Susceptibilidad de híbridos de Populus spp. al ataque de áfidos y roya en tres localidades de Chile

Ramirez, CC (reprint author), Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, Chile.In the last few years an increasing interest on species and hybrids of the genus Populus has occurred in Chile. However, such plantations are strongly affected by pest and diseases. With the aim to identify potentially resistant (or less susceptible) hybrids of the genus Populus, the susceptibility of some poplar hybrids growing in experimental nurseries in Southern-Center Chile to the aphid Chaitophorus leucomelas Koch and to the rust Melampsora spp. was assessed. Results showed that aphid abundance was higher in the month of March, particularly in Coinco (O'Higgins Region) and lower in Pillanlelbun (Los Rios Regions) and Yumbel (Biobio Region). In Pillanlelbun the most susceptible hybrid to aphids was TDxTD [(P. trichocarpa x P. deltoides) x (P. trichocarpa x P. deltoides)], and the less susceptible ones were TDxD [(P. trichocarpa x P. deltoides) x P. deltoides], TxN (P. trichocarpa x P. nigra), TMxTM [(P. trichocarpa x P. maximowitzii) x (P. trichocarpa x P. maximowitzii)] and TDxT [(P. trichocarpa x P. deltoides) x P. trichocarpa]. Hybrid TxN (P. trichocarpa x P. nigra) was the most susceptible to rust in all testing sites, while the less susceptible hybrids were TDxT [(P. trichocarpa x P. deltoides) x P. trichocarpa], TDxD [(P. trichocarpa x P. deltoides) x P. trichocarpa] and TDxT [(P. trichocarpa x P. deltoides) x P. trichocarpa]. These susceptibilities varied among localities, particularly on aphids. Genetic and environmental factors accounting for by these results are discussed

A novel K+ channel blocking toxin from Tityus discrepans scorpion venom

AbstractA novel toxin (TdK1) was purified from the venom of the scorpion Tityus discrepans, sequenced and functionally characterized. It contains 37 amino acid residues and blocks reversible the shakerB K+ channel expressed in SF9 cells with a Kd in the order of 280 nM. The proposed systematic nomenclature for this peptide is α-KTx4.3

Energía y productos de hidrólisis a partir de cultivos industriales y forestales

Se caracterizan química y energéticamente diversas especiesvegetales de elevada producción de biomasa (Eucalyptus globulus, tallos de girasol, Chamaecitysus proliferus, Paulownia fortunei, Leucaena diversifolia y Arundo donax) y se estudia el proceso de autohidrólisis en condiciones no isotermas en un marco general de evaluación de la valorización por fraccionamiento y aprovechamiento integral de las fracciones lignocelulósicas con posterior aprovechamiento energético de la fase sólida post-hidrólisis. Los procesos de autohidrólisis se han revelado particularmente interesantes en el caso de las especies madereras estudiadas frente a las especies herbáceas con variaciones en la extracción de la fracción de xilano a 180ºC entre el 19,7% de Eucalyptus globulus y el 36,8% de Leucaenadiversifolia y a 200ºC entre el 57,9% de Paulownia fortunei y el 79,1% de Chamaecytisus proliferus. Las especies madereras de corta rotación de cultivo ensayadas se manifiestan más susceptibles que la especie de referencia (Eucalyptus globulus) al proceso de autohidrólisis a bajas temperaturas. La explotación de las especies madereras de corta rotación ensayadas por combustión directa de la fracción sólida post-autohidrólisis a 200ºC aporta, además de la valorización inherente a los oligómeros y monosacáridos de la fracción líquida, un aumento del poder calorífico relativo de la fracción sólida post-autohidrólisis del 3,4% en Paulownia fortunei y 6,7% en Leucaena diversifolia

Gene expression varies within and between enzootic and epizootic lineages of Batrachochytrium dendrobatidis (Bd) in the Americas

