Seed micromorphology in the genus Neotinea Rchb.f. (Orchidaceae, Orchidinae)

The ultrastructure of testa seed in the genus Neotinea (Orchidaceae, Orchidinae) was examined for the first time. The morphology of the seed and of the anticlinal and periclinal walls was analysed by scanning electron microscopy. Quantitative data concerning the length and width of the seed and embryo, seed and embryo volume, free air space, and number of cells along the longitudinal axis are presented. In all species, the seeds are fusiform in shape with transverse ridges on the inner periclinal walls. This ornamentation pattern is characteristic for the genus Neotinea . It is a good diagnostic value supporting the monophyly of this genus, which has recently been proposed by several authors.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 133–140.     

A metabolomic study in oats (Avena sativa) highlights a drought tolerance mechanism based upon salicylate signalling pathways and the modulation of carbon,antioxidant and photo‐oxidative metabolism

Although a wealth of information is available on the induction of one or several drought‐related responses in different species, little is known of how their timing, modulation and crucially integration influence drought tolerance. Based upon metabolomic changes in oat (Avena sativa L.), we have defined key processes involved in drought tolerance. During a time course of increasing water deficit, metabolites from leaf samples were profiled using direct infusion–electrospray mass spectroscopy (DI‐ESI‐MS) and high‐performance liquid chromatography (HPLC) ESI‐MS/MS and analysed using principal component analysis (PCA) and discriminant function analysis (DFA). The involvement of metabolite pathways was confirmed through targeted assays of key metabolites and physiological experiments. We demonstrate an early accumulation of salicylic acid (SA) influencing stomatal opening, photorespiration and antioxidant defences before any change in the relative water content. These changes are likely to maintain plant water status, with any photoinhibitory effect being counteracted by an efficient antioxidant capacity, thereby representing an integrated mechanism of drought tolerance in oats. We also discuss these changes in relation to those engaged at later points, consequence of the different water status in susceptible and resistant genotypes.     

Evolutionary history of mole rats (genus Nannospalax) inferred from mitochondrial cytochrome b sequence

Mole rats (genus Nannospalax) display prolific chromosomal variation with more than 50 distinct cytotypes. These cytotypes are largely indistinguishable morphologically, are mainly allopatric and their taxonomic ranking is contradictory. We established a cytochrome b phylogeny for 15 cytotypes belonging to all three species recognized on morphological grounds (morphospecies): N. leucodon, N. xanthodon and N. ehrenbergi. Phylogenetic reconstructions yielded two highly divergent groups which are in agreement with the current division into two subgenera (Nannospalax and Mesospalax). The former comprised samples from south‐eastern Turkey, Israel and Egypt (the morphospecies N. ehrenbergi). Basal dichotomy within Mesospalax remained unresolved and the putative sister position of N. leucodon against the two lineages of N. xanthodon was not supported in our analysis. Net divergences between sister cytotypes were low (< 2.0%) and two N. leucodon cytotypes were not even reciprocally monophyletic. Among the three morphospecies, the genetic diversity was lowest in N. leucodon (2.4% ± 0.3%), highest in N. xanthodon (8.8% ± 0.7%) and intermediate in N. ehrenbergi (5.0% ± 0.5%). Our results show that associations between genetic and chromosomal variation are not widespread and common in mole rats, and therefore refute the generalization of a ‘cytotype‐equals‐species’ approach. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 446–455.     

RE-ASSESSMENT OF THE TYPE COLLECTIONS OF CORALLINALEAN GENERA (CORALLINALES, RHODOPHYTA) DESCRIBED BY V. P. MASLOV

Abstract:  From 1935 to 1962 Maslov published two monographs and several other papers on the taxonomy of fossil calcareous algae of diverse ages from the large geographical area of the former USSR. Among many other taxa, he described five new genera ( Solenophyllum , Palaeophyllum , Mesolithon , Bicorium and Tomilithon , as a subgenus of Parachaetetes Deninger) which he attributed to the Corallinaceae, and the new genus Karpathia , which he included in the Squamariaceae. Type material of these taxa, except for Mesolithon , is housed in the Geological Institute of the Russian Academy of Sciences, Moscow. Re-examination of the genus types from a modern perspective of coralline algal taxonomy shows that Karpathia is a validly published genus of corallinaceans (subfamily Mastophoroideae) to which several Cenozoic fossil species can be assigned. In contrast, the holotype of P. elegans , the type species of Palaeophyllum , cannot be assigned to any subfamily within the Corallinaceae and its preserved features are inadequate for confidently delimiting a separate genus. Solenophyllum is a valid genus in which Palaeozoic representatives of Corallinales formerly attributed to Parachaetetes Deninger can be included. Tomilithon is considered a younger heterotypic synonym of Solenophyllum . The algal nature of the bioclasts in the type of Bicorium is uncertain.     

Natives Making Nation: Gender, Indigeneity, and the State in the Andes

Natives Making Nation: Gender, Indigeneity, and the State in the Andes. Andrew Canessa, ed. Tucson: University of Arizona Press, 2005. 201 pp.