, and we provide some striking insights into evolutionary trends and correlating morphological characters from seeds and flowers with environmental data such as climate variables and elevation. We demonstrate independent parallel evolution of sets of traits, and, therefore, we could further elaborate our previous findings that within tribe Arabideae high speciation rates are correlated with perennial growth form and occurrence at higher elevation. Finally some taxonomical remarks are provided to give added context.     

Using a phylogenetic approach to selection of target plants in drug discovery of acetylcholinesterase inhibiting alkaloids in Amaryllidaceae tribe Galantheae

We present phylogenetic analyses of 32 taxa of Amaryllidaceae tribe Galantheae, 6 taxa of other Eurasian genera of Amaryllidaceae and Phaedranassa dubia as outgroup in order to provide a phylogenetic framework for selection of candidate plants for lead discovery in relation to Alzheimer’s disease. We used DNA sequences from the nuclear ribosomal internal transcribed spacer (ITS) and the plastid matK and trnL-F regions. Phylogenetic analyses using maximum parsimony and Bayesian inference strongly support a monophyletic tribe Galantheae in a narrow sense, including only Acis, Galanthus and Leucojum. Infrageneric relationships of Galanthus only partly support previous classifications. Alkaloid profiles and inhibition of acetylcholinesterase (AChE) were investigated for 18 taxa using gas chromatography–mass spectrometry (GC–MS) and an assay measuring inhibition of AChE activity. AChE inhibitory activity was found in all investigated clades and was correlated with alkaloid profiles of the plants. Lowest IC₅₀ values were expressed by extracts containing either galanthamine or lycorine type compounds. Evaluation of available chemistry and activity data in a phylogenetic framework could be used to select target species for further investigation.     

Phylogenetic relationships in tribe Spiraeeae (Rosaceae) inferred from nucleotide sequence data

Tribe Spiraeeae has generally been defined to include Aruncus, Kelseya, Luetkea, Pentactina, Petrophyton, Sibiraea, and Spiraea. Recent phylogenetic analyses have supported inclusion of Holodiscus in this group. Spiraea, with 50-80 species distributed throughout the north temperate regions of the world, is by far the largest and most widespread genus in the tribe; the remaining genera have one to several species each. Phylogenetic analyses of nuclear ITS and chloroplast trnL-trnF nucleotide sequences for 33 species representing seven of the aforementioned genera plus Xerospiraea divided the tribe into two well supported clades, one including Aruncus, Luetkea, Holodiscus, and Xerospiraea, the second including the other genera. Within Spiraea, none of the three sections recognized by Rehder based on inflorescence morphology is supported as monophyletic. Our analyses suggest a western North American origin for the tribe, with several biogeographic events involving vicariance or dispersal between the Old and New Worlds having occurred within this group.     

中国大蒜芥族植物花粉形态的研究

对中国大蒜芥族10属14种植物花粉形态分别进行了光镜和扫描电镜下的观察研究。结果表明该族花粉形态可划分为4种类型：（1）具3沟,超长球形,网状纹饰,外壁2层;（2）具3沟,超长球形,细网状纹饰,外壁1层;（3）具3沟（偶4沟）,长球形,网状纹饰,外壁2层;（4）具6沟,长球形,网状纹饰,外壁2层。因此,中国大蒜芥族的花粉形态多样性程度较高,说明了它不是一个自然类群,是一个多系类群,这与前人研究结果相一致。另外,本文首次报道十字花科锥果芥属植物具6沟花粉,具6沟花粉在十字花科中极为特殊,所以作者将锥果芥属提升为族级,另立新族,即锥果芥族（Tribe Berteroelleae F．Z．Li,G．Y．Tang ＆ Z．Y．Sun,trib．nov．）。