A late Pleistocene long pollen record from Lake Urmia, NW Iran

A palynological study based on two 100-m long cores from Lake Urmia in northwestern Iran provides a vegetation record spanning 200 ka, the longest pollen record for the continental interior of the Near East. During both penultimate and last glaciations, a steppe of Artemisia and Poaceae dominated the upland vegetation with a high proportion of Chenopodiaceae in both upland and lowland saline ecosystems. While Juniperus and deciduous Quercus trees were extremely rare and restricted to some refugia, Hippophaë rhamnoides constituted an important phanerophyte, particularly during the upper last glacial sediments. A pronounced expansion in Ephedra shrub-steppe occurred at the end of the penultimate late-glacial period but was followed by extreme aridity that favoured an Artemisia steppe. Very high lake levels, registered by both pollen and sedimentary markers, occurred during the middle of the last glaciation and upper part of the penultimate glaciation. The late-glacial to early Holocene transition is represented by a succession of Hippophaë, Ephedra, Betula, Pistacia and finally Juniperus and Quercus. The last interglacial period (Eemian), slightly warmer and moister than the Holocene, was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern European pollen sequences

Lithology and palynology of cave floor sediment cores from Wakulla Spring, Wakulla County, Florida

Five short bottom sediment cores taken in Wakulla Spring Wakulla County, Florida, were described lithologically and sampled for palynological study. Four of the cores were recoveredfrom sediments at the spring cave entrance (130 feet water depth). One core was taken in a fossil vertebrate bone bed, 280 feet distance into the main spring cave at a water depth of 240 feet. Sediments in the cores are composed of alternating intervals of quartz sand and calcilitite, containing freshwater diatoms, freshwater mollusk shells and plant remains. The predominant pollen present in all cores consists of a periporate variety typical of the herb families Chenopodiaceae and Amaranthaceae. Arboreal flora, typical of the area surrounding the spring today, represent a very low percentage of thle pollen assemblage in the cores. Clustered Chenopod-Amaranth type pollen observed in one core suggest minimal transport prior to deposition, and indicate that the bottom sediments in the cave may be essentially In situ. An absence of exotic flora suggests a Quaternary age for the sediments. (PDF contains 11 pages.

Phylogeny and morphological evolution of the Chenopodiaceae-Amaranthaceae alliance

Phylogenetic analysis of plastid encoded ndhF coding sequences for the Chenopodiaceae-Amaranthaceae alliance reveals a monophyletic Chenopodiaceae-Amaranthaceae clade sister to Achatocarpaceae. The Chenopodiaceae-Amaranthaceae-Achatocarpaceae clade is in turn sister to the Caryophyllaceae, the Chenopodiaceae-Amaranthaceae-Achatocarpaceae-Caryophyllaceae clade forming a separate lineage within order Caryophyllales. The Chenopodiaceae as currently circumscribed is paraphyletic and the alliance breaks into a polytomy of four major clades: (i) Amaranthaceae-Polycnemoideae, (ii) Chenopodieae-Atripliceae, (iii) SalicornioideaeSalsoloideae, and (iv) Beteae. Character-state optimizations of morphological characters mapped onto ndhF sequence derived phylogenies reveal phylogenetically significant patterns of character-state distribution. Morphological investigations also revealed a previously undetected branching pattern in the Gomphrenoideae, which is here described, illustrated, and discussed. Morphological analyses of Amaranthus led to the discovery of a previously undescribed species, which is here described and illustrated and its morphological affinities discussed

Terrestrial climate variability and seasonality changes in the Mediterranean region between 15 000 and 4000 years BP deduced from marine pollen records