While much research focus is paid to hypervirulent fungal lineages during emerging infectious disease outbreaks, examining enzootic pathogen isolates can be equally fruitful in delineating infection dynamics and determining pathogenesis. The fungal pathogen of amphibians, Batrachochytrium dendrobatidis (Bd), exhibits markedly different patterns of disease in natural populations, where it has caused massive amphibian declines in some regions, yet persists enzootically in others. Here we compare in vitro gene expression profiles of a panel of Bd isolates representing both the enzootic Bd-Brazil lineage, and the more recently diverged, panzootic lineage, Bd-GPL. We document significantly different lineage-specific and intralineage gene expression patterns, with Bd-Brazil upregulating genes with aspartic-type peptidase activity, and Bd-GPL upregulating CBM18 chitin-binding genes, among others. We also find pronounced intralineage variation in membrane integrity and transmembrane transport ability within our Bd-GPL isolates. Finally, we highlight unexpectedly divergent expression profiles in sympatric panzootic isolates, underscoring microgeographic functional variation in a largely clonal lineage. This variation in gene expression likely plays an important role in the relative pathogenesis and host range of Bd-Brazil and Bd-GPL isolates. Together, our results demonstrate that functional genomics approaches can provide information relevant to studies of virulence evolution within the Bd Glade12413443The authors thank Joyce Longcore for providing the Bd isolates used in this study, Miranda Gray for assistance in the laboratory, Ezra Lencer for feedback on methods, the Cornell Biotechnology Resource Center for sequencing and bioinformatics troubleshooting, and Zamudio lab members for helpful manuscript comments. This work was funded by the National Science Foundation (NSF) (grant DEB 1120249) and the Cornell Center for Vertebrate Genomic

The census of interstellar complex organic molecules in the Class I hot corino of SVS13-A

We present the first census of the interstellar Complex Organic Molecules (iCOMs) in the low-mass Class I protostar SVS13-A, obtained by analysing data from the IRAM-30m Large Project ASAI (Astrochemical Surveys At IRAM). They consist of an high-sensitivity unbiased spectral survey at the 1mm, 2mm and 3mm IRAM bands. We detected five iCOMs: acetaldehyde (CH$_3$CHO), methyl formate (HCOOCH$_3$), dimethyl ether (CH$_3$OCH$_3$), ethanol (CH$_3$CH$_2$OH) and formamide (NH$_2$CHO). In addition we searched for other iCOMs and ketene (H$_2$CCO), formic acid (HCOOH) and methoxy (CH$_3$O), whose only ketene was detected. The numerous detected lines, from 5 to 37 depending on the species, cover a large upper level energy range, between 15 and 254 K. This allowed us to carry out a rotational diagram analysis and derive rotational temperatures between 35 and 110 K, and column densities between $3\times 10^{15}$ and $1\times 10^{17}$ cm$^{-2}$ on the 0."3 size previously determined by interferometric observations of glycolaldehyde. These new observations clearly demonstrate the presence of a rich chemistry in the hot corino towards SVS13-A. The measured iCOMs abundances were compared to other Class 0 and I hot corinos, as well as comets, previously published in the literature. We find evidence that (i) SVS13-A is as chemically rich as younger Class 0 protostars, and (ii) the iCOMs relative abundances do not substantially evolve during the protostellar phase.Comment: 24 pages, MNRAS in pres

Multi-dimensionality and variability in folk classification of stingless bees (Apidae: Meliponini)

