生防蜡样芽胞杆菌Bacillus cereus 905基因组测序及分析     

丁海霞  牛犇  范海燕  李燕  王琦 《中国农业大学学报》2016,21(12):49-57

为深入研究蜡样芽胞杆菌905(Bacillus cereus 905)的促生防病机制以及为进一步优化该菌株提供遗传学信息,采用454焦磷酸测序技术对B.cereus 905基因组进行了测序,并使用相关软件对测序数据进行了基因组拼接、基因功能预测与注释、基因本体分析(GO)、直系同源基因簇(COG)聚类分析以及共线性分析。结果表明:B.cereus 905基因组草图序列大小约为5.39 Mb,GC含量35.05%,由127个片段重叠群组成;该序列已提交GenBank数据库,登录号为LSTW00000000;分析发现菌株905的基因组与其他蜡样芽胞杆菌的基因组有显著的共线性关系;菌株905基因组中存在相当数量的与促生防病功能相关的基因。本研究通过对B.cereus 905基因组的测序为该菌株的优化提供了序列信息。  相似文献   

Upgrading of UV Protection Properties of Several Textile Fabrics by Their Dyeing with Grape Pomace Colorants     

Noureddine Baaka  Manel Ben Ticha  Wafa Haddar  Maria Teresa Pessoa Amorim  Mohamed Farouk Mhenni 《Fibers and Polymers》2018,19(2):307-312

The desire to offer clothes protective properties against the harmful UV rays continues to attract the interest of researchers. Several works have been elaborated in this topic and have proved that the clothes do not protect sufficiently against the solar ultraviolet radiation. Their protectiveness depends on the fiber type, the fabric composition, the fabric construction and the dyeing method. This research presents a novel approach which target the improvement of the textile protective properties against UV rays by their dyeing with grape pomace aqueous extract. These properties were tested in combination with several fabrics (natural and synthetic) and mordants (potassium alum and ferrous sulphate). Through this study, it has been shown that the UV-protective properties of the several dyed fibers were upgraded after dyeing with the grape pomace extract, and is intensely relying on the types of fibers and mordants.  相似文献   

Characterization of tuber blight‐suppressive soils from four provinces of the Ecuadorean Andes          下载免费PDF全文

G. Orquera‐Tornakian  C. I. Díaz  D. C. Mogrovejo  D. J. Villamarín  F. Jarrín  L. K. Ponce  R. Oliva  J. Gia  G. A. Forbes  J. Andrade‐Piedra  F. J. Flores  C. D. Garzon  J. Molineros  A. Koch  M. S. Benítez 《Plant pathology》2018,67(7):1562-1573

Late blight, caused by the oomycete Phytophthora infestans, is a threat to potato‐cropping systems worldwide. In the Ecuadorian Andes, despite a high late blight incidence in foliage, tuber blight is rare. In this work, the hypothesis that Ecuadorian Andean soils are naturally suppressive to P. infestans tuber infection was evaluated. Soils from four potato‐growing regions were assessed for disease suppressiveness by determining the effects of soil heat treatment on P. infestans sporangia and their ability to infect potato slices after 1, 8, 15 and 30 days of exposure to soils. Tuber infection after inoculation with P. infestans‐infested soils was consistently lower during the evaluation period compared with heat‐treated soils. Fresh, untreated soils affected germination and viability of P. infestans sporangia in a site‐dependent manner. In addition, the effect of heat treatment on soil bacterial communities was assessed through terminal restriction fragment length polymorphism analysis of the 16S rDNA gene region. Heat treatment disrupted bacterial community composition, and a subset of terminal restriction fragments (TRF) was either positively or negatively correlated with tuber infection. Bacterial TRF negatively correlated with tuber infection corresponded in fragment size to taxa with known ability to inhibit pathogens and promote plant growth. Finally, bacterial isolates obtained from untreated soils, which inhibited P. infestans growth in vitro, represented 22–47% of isolates recovered, and matched classes predicted by the TRFs. This work represents a first step in understanding the mechanisms behind the low incidence of tuber blight in Andean potato‐cropping systems.  相似文献   