Pollen-based climate reconstructions were performed on two high-resolution pollen marines cores from the Alboran and Aegean Seas in order to unravel the climatic variability in the coastal settings of the Mediterranean region between 15 000 and 4000 years BP (the Lateglacial, and early to mid-Holocene). The quantitative climate reconstructions for the Alboran and Aegean Sea records focus mainly on the reconstruction of the seasonality changes (temperatures and precipitation), a crucial parameter in the Mediterranean region. This study is based on a multi-method approach comprising 3 methods: the Modern Analogues Technique (MAT), the recent Non-Metric Multidimensional Scaling/Generalized Additive Model method (NMDS/GAM) and Partial Least Squares regression (PLS). The climate signal inferred from this comparative approach confirms that cold and dry conditions prevailed in the Mediterranean region during the Oldest and Younger Dryas periods, while temperate conditions prevailed during the Bølling/Allerød and the Holocene. Our records suggest a West/East gradient of decreasing precipitation across the Mediterranean region during the cooler Late-glacial and early Holocene periods, similar to present-day conditions. Winter precipitation was highest during warm intervals and lowest during cooling phases. Several short-lived cool intervals (i.e. Older Dryas, another oscillation after this one (GI-1c2), Gerzensee/Preboreal Oscillations, 8.2 ka event, Bond events) connected to the North Atlantic climate system are documented in the Alboran and Aegean Sea records indicating that the climate oscillations associated with the successive steps of the deglaciation in the North Atlantic area occurred in both the western and eastern Mediterranean regions. This observation confirms the presence of strong climatic linkages between the North Atlantic and Mediterranean regions

Rubisco evolution in C4 eudicots: an analysis of Amaranthaceae sensu lato

BACKGROUND Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyses the key reaction in the photosynthetic assimilation of CO₂. In C₄ plants CO₂ is supplied to Rubisco by an auxiliary CO₂-concentrating pathway that helps to maximize the carboxylase activity of the enzyme while suppressing its oxygenase activity. As a consequence, C₄ Rubisco exhibits a higher maximum velocity but lower substrate specificity compared with the C₃ enzyme. Specific amino-acids in Rubisco are associated with C₄ photosynthesis in monocots, but it is not known whether selection has acted on Rubisco in a similar way in eudicots. METHODOLOGY/PRINCIPAL FINDINGS We investigated Rubisco evolution in Amaranthaceae sensu lato (including Chenopodiaceae), the third-largest family of C₄ plants, using phylogeny-based maximum likelihood and Bayesian methods to detect Darwinian selection on the chloroplast rbcL gene in a sample of 179 species. Two Rubisco residues, 281 and 309, were found to be under positive selection in C₄ Amaranthaceae with multiple parallel replacements of alanine by serine at position 281 and methionine by isoleucine at position 309. Remarkably, both amino-acids have been detected in other C₄ plant groups, such as C₄ monocots, illustrating a striking parallelism in molecular evolution. CONCLUSIONS/SIGNIFICANCE Our findings illustrate how simple genetic changes can contribute to the evolution of photosynthesis and strengthen the hypothesis that parallel amino-acid replacements are associated with adaptive changes in Rubisco.This research was funded by NERC (http://www.nerc.ac.uk/; grant number NE/H007741/1)

Corrigendum to “Pollen-based paleoenvironmental and paleoclimatic change at Lake Ohrid (south-eastern Europe) during the past 500 ka” published in Biogeosciences, 13, 1423–1437, 2016

In this corrigendum we report an updated pollen record from the Lake Ohrid DEEP site spanning the past 500 ka whereby we have reprocessed and re-analyzed 104 samples affected by chemical procedure problems that occurred in one palynological laboratory. Firstly, these samples were affected by the use of wrong containers, causing in- adequate settling of particles at the set centrifuging speed. Secondly, HCl and HF treatments were combined without the prescribed intermediate centrifuging and decanting steps. The inaccuracy in the protocol resulted in the loss of smaller pollen grains and in the overrepresentation of bisaccate ones in most of the re-analyzed samples. We therefore provide an updated set of figures with the new data and have revised the description of the results, discussion and conclusions re- ported in Sadori et al. (2016) where necessary. We stress that the majority of the original results and conclusions remain valid, while the records’ reliability and resolution have improved as 12 samples that had been omitted in the original study because of low count sums are now included in the revised dataset (Sadori et al., 2018)

Saltbush-associated Asphondylia species (Diptera: Cecidomyiidae) in the Mediterranean Basin and their chalcidoid parasitoids (Hymenoptera: Chalcidoidea)