Background: Not long ago Eugene Hunn suggested using a combination of cognitive, linguistic, ecological and evolutionary theories in order to account for the dynamic character of ethnoecology in the study of folk classification systems. In this way he intended to question certain homogeneity in folk classifications models and deepen in the analysis and interpretation of variability in folk classifications. This paper studies how a rural culturally mixed population of the Atlantic Forest of Misiones (Argentina) classified honey-producing stingless bees according to the linguistic, cognitive and ecological dimensions of folk classification. We also analyze the socio-ecological meaning of binomialization in naming and the meaning of general local variability in the appointment of stingless bees. Methods: We used three different approaches: the classical approach developed by Brent Berlin which relies heavily on linguistic criteria, the approach developed by Eleonor Rosch which relies on psychological (cognitive) principles of categorization and finally we have captured the ecological dimension of folk classification in local narratives. For the second approximation, we developed ways of measuring the degree of prototypicality based on a total of 107 comparisons of the type "X is similar to Y" identified in personal narratives. Results: Various logical and grouping strategies coexist and were identified as: graded of lateral linkage, hierarchical and functional. Similarity judgments among folk taxa resulted in an implicit logic of classification graded according to taxa's prototypicality. While there is a high agreement on naming stingless bees with monomial names, a considerable number of underrepresented binomial names and lack of names were observed. Two possible explanations about reported local naming variability are presented. Conclusions: We support the multidimensionality of folk classification systems. This confirms the specificity of local classification systems but also reflects the use of grouping strategies and mechanisms commonly observed in other cultural groups, such as the use of similarity judgments between more or less prototypical organisms. Also we support the idea that alternative naming results from a process of fragmentation of knowledge or incomplete transmission of knowledge. These processes lean on the facts that culturally based knowledge, on the one hand, and biologic knowledge of nature on the other, can be acquired through different learning pathways.Fil: Zamudio, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Hilgert, Norma Ines. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Centro Cientifico Tecnologico Nordeste. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Puerto Iguazu; Argentin

Postharvest control of Rhizopus stolonifer on blackberry (Rubus fruticosus) by blackberry native crop bacteria

The potential of four native bacterial strains of blackberries cv. Brazos (Rubus fruticosus): Bacillus subtilis (BSS), Bacillus subtilis (BSL), Bacillus licheniformis (BLI) and Leifsonia aquatica (LAQ), was evaluated for the postharvest control of soft rot caused by Rhizopus stolonifer in blackberry fruits. The fruits were treated with cell suspensions (CS) and cell-free supernatants (CFE) from each bacterial strain and were infected with two strains of R. stolonifer (RSA and RSC). The severity and inhibition percentage of the disease were determined. Additionally, the inhibition by siderophores and the inhibition percentage of R. stolonifer spore germination were analyzed as possible control mechanisms. The CS of BSS inhibited RSA by 45.8%, followed by CFE of LAQ which controlled the same strain by 39.7%. The CS of BLI inhibited RSC by 37.7%, whereas the CFE of BSS and LAQ controlled it by 47.7 and 41.8%, respectively. All bacterial strains inhibited RSA and RSC by siderophores production (38.7 to 48.6 %) and the inhibition of spore germination of RSC was higher than 93% after 48 h. This work is one of the first to report R. stolonifer control by native bacteria CS and CFE, particularly LAQ in postharvested blackberry fruits. These results show the combination of mechanisms used by bacteria to control both R. stolonifer strains.The potential of four native bacterial strains of blackberries cv. Brazos (Rubus fruticosus): Bacillus subtilis (BSS), Bacillus subtilis (BSL), Bacillus licheniformis (BLI) and Leifsonia aquatica (LAQ), was evaluated for the postharvest control of soft rot caused by Rhizopus stolonifer in blackberry fruits. The fruits were treated with cell suspensions (CS) and cell-free supernatants (CFE) from each bacterial strain and were infected with two strains of R. stolonifer (RSA and RSC). The severity and inhibition percentage of the disease were determined. Additionally, the inhibition by siderophores and the inhibition percentage of R. stolonifer spore germination were analyzed as possible control mechanisms. The CS of BSS inhibited RSA by 45.8%, followed by CFE of LAQ which controlled the same strain by 39.7%. The CS of BLI inhibited RSC by 37.7%, whereas the CFE of BSS and LAQ controlled it by 47.7 and 41.8%, respectively. All bacterial strains inhibited RSA and RSC by siderophores production (38.7 to 48.6 %) and the inhibition of spore germination of RSC was higher than 93% after 48 h. This work is one of the first to report R. stolonifer control by native bacteria CS and CFE, particularly LAQ in postharvested blackberry fruits. These results show the combination of mechanisms used by bacteria to control both R. stolonifer strains