Design,synthesis, fungicidal property and QSAR studies of novel β‐carbolines containing urea,benzoylthiourea and benzoylurea for the control of rice sheath blight          下载免费PDF全文

Zhi‐Jun Zhang  Yong Zeng  Zhi‐Yan Jiang  Ben‐Shui Shu  Veeran Sethuraman  Guo‐Hua Zhong 《Pest management science》2018,74(7):1736-1746

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Nutrient Leaching from Soil Amended with Manure and Compost from Cattle Fed Diets Containing Wheat Dried Distillers’ Grains with Solubles     

Ping Li  Man Lang  Chunli Li  Ben W. Thomas  Xiying Hao 《Water, air, and soil pollution》2016,227(10):393

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Root-zone temperature affects the phytoextraction of iron in contaminated soil     

Mourad Baghour  Kaoutar Ben Chekroun  Juan Manuel Ruiz Sáez  Luis Romero 《Journal of plant nutrition》2016,39(1):51-58

The effect of root temperatures on the uptake and content of iron (Fe) in different organs of potato plants was studied. Four different plastic covers were used (T1: transparent polyethylene; T2: white polyethylene; T3: white and black coextruded polyethylene), using plants without plastic covers as control (T0). The results of this study indicate that in treatments with the highest root temperature (T2 and T3), chelate-reductase activity significantly increased, that could enhance the uptake and subsequent accumulation of Fe in the different organs analyzed of the potato plant. In addition, the roots and particularly the tubers proved to be the main organs of Fe bioaccumulation in treatments T0, T2, T3, and T4. On the contrary, in the T1 treatment, the bioaccumulation of Fe was detected in the shoot (stems and leaves). Finally, the foliar bioindicators of Fe analyzed, chl a and b, carotenes, peroxidase activity and catalase activity reflected the foliar status of Fe.  相似文献   

Bursaphelenchus tusciae in Tunisia associated with Hylurgus ligniperda          下载免费PDF全文

M. Mejri  L. Fonseca  J. M. S. Cardoso  M. L. Ben Jamâa  I. Abrantes 《Forest Pathology》2016,46(6):663-665

Bursaphelenchus tusciae is reported for the first time in Tunisia and North Africa, associated with the insect Hylurgus ligniperda Fabricius (Coleoptera: Curculionidae: Scolytinae). Nematode identification was based on restriction fragment length polymorphism analysis and sequencing of the internal transcribed spacer (ITS) regions of ribosomal DNA. Phylogenetic analysis revealed that Tunisian B. tusciae clusters together with two other B. tusciae isolates forming a separate group close to B. hildegardae and B. eggersi. As H. ligniperda is among maritime pine scolytids pests in Tunisia and is widely distributed in North Africa, this study is an important contribution to the knowledge of Bursaphelenchus species associated with bark beetles of pine forests in Tunisia and North Africa.  相似文献   

Allometric growth patterns and development in larvae and juveniles of thick‐lipped grey mullet Chelon labrosus reared in mesocosm conditions     

Ines Ben Khemis  Enric Gisbert  Carles Alcaraz  Dora Zouiten  Raouf Besbes  Amina Zouiten  Ahmed Slaheddine Masmoudi  Chantal Cahu 《Aquaculture Research》2013,44(12):1872-1888

Allometric growth and ontogeny were studied in thick‐lipped grey mullet Chelon labrosus reared in mesocosms from 1 to 71 day post hatching (dph). Multivariate allometric analysis of morphometric growth distinguished three distinct developmental stanzas separated by two morphometric metamorphosis lengths (L_m1 = 4.46 ± 0.06 mm; L_m2 = 28.56 ± 1.04 mm). Body mass growth also showed three distinct episodes separated by two inflections, correlated with morpho‐functional changes. First episode concerned pre‐flexion larvae and ended around 4.5 mm‐L_T (14‐dph), coinciding with estimated L_m1. It was distinguished by reduced growth, but intense morphogenesis and differentiation processes. Organogenesis and allometric changes indicated that development priorities concerned feeding efficiency, by improving detection ability (sensory system development), ingestion capacity (head growth) and assimilation performance (digestive system differentiation), together with respiration efficiency (gill development). Second episode concerned post‐flexion larvae and, ended around 8.6 mm‐L_T (25‐dph). It was distinguished by fast growth of trunk and tail, acquisition of adult axial muscle distribution and completion of gill filament development, improving locomotion and oxygenation performances. It corresponded to transition towards metamorphosing stage as indicated by later isometric growth, musculature maturation and acquisition of juvenile phenotype. Metamorphosis seemed to end at L_m2, suggesting to avoid zootechnic handling before this size.  相似文献   

