江西毛竹林土壤理化性质与养分吸附特性

为了了解江西省毛竹林土壤养分状况,采用常规和土壤养分系统研究法,分析了不同分布区毛竹林土壤理化性质和养分吸附特性。结果表明：不同分布区毛竹林土壤理化性质不同,但只有容重差异显著。容重以于都最大,崇义较小,土壤孔隙状况与之相反,持水性能变化规律不明显。不同分布区Fe、 Mn、 S和B较丰富, N、 P、 K低于临界值;崇义和兴国土壤Ca和Mg、于都土壤Zn、铜鼓土壤Ca、 Mg、 Zn和Cu均低于临界值。不同分布区间,于都土壤P、 K和Cu吸附率最高, S、 Mn、 Zn和B吸附率分别以铜鼓、贵溪、兴国和崇义最高;兴国土壤K、 S、 Cu和Mn吸附率最低,铜鼓土壤P和Zn吸附率最低, B吸附率以贵溪最低。土壤理化性质对不同养分元素的影响不同;容重与土壤孔隙状况、容重与持水性能、有机质和pH与养分吸附率的相关性呈相反的趋势;养分元素吸附率与该元素养分含量呈不同的相关关系,有正相关( Mn和Zn)、负相关( S和Cu)和相关性不明显( P、 K和B)。不同分布区养分元素含量的缺乏和丰富状况不同,在指导实际生产中,应充分考虑土壤养分状况和土壤对养分元素的吸附作用,采取合理的养分管理措施,从而达到环境友好、可持续的毛竹林经营。     

纳塔生产中污染真菌的分离与控制

纳塔生产中真菌污染现象最普遍、危害最严重。从纳塔工厂的受污染发酵液、原料椰子水及环境中分离到58株酵母、17株霉菌。研究显示,产膜醭酵母,如假丝酵母(Candidaspp.)、毕赤酵母(Pichiaspp.)是引起污染的主要真菌,它们主要来源于大量带菌的原料椰子水,由于椰子水的不恰当处理而散布到环境中。向发酵液中添加2~3g/L脱氢醋酸钠或1.5~2g/L尼泊金丁酯,可以较好地抑制产膜醭酵母而不影响木醋杆菌的生长和纳塔的合成。      

Aspects of emergency vaccination against foot-and-mouth disease

Emergency vaccination is one of several measures which may be deployed to control outbreaks of foot-and-mouth disease. It can be a valuable adjunct to the application of the essential zoosanitary controls which must include rapid diagnosis, tracing, movement control and disinfection and which may also include slaughter of infected and in-contact animals and their safe disposal. Criteria which determine the successful application of emergency vaccination include access to vaccine(s) that (i) contain virus strain(s) of sufficient antigenic relatedness to the outbreak strain(s) (ii) are of the required type of vaccine formulation (iii) have acceptable innocuity and potency (iv) have appropriate availability, including quantity and immediacy of supply and (v) meet considerations of cost. Contingency planning should include provision for emergency vaccination and must address the complex decisions of not only when, where, and how to apply vaccine but also its economic consequences. Computer modelling may be a useful aid to cost benefit and decision support systems in this context. Planning must be detailed and regularly reviewed and should ensure, (i) that the legal and financial aspects are catered for (ii) that any contractual supply agreements are in place (iii) that information is collected and its currency maintained on the species, numbers and whereabouts of susceptible livestock (iv) that vaccination teams are formed and trained (v) that the vaccine cold chain is established and maintained (vi) that supplies of vaccination equipment are held in readiness and (vii) that briefing materials are available to inform the various stakeholders on relevant aspects of emergency vaccination. Knowledge concerning the characteristics and performance of emergency vaccines is summarised and areas identified for further research.     

Prevalence of Ehrlichia canis infection in thrombocytopenic dogs from Rio de Janeiro, Brazil

BACKGROUND: Infection with Ehrlichia canis causes a highly variable, multisystemic disease in dogs. Nevertheless, many clinicians in Rio de Janeiro, Brazil, use the presence of only thrombocytopenia to make a presumptive diagnosis of E canis infection. OBJECTIVE: The objective of this study was to determine the prevalence of E canis in thrombocytopenic dogs from Rio de Janeiro, Brazil, using polymerase chain reaction (PCR). METHODS: Following DNA extraction of whole blood samples from 226 dogs, PCR assays were done using primers for rickettsial DNA (including Ehrlichia spp, Anaplasma platys and A phagocytophilum) and using E canis-specific primers (16S rRNA gene). Dogs were grouped as thrombocytopenic and nonthrombocytopenic based on platelet counts. The null hypothesis that there was no difference in the prevalence of E canis in these groups was rejected at P<.05. RESULTS: Thirty-six (32.1%) of the thrombocytopenic dogs and 4 (3.5%) of the nonthrombocytopenic dogs were positive for rickettsial gene sequences (P<.0001). Further, 30 (26.8%) of thrombocytopenic dogs and 4 (3.5%) nonthrombocytopenic dogs were positive for E canis-specific gene sequences (P<.0001). CONCLUSIONS: Although the prevalence of E canis infection was higher in thrombocytopenic dogs, less than one third of these dogs had demonstrable E canis infection. Thus, thrombocytopenia is not specific for the detection of E canis infection and should not be used solely to establish a diagnosis of canine ehrlichiosis, even in a geographic area with relatively high disease prevalence.     

