Pollen Morphology and Plant Taxonomy: Angiosperms

The Caryophyllales constitute a major lineage of flowering plants with approximately 12500 species in 39 families. A taxonomic backbone at the genus level is provided that reflects the current state of knowledge and accepts 749 genera for the order. A detailed review of the literature of the past two decades shows that enormous progress has been made in understanding overall phylogenetic relationships in Caryophyllales. The process of re-circumscribing families in order to be monophyletic appears to be largely complete and has led to the recognition of eight new families (Anacampserotaceae, Kewaceae, Limeaceae, Lophiocarpaceae, Macarthuriaceae, Microteaceae, Montiaceae and Talinaceae), while the phylogenetic evaluation of generic concepts is still well underway. As a result of this, the number of genera has increased by more than ten percent in comparison to the last complete treatments in the Families and genera of vascular plants” series. A checklist with all currently accepted genus names in Caryophyllales, as well as nomenclatural references, type names and synonymy is presented. Notes indicate how extensively the respective genera have been studied in a phylogenetic context. The most diverse families at the generic level are Cactaceae and Aizoaceae, but 28 families comprise only one to six genera. This synopsis represents a first step towards the aim of creating a global synthesis of the species diversity in the angiosperm order Caryophyllales integrating the work of numerous specialists around the world.

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A taxonomic backbone for the global synthesis of species diversity in the angiosperm order Caryophyllales

The Plant Book, A Portable Dictionary of the Higher Plants.

Taxonomy of Polygonoideae (Polygonaceae): A new tribal classification

Calligonum (Polygonaceae) is distributed from southern Europe through northern Africa to central Asia, and is typically found in arid, desert regions. Previous studies have revealed that standard DNA barcodes fail to discriminate Calligonum species. In this study, the complete plastid genomes (plastome) for 32 accessions of 21 Calligonum species is sequenced to not only generate the first complete plastome sequence for the genus Calligonum but to also 1) Assess the ability of the complete plastome sequence to discern species within the group, and 2) screen the plastome sequence for a cost-effective DNA barcode that can be used in future studies to resolve taxonomic relationships within the group. The whole plastomes of Calligonum species possess a typical quadripartite structure. The size of the Calligonum plastome is approximately 161 kilobase pairs (kbp), and encodes 113 genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Based on ML phylogenetic tree analyses, the complete plastome has higher species identification (78%) than combinations of standard DNA barcodes (rbcL + matK + nrITS, 56%). Five newly screened gene regions (ndhF, trnS-G, trnC-petN, ndhF-rpl32, rpl32-trnL) had high species resolution, where ndhF and trnS-G were able to distinguish the highest proportion of Calligonum species (56%). The entire plastid genome was the most effective barcode for the genus Calligonum, although other gene regions showed great potential as taxon-specific barcodes for species identification in Calligonum.

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Complete plastome sequencing resolves taxonomic relationships among species of Calligonum L. (Polygonaceae) in China.

This study represents phylogenetic analyses of two woody polygonaceous genera Calligonum and Pteropyrum using both chloroplast fragment (trnL-F) and the nuclear ribosomal internal transcribed spacer (nrDNA ITS) sequence data. All inferred phylogenies using parsimony and Bayesian methods showed that Calligonum and Pteropyrum are both monophyletic and closely related taxa. They have no affinity with Atraphaxis, instead allied with a clade in which the genus is nested. Infrageneric relationships in Calligonum, due to the paucity of informative

http://www.ijbiotech.com/article_7122_8bd56f575495dae5615f19f45213c9de.pdf

The phylogeny of Calligonum and Pteropyrum (Polygonaceae) based on nuclear ribosomal DNA ITS and chloroplast trnL-F sequences

The phylogenetic status of the genus Atraphaxis and its relationship with woody Polygonum species is examined based on nrDNA ITS and two chloroplast regions (matK and rpl32-trnL(UAG)). Morphological and palynological studies for the selected taxa are also performed. Our results revealed that several woody Polygonum species (namely P. spinosum, P.
 aridum, P.
 dumosum, P.
 salicornioides, P. khajeh-jamali and P. botuliforme) endemic to Iran formed a distinct clade, and are nested within Atraphaxis. Atraphaxis ovczinnikovii, (=P.
 ovczinnikovii), was the first diverging lineage as sister to an assemblage of these taxa and the bulk of Atraphaxis species. Three other woody Polygonum species (P. afghanicum, P. paronychioides and P. thymifolium) were nested within herbaceous Polygonum species. Ochrea and pollen characteristics corroborated the phylogenetic results as well. Based on molecular and morphological evidence, we transferred the aforementioned six Polygonum species into Atraphaxis. The newly delimited genus Atraphaxis is comprised of three lineages, corresponding to three new sections: Atraphaxis, Polygonoides and Ovczinnikovia. The different position of A. botuliformis (=P. botuliforme) in nrDNA ITS and combined chloroplast DNA analyses indicated that it had possibly experienced the hybrid or introgression for a long time. Taxonomic descriptions for Atraphaxis and its sections as well as the diagnostic key to sections and species occurring in Iran, are presented.

Molecular phylogeny of Atraphaxis and the woody Polygonum species (Polygonaceae): taxonomic implications based on molecular and morphological evidence

Atraphaxis radkanensis Tavakkoli, Kaz. Osaloo & Mozaff. (Polygonaceae) is described and illustrated as a new species from NE Iran. Atraphaxis radkanensis is very similar to A. seravschanica, and both of them are placed in the section Tragopyrum. Atraphaxis radkanensis is characterized by oblong-ovate leaves, a puberulent indumentum on both surfaces of the leaves and twigs, a mostly terminal inflorescence, as well as by small-sized achenes.

Atraphaxis radkanensis (Polygonaceae), a New Species from Iran

The phylogeneteic relationships in genera Calligonum and Pteropyrum (Polygonaceae) are reconstructed using 30 vegetative and reproductive morphological characters. The data matrix comprised 18 species of Calligonum and 3 species of Pteropyrum plus 2 Atraphaxis species representing outgroups. The analyses were conducted using maximum parsimony approach with characters treated both equally weighted and reweighted by rescaled consistency index. The results revealed that Calligonum is monophyletic. But Pteropyrum is appeared to be monophyletic after reweighting procedure. In both analyses Calligonum is composed of two clades, one is including the winged fruit species (sect. Pterococcus) and the second including the bristled fruit ones (sect. Calligonum) encompassing the monotypic sect. Calliphysa (Calligonum junceum). Of 30 characters analyzed, seven are synapomorphic for both genera. Six characters in Calligonum and one in Pteropyrum were genus specific. The remainder of characters was evolved homoplasiously (or ambiguously) among thsese taxa.

Solmaz Tavakkoli

Papers

The phylogeny of Calligonum and Pteropyrum (Polygonaceae) based on nuclear ribosomal DNA ITS and chloroplast trnL-F sequences

Molecular phylogeny of Atraphaxis and the woody Polygonum species (Polygonaceae): taxonomic implications based on molecular and morphological evidence

Atraphaxis radkanensis (Polygonaceae), a New Species from Iran

Archive of SID MORPHOLOGICAL CLADISTIC ANALYSIS OF CALLIGONUM AND PTEROPYRUM (POLYGONACEAE) IN IRAN