Total substitution of fish oil by vegetable oils in Senegalese sole (Solea senegalensis) diets: effects on fish performance, biochemical composition, and expression of some glucocorticoid receptor-related genes     

Vanessa Benítez-Dorta  María J. Caballero  Marisol Izquierdo  Manuel Manchado  Carlos Infante  María J. Zamorano  Daniel Montero 《Fish physiology and biochemistry》2013,39(2):335-349

To study the substitution of fish oil by vegetable oils in fish diets, juveniles Senegalese sole (Solea senegalensis) were fed diets (56 % crude protein, 12 % crude lipid) containing either linseed (100LO) or soybean (100SO) oils in comparison with a 100 % fish oil-based diet (100FO) for 90 days. Samples of muscle, liver, and intestine were collected for biochemical analysis and for glucocorticoid receptor-related genes, including GR1 and GR2, and the associated heat shock proteins HSP70, HSP90AA, and HSP90AB. Besides, basal levels of plasma cortisol were also determined. After the feeding period, a stress test, consisting on 5 min of net chasing, was applied to a selected population of each dietary group. Total replacement of fish oil by vegetable oils did not induced changes in fish growth and performance, but affected fatty acid profile of muscle, liver, and intestine, reflecting those tissues the characteristic fatty acids of each type of dietary oil. A tendency to conserve the ARA/EPA ratio could be observed in the different tissues, despite of the level of these fatty acids in diet. Chasing stress induced an increase of muscle GR1 and a reduction in intestinal GR2 relative expressions at any of the experimental diets assayed. In liver, chasing stress induced an increase in both GR1 and GR2 gene expression in fish fed fish oil diets. Similarly, chasing stress induced an increase of muscle HSP70 and decrease of HSP90AB in liver at any of the experimental diet assayed. Besides, vegetable oils decreased the expression of HSP70 in intestine, being the relative expression of liver HSP90AA increased by the inclusion of linseed oil in the diet, at any of the experimental conditions assayed.  相似文献   

Choosing and rejecting cattle and sheep: changing discourses and practices of (de)selection in pedigree livestock breeding     

Lewis Holloway  Carol Morris  Ben Gilna  David Gibbs 《Agriculture and Human Values》2011,28(4):533-547

This paper examines the discourses and practices of pedigree livestock breeding, focusing on beef cattle and sheep in the UK, concentrating on an under-examined aspect of this—the deselection and rejection of some animals from future breeding populations. In the context of exploring how animals are valued and represented in different ways in relation to particular agricultural knowledge-practices, it focuses on deselecting particular animals from breeding populations, drawing attention to shifts in such knowledge-practices related to the emergence of “genetic” techniques in livestock breeding which are arguably displacing “traditional” visual and experiential knowledge’s of livestock animals. The paper situates this discussion in the analytical framework provided by Foucault’s conception of “biopower,” exploring how interventions in livestock populations aimed at the fostering of domestic animal life are necessarily also associated with the imperative that certain animals must die and not contribute to the future reproduction of their breed. The “geneticization” of livestock breeding produces new articulations of this process associated with different understandings of animal life and the possibilities of different modes of intervention in livestock populations. Genetic techniques increasingly quantify and rationalize processes of selection and deselection, and affect how animals are perceived and valued both as groups and as individuals. The paper concludes by emphasizing that the valuation of livestock animals is contested, and that the entanglement of “traditional” and “genetic” modes of valuation means that there are multiple layers of valuation and (de)selection involved in breeding knowledge-practices.  相似文献