Alexander P. Sukhorukov

Molecular phylogeny of Atripliceae (Chenopodioideae, Chenopodiaceae): Implications for systematics, biogeography, flower and fruit evolution, and the origin of C4 photosynthesis.

UNLABELLED PREMISE OF THE STUDY Atripliceae (Chenopodiaceae), including Atriplex (300 spp.) as the largest genus of the family, are an ecologically important group of steppes and semideserts worldwide. Relationships in Atripliceae are poorly understood due to obscure and potentially convergent morphological characters. • METHODS Using sequence variation of two chloroplast markers (rbcL gene, atpB-rbcL spacer) and one nrDNA marker (ITS) analyzed with BEAST, we investigated the systematics and biogeography of Atripliceae. We surveyed flower morphology and fruit anatomy to study the evolution of flowers and fruits in the tribe. • KEY RESULTS Female flowers with persistent foliar cover (the diagnostic character of traditional Atripliceae) evolved three times in Chenopodioideae, in Atripliceae s.s., Axyrideae, and Spinacia. Atripliceae s.s. started to diversify during the Early Miocene in Eurasia, separating into the Archiatriplex and the Atriplex clades. The former consists of eight species-poor, disjunct, and morphologically heterogeneous genera and is likely a relictual lineage. The Atriplex clade comprises the majority of species and evolved one C(4) lineage 14.1-10.5 Ma, which diversified rapidly worldwide. The C(4) Atriplex entered North America during the Middle/Late Miocene and spread to South America subsequently. Australia was colonized by two C(4) lineages both arriving during the Late Miocene. One of them diversified rapidly, giving rise to most Australian Atriplex species. • CONCLUSIONS Atripliceae s.s. comprise Archiatriplex, Atriplex, Exomis, Extriplex, Grayia, Halimione, Holmbergia, Manochlamys, Proatriplex, and Stutzia. Microgynoecium is included based on morphology but only weak molecular support. Axyris, Krascheninnikovia, and Ceratocarpus (here described as Axyrideae) and Spinacia are excluded from Atripliceae.

Fruit and Seed Anatomy of Chenopodium and Related Genera (Chenopodioideae, Chenopodiaceae/Amaranthaceae): Implications for Evolution and Taxonomy

A comparative carpological study of 96 species of all clades formerly considered as the tribe Chenopodieae has been conducted for the first time. The results show important differences in the anatomical structure of the pericarp and seed coat between representatives of terminal clades including Chenopodium s.str.+Chenopodiastrum and the recently recognized genera Blitum, Oxybasis and Dysphania. Within Chenopodium the most significant changes in fruit and seed structure are found in members of C. sect. Skottsbergia. The genera Rhagodia and Einadia differ insignificantly from Chenopodium. The evolution of heterospermy in Chenopodium is discussed. Almost all representatives of the tribe Dysphanieae are clearly separated from other Chenopodioideae on the basis of a diverse set of characteristics, including the small dimensions of the fruits (especially in Australian taxa), their subglobose shape (excl. Teloxys and Suckleya), and peculiarities of the pericarp indumentum. The set of fruit and seed characters evolved within the subfamily Chenopodioideae is described. A recent phylogenetic hypothesis is employed to examine the evolution of three (out of a total of 21) characters, namely seed color, testa-cell protoplast characteristics and embryo orientation.

One-Seeded Fruits in the Core Caryophyllales: Their Origin and Structural Diversity

The core Caryophyllales consist of approximately 30 families (12 000 species) distributed worldwide. Many members evolved one-seeded or conjoined fruits, but their origin and structural diversity have not been investigated. A comparative anatomical investigation of the one-seeded fruits within the core Caryophyllales was conducted. The origin of the one-seeded fruits and the evolutionary reconstructions of some carpological characters were traced using a tree based on rbcl and matK data in order to understand the ancestral characters and their changes. The one-seeded fruit type is inferred to be an ancestral character state in core Caryophyllales, with a subsequent increase in the seed number seen in all major clades. Most representatives of the ‘Earlier Diverging’ clade are distinguished in various carpological traits. The organization of the pericarp is diverse in many groups, although fruits with a dry, many-layered pericarp, consisting of sclerenchyma as outer layers and a thin-walled parenchyma below, with seeds occupying a vertical embryo position, are likely ancestral character states in the core Caryophyllales clade. Several carpological peculiarities in fruit and seed structure were discovered in obligate one-seeded Achatocarpaceae, Chenopodiaceae, Nyctaginaceae, Seguieriaceae and Sarcobataceae. The horizontal embryo evolved in only certain groups of Chenopodiaceae. The bar-thickening of endotegmen cells appears to be an additional character typical of core Caryophyllales. The syncarpy-to-lysicarpy paradigm in Caryophyllaceae needs to be reinterpreted.