Numerous species of gall midges (Diptera: Cecidomyiidae) have been recorded from saltbush (Chenopodiaceae: Atriplex) around the world but only 11 of them belong to the large cecidomyiid genus Asphondylia. Of these, two species were de-scribed in the late 19th century from complex bud galls on Atriplex halimus in the Mediterranean Basin. In the present study Asphondylia punica is redescribed, A. conglomerata is synonymized with it, and Asphondylia scopuli is described from Atriplex lanfrancoi, an endemic plant to the Maltese Islands. Descriptions are accompanied by information about the galls and life history of the gall midges, and a review of the parasitic Hymenoptera associated with A. scopuli is provided. Four species of parasitoids were found and attributed to the families Eurytomidae, Pteromalidae, Eupelmidae and Eulophidae, of which the pteromalid Mesopolobus melitensis is described as new.peer-reviewe

Notes on the germination of the endangered species Sclerolaena napiformis (Chenopodiaceae)

Sclerolaena napiformis is found on fertile plains in northern Victoria and southern New South Wales and is endangered Australia-wide. Introductory work on its germination shows that seeds cannot germinate until the woody fruit has broken down. The seeds tolerate a wide range of temperatures for germination, suggesting that germination occurs regardless of season if sufficient rain falls. Seed ageing effects reduce seed viability, but some seed is still viable after two years storage. Flower buds first appear 21 weeks from germination and some fruits have matured by week 29. In the field, plants die back to their taproots in late autumn and resprout in spring. Ninety percent of tagged plants were still alive two years later. The physiological seed dormancy imposed by an intact fruit wall provides a mechanism for the development of persistent soil seed banks. Work on the ecological significance of such banks is needed. The literature on interactions between Sclerolaena fruit and seed biology and ants is briefly reviewed

Morphological and immunochemical characterization of the pollen grains of Chenopodium album L. (Chenopodiaceae) in a temperate urban area in Argentina

Chenopodium album es una hierba cosmopolita, anual, muy polimórfica, que crece en forma espontánea en baldíos con suelos modificados de los barrios periféricos de Bahía Blanca. En esta ciudad, el periodo de floración es principalmente entre febrero y marzo, que coincide con la mayor concentración de este tipo de polen en la atmósfera. El objetivo de este estudio fue caracterizar morfológica e inmunoquímicamente a los granos de polen de Chenopodium album obtenidos en diferentes zonas del área urbana de la Bahía Blanca. Las muestras fueron colectadas en tres zonas de la ciudad. La estructura y la morfología de los granos fueron analizados con microscopía óptica y electrónica. Los perfiles proteicos y antigénicos fueron estudiados mediante Tricine-SDS-PAGE y western blot, empleando un suero policlonal obtenido en conejo. El análisis morfológico mostró diferencias significativas en relación al diámetro de los granos de polen en una de las áreas estudiadas. En esa misma área se encontraron diferencias en la expresión de proteínas, aunque el perfil antigénico fue conservado. Estas variaciones en la morfología y en el perfil proteico podrían ser causadas por los efectos de las condiciones ambientales sobre el polen y la presencia de contaminantes urbanos provenientes del tráfico vehicular.Chenopodium album is a very polymorphic, cosmopolitan, annual herb that grows spontaneously in modified soils in wasteland in the outlying urban zones of Bahía Blanca. In this city, the flowering period is mainly during February and March, which coincides with the highest concentrations of this pollen type in the atmosphere of the city. The objective of this study was to characterize the pollen grains of Chenopodium album, both morphologically and immunochemically, that were obtained from three different zones in the urban area of Bahía Blanca. Samples were collected from the three separate zones in the city that were far apart. The structure and morphology of the grains were analyzed using light and electron microscopy. The protein and antigenic profiles were studied with Tricine-SDS-PAGE and western blot with a polyclonal rabbit serum, respectively. The morphological analysis showed significant differences in relation to the diameters of the pollen grains in one of the studied areas. Differences in the protein expression were seen for the same area although the antigenic profile was conserved. The variations in the morphology and the protein profile may be caused by the effect of environmental conditions on the pollen, and the presence of urban contaminants from vehicular traffic.Fil: Bianchimano, Andrea Susana. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Murray, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Aztiria, María Eugenia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Inmunología; ArgentinaFil: Montes, Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Calfuán, Melina Lorena. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Prat, María Inés. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin