Ozone‐induced reductions in below‐ground biomass: an anatomical approach in potato

Potato plants were grown in open‐top chambers under three ozone concentrations during two complete cropping seasons (93 and 77 d in 2004 and 2005, respectively). The effects of chronic exposure to ozone on leaf anatomy, cell ultrastructure and crop yield were studied. Severe cell damage was found, even at ambient ozone levels, mainly affecting the spongy parenchyma and areas near the stomata. Damage to the cell wall caused loss of cell contact, and loss of turgor pressure due to tonoplast disintegration, contributed to cell collapse. Phloem sieve plates were obstructed by callose accumulation, and damaged mesophyll cells increased their starch stores. Tuber yield fell sharply (24–44%), due to the biggest tubers becoming smaller, which affected commercial yield. These anatomical findings show the mechanisms of ozone effect on assimilate partitioning, and thus crop yield decrease, in potato. Further implications of ozone causing reductions in below‐ground biomass are also discussed.     

An integrative taxonomic revision of the Tarentola geckos (Squamata,Phyllodactylidae) of the Cape Verde Islands

Recent phylogeographical analyses using mitochondrial DNA (mtDNA) sequences indicate that the Tarentola geckos from the Cape Verde archipelago originated from a propagule that dispersed from the Canary Islands approximately 7.7 Mya and that underwent a fast evolutionary radiation. Molecular analyses carried out to date clearly show some incongruences with the current taxonomy of Tarentola from the Cape Verde Islands, with some species being paraphyletic or polyphyletic, and several independently evolving lineages needing formal taxonomic recognition. The aim of this study was to clarify the systematics of this group to unravel its taxonomy by applying an integrative approach based on information from three independent sources: mtDNA, nuclear genes, and morphology. As a result of this taxonomic revision, two novel species for the islands of S. Nicolau and Fogo are described and eight subspecies are upgraded to species level. Moreover, an identification key for the genus Tarentola from the Cape Verde archipelago is presented. This study reconciles taxonomy and phylogeny in this group, provides a better understanding of diversity patterns, new insights on evolutionary hypotheses, and supports the basic framework for the future management and conservation of this unique reptile radiation. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 328–360.     

Ionic Requirements for Catecholamine Aggregating Actions on the Teleost Poecilia reticulata Melanophores

Norepinephrine (NE) and phenylephrine (Phe) were employed to study the ionic requirements for alpha adrenoceptor activation in the teleost Poecilia reticulata melanophores. As expected the beta adrenoceptor blocker, propranolol, increased the sensitivity of the preparation to NE (5.8 times), and was therefore employed in all the experimental procedures. Neither cocaine (a neuronal uptake blocker) nor dexamethasone (an extraneuronal uptake blocker) enhanced the sensitivity of the preparation to NE, suggesting that these inactivating mechanisms would not play a role in P. reticulata pigmentary system. However, in the absence of calcium, the dose-response curve (DRC) to NE was displaced to the left about 3.5 times, whereas the DRC to Phe was not affected. These results indicate that a neuronal uptake is active, but was not demonstrated by the classical pharmacological tools, probably due to an assymmetric display of the nervous endings. The DRC to NE was rightward displaced (14.1 times) in the presence of the calcium channel blocker Verapamil, whereas the DRC to Phe was not affected. These data suggest that P. reticulata melanophores possess a mixed population of alpha₁ and alpha₂ adrenoceptors, the activation of the latter eliciting an extracellular calcium influx. In sodium-free saline, the DRC to NE was rightward shifted (6.6 times) and the response to Phe was impaired in such a way that the maximal response was not achieved. The DRC to both NE and Phe were rightward displaced (7.9 and 2.7 times respectively) in the presence of the sodium channel blocker tetrodotoxin (TTX) 10^?7M. In potassium-free saline, the melanophore sensitivity to Phe was increased, whereas the responses to NE were not affected, suggesting a differential sensitivity of the two alpha adrenoceptor subtypes to the resulting membrane hyperpolarization. Based on the literature and on our data we propose that P. reticulata melanophores possess a mixed population of alpha₁ and alpha₂ receptors. The activation of both subtypes of alpha adrenoceptors elicits a Na⁺ ion influx through TTX-sensitive sodium channels. The stimulation of alpha₂ adrenoceptors also requires an extracellular calcium influx, through the opening of slow calcium channels.     

A new agenda for blue agave landraces: food,energy and tequila

Agave tequilana Weber (Rigidae, Agavaceae), blue agave, is a native Mexican plant that has been associated with tequila since the 17th century. The tequila industry has matured over time and now has a geographical indication (Denominación de Origen; DOT). The tequila industry has grown substantially in the last 15 years (19.82% annual increase between 1995 and 2008), resulting in an increase in agave production and associated residue (leaves) and bagasse that can be used for second‐generation biofuels. At a time when the biofuel industry is undergoing unprecedented changes, with diversified demand and predictions of increased competitiveness, this paper presents a review of agave landraces that have been affected by tequila production but may be beneficial for a biofuel industry. Conventional botanical studies have revealed domestication syndromes in races related to blue agave (‘azul listado’, ‘sigüín’ and ‘pata de mula’) specifically for production of fructans in the plant core as would be expected in mezcal agaves (including those used for tequila). Some others, such as the ‘moraleño’ and ‘bermejo’ cultivars (Sisalanae) show domestication syndrome only in the fibers, while others, such as ‘chato,’A. americana L. subtilis (Americanae) show domestication syndrome in fructans and fibers and ‘zopilote,’A. rhodacantha (Rigidae) a relatively low domestication syndrome. No specimens of the cultivars named ‘mano larga’, ‘mano anchaque’ and ‘cucharo’ were found in the Tequila Region of Origin (Western Mexico). The genetic resources from landraces ignored by the tequila industry may be valuable for both ethanol production and conservation.     

Conservation and versatility of a new set of primers for long‐PCR amplification of complete insect mitochondrial genomes based on Haematobia irritans mtDNA sequences

The amplification of complete mitochondrial genomes by long PCR (polymerase chain reaction) has been a major contribution to the large‐scale sequencing of arthropodan mitochondrial genomes. In this work, we designed six conserved long‐PCR primers to successfully recover the entire mitochondrial genome of the horn fly Haematobia irritans (Diptera: Muscidae) in two overlapping fragments. The conservation and versatility of these primers were tested for 17 other species from four major insect orders: Diptera (14), Coleoptera (1), Lepidoptera (1) and Hymenoptera (1). The amplification of complete mitochondrial genomes in orders other than Diptera suggested an even broader application of these primers, especially within the Hexapoda.     

First record of the raccoon dog (Nyctereutes procyonoides Gray, 1834) in the former Yugoslav Republic of Macedonia

An adult male raccoon dog (Nyctereutes procyonoides Gray, 1834) run over by a car was found on September 6, 2002, in the central part of the Former Yugoslav Republic of Macedonia (UTM: EM 54). This is the first record of this species on the territory of the FYRM, and the southernmost point of its European range so far. This finding indicates a range extension of the raccoon dog on the Balkan Peninsula.