Fruit anatomy and its taxonomic significance in Corispermum (Corispermoideae, Chenopodiaceae)

Abstract Sukhorukov, A. P.: Fruit anatomy and its taxonomic significance in Corispermum (Corispermoideae, Chenopodiaceae). — Willdenowia 37: 63–87. — ISSN 0511-9618;

Taxonomic notes on Dysphania and Atriplex (Chenopodiaceae)

Abstract Sukhorukov A. P.: Taxonomic notes on Dysphania and Atriplex (Chenopodiaceae). — Willdenowia 42: 169–180. December 2012. — Online ISSN 1868-6397;

Axyris (Chenopodiaceae s.str. or Amaranthaceae s.l.) in the Himalayas and Tibet

Abstract Sukhorukov A. P.: Axyris (Chenopodiaceae s.str. or Amaranthaceae s.l.) in the Himalayas and Tibet. — Willdenowia 41: 75–82. — Online ISSN 1868-6397;

Fruit anatomy of the genus Anabasis (Salsoloideae, Chenopodiaceae)

The fruit anatomy and morphology of 22 representatives of the genus Anabasis L. were studied, with the aim of clarifying the taxomomic importance of carpological characters in the genus. As shown in cross-sections, the pericarp of Anabasis is differentiated into the following four zones: (i) outer epidermis, (ii) subepidermal hydrated parenchyma, (iii) crystalliferous layer with lignified U-shaped cell walls and (iv) inner epidermis. Anatomical differences mainly relate to the outer epidermal structure. Fruit anatomy does not confirm the separation of the genera Brachylepis and Esfandiaria. A combination of carpological characteristics separates A. annua and A. setifera from the other species studied. Also, characters of reproductive organs in representatives of Anabasis are shown. When vegetative and reproductive features are considered, the genus Fredolia appears rather distant from Anabasis s.l. The pericarp histology of almost all the Salsoloideae (incl. Anabasis) is fully presented in the upper third of the fruit. In the lower parts of the fruit, some histological layers are either reduced or absent altogether. On the basis of the anatomical structures in the upper third of the fruit, the common carpological features of the Salsoloideae can be defined. These include a pericarp consisting of several, usually well-differentiated layers and the presence of crystalliferous cells with U-shaped walls. The two- to four-cell layered outer epidermis of three Anabasis representatives (A. eriopoda, A. jaxartica, A. turkestanica) seems to be an apomorphic feature in the Salsoloideae. The seed coat is thin (two cell layers thick) and non-differentiated. Owing to the pericarp and seedcoat structure, the fruit and seed covers have low resistance to environmental degradation processes and, therefore, are unlikely to be found among fossil remnants.

A rapid and cost-effective method for DNA extraction from archival herbarium specimens

Here we report a rapid and cost-effective method for the extraction of total DNA from herbarium specimens up to 50-90-year-old. The method takes about 2 h, uses AMPure XP magnetic beads diluted by PEG-8000-containing buffer, and does not require use of traditional volatile components like chloroform, phenol, and liquid nitrogen. It yields up to 4 μg of total nucleic acid with high purity from about 30 mg of dry material. The quality of the extracted DNA was tested by PCR amplification of 5S rRNA and rbcL genes (nuclear and chloroplast DNA markers) and compared against the traditional chloroform/isoamyl alcohol method. Our results demonstrate that the use of the magnetic beads is crucial for extraction of DNA suitable for subsequent PCR from herbarium samples due to the decreasing inhibitor concentrations, reducing short fragments of degraded DNA, and increasing median DNA fragment sizes.

A new species of Arthrocnemum (Salicornioideae: Chenopodiaceae-Amaranthaceae) from West Africa, with a revised characterization of the genus

Abstract A new species Arthrocnemum franzii Sukhor. is described from the Republic of Cape Verde (Sal, Maio and Boa Vista islands). The species is recognized as distinct from Arthrocnemum macrostachyum (Moric.) K.Koch based on differences in the perianth shape, length of the anthers and style, and seed-coat ornamentation. No seed heteromorphism is observed within individuals of either species, despite differences in the size of the central and lateral flowers within each cyme (heteroanthocarpy). The North American Arthrocnemum subterminale (Parish) Standl. (syn. Salicornia subterminalis Parish) is morphologically distant from Eurasian Arthrocnemum or Salicornia/Sarcocornia group and should be excluded from these genera. The genus Arthrocnemum now comprises only two species (A. macrostachyum and A. franzii), distributed in the Mediterranean area, Macaronesia, West Tropical Africa and the Saharo-Arabian region. A generic description is here elaborated, clearly delimiting Arthrocnemum from morphologically similar species of Sarcocornia. A list of current species previously considered as Arthrocnemum is provided. It is argued that the taxonomic status of Salicornia mucronata Lag. (1817), mentioned in some references as a synonym of Salicornia macrostachya Moric. (1820) [≡Arthrocnemum macrostachyum (Moric.) K.Koch], is indeed a new synonym of Anabasis articulata (Forssk.) Moq. (subf. Salsoloideae). Both names merged with Arthrocnemum macrostachyum – Salicornia virginica Forssk. and Arthrocnemum glaucum (Delile) Ung.-Sternb. var. fasciculatum Sennen were lectotypified. The typification of the genus Arthrocnemum has so far been lacking and requires a special proposal with a conserved type.

Taxonomic significance of seed morphology in the genus Mollugo s.l. (Molluginaceae)

ABSTRACTThe genus Mollugo L. comprises ca. 35 species distributed throughout the tropics, and it is clearly polyphyletic. The seed morphology and ornamentation of 27 Mollugo representatives is studied with regard to their significance for systematics and taxon delimitation. The species belonging to the “M. cerviana” and “M. fragilis” groups, as well as M. tenella, are characterized by D-shaped or roundish seeds, whereas other taxa have reniform seeds. The seed ornamentation can be considered to be one of the most valuable characters for disentangling the taxonomic diversity in the genus. Mollugo cerviana shares the same reticulate ornamentation with M. namaquensis, M. pusilla, M. tenella and M. tenuissima, while the smooth surface is peculiar to M. fragilis, M. spathulata and M. walteri. The close relationship of M. fragilis and relatives to Hypertelis spergulacea is carpologically supported. Some taxa share a papillate ornamentation (M. decandra, M. floriana, M. molluginis, M. nudicaulis, M. pentaphylla,...