毛竹竹材几个热力学特性参数的测试与分析

采用闪光法和比较法及直线法分别测量了毛竹竹材沿垂直竹纤维方向的几个热力学特性参数:热扩散率α、比热Cp及竹材密度ρ, 并根据公式λ= 418.68 α Cp ρ得出其另一个重要的热力学特性参数--导热系数λ.结果表明:竹材的热扩散率α与竹材生长的方向和高度的关系不大;导热系数λ、热扩散率α、比热均Cp在温度为70℃左右时具有最大值.这一结果对竹材的热处理加工具有一定的指导意义.     

Sea cucumber fisheries: global analysis of stocks,management measures and drivers of overfishing

Worldwide, most sea cucumber fisheries are ineffectively managed, leading to declining stocks and potentially eroding the resilience of fisheries. We analyse trends in catches, fishery status, fishing participation and regulatory measures among 77 sea cucumber fisheries through data from recent fishery reports and fishery managers. Critical gaps in fisheries biology knowledge of even commonly targeted species undermine the expected success of management strategies. Most tropical fisheries are small‐scale, older and typified by numerous (>8) species, whereas temperate fisheries are often emerging, mono‐specific and industrialized. Fisher participation data indicated about 3 million sea cucumber fishers worldwide. Fisher participation rates were significantly related to the average annual yield. permanova analysis showed that over‐exploited and depleted fisheries employed different sets of measures than fisheries with healthier stocks, and a non‐metric multidimensional scaling ordination illustrated that a broad set of regulatory measures typified sustainable fisheries. SIMPER and regression tree analyses identified that the dissimilarity was most related to enforcement capacity, number of species harvested, fleet (vessel) controls, limited entry controls and rotational closures. The national Human Development Index was significantly lower in countries with over‐exploited and depleted fisheries. Where possible, managers should limit the number of fishers and vessel size and establish short lists of permissible commercial species in multispecies fisheries. Our findings emphasize an imperative to support the enforcement capacity in low‐income countries, in which risk of biodiversity loss is exceptionally high. Solutions for greater resilience of sea cucumber stocks must be embedded within those for poverty reduction and alternative livelihood options.     

Cloning and Characterization of Gene cab-PhE4 in Phyllostachys edulis

A fragment with about 798 bp of cab gene was amplified from the first strand of Moso （Phyllostachys edulis） cDNA through RT-PCR method, named as cab-PhE4 （cab gene 4 from Ph. edulis）. The cab-PhE4 （GenBank accession number： EF405878） gene encodes 265 amino acid. The bioinformatics analysis indicated that the protein encoded by cab-PhE4 has a chlorophyll a/b-binding domain （64th- 232nd position）, a protein kinase C phosphorylation site （33rd-35th position）, a N-myristoylation site （169th-174th position）, and an involucrin repeat （207th-216th position）. The amino acid sequence of cab- PhE4 showed high similarity with the cab genes of Zea mays, Triticum aestivum, Musa acuminata, Panax ginseng and Oryza sativa, more than 90%, respectively.     

Effect of auxins on axillary and de novo shoot regeneration from in vitro shoot cultures derived from forced epicormic buds of teak (Tectona grandis L.)

In this presentation,we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term,from cultures of Tectona grandis L.Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenic shoot-culture establishment.Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N 6-benzyleadenine (BA,8.8 μmol L-1) and indole-3-butyric acid (IBA,2 μmol L-1) for 24 months.Vigorously growing shoot tips (2 3 cm long) were inoculated on the MS basal medium supplemented with different concentrations (0,1,2,4,6,8 or 10 μmol L-1) of either IBA or α-naphthaleneacetic acid (NAA) for rooting.Axillary and de novo shoots were developed from axillary and cut basal ends of shoots,respectively.Shoots growing on auxins were further sub-cultured (every 15 days) and maintained for 45 days.The greatest number of de novo (5.06) as well as axillary shoots (2.85) was observed on the MS medium supplemented with 10 μmol L-1 NAA or 8 μmol L-1 IBA,respectively,after 45 days.The combinations of both IBA (μmol L-1) + NAA (μmol L-1) were tested at different concentrations (4 + 4,6 + 6,8 + 8) supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots.Rooting from non-decapitated de novo shoots was highest (93.33%) with a mean number of roots of 4.61 on this medium,supplemented with 6 μmol L-1 IBA + 6 μmol L-1 NAA,after 36 days of initial culture.Individual auxin,however,was not effective for root induction.Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.     

天全县毛竹实生林速生丰产配套技术研究

四川省天全县从2001年至2003年在17个乡镇发展毛竹实生苗造林14 466.67 hm2,至2006年郁闭成林,本文研究了毛竹成林到成材的前10 a生长主导因素。结果表明:毛竹造林用苗,宜用整窝实生苗。实生苗造林前5a主要是补植抚育保成活,最主要的措施是砍灌、除草、亮窝正苗。后5 a是成材的关键时期,主要措施是控制立竹度,保持4 500株·hm-2～10 500株·hm-2都可以,超过10 500株影响成材。施肥效应对成材影响不明显,毛竹苗从栽植到第8个年头,几乎都可以不施肥,以后施肥以P、K为主,每hm2在1500 kg以内即可;将四川毛竹造林海拨向上推进了200 m达到1 400 m。     

四种de novo组装软件对柞蚕微孢子虫全基因组组装结果的比较

柞蚕是一类以柞树叶为食料的经济类吐丝结茧昆虫,柞蚕微孢子是寄生在柞蚕体内的一种微孢子虫,是柞蚕微粒子病的病原,其主要通过食下传染或者母体传染来感染柞蚕。目前在分子水平上对柞蚕微孢子虫的研究还很少,本研究通过比较分析四种常见的de novo组装软件对柞蚕微孢子虫全基因组的组装,结果显示不同的软件组装的结果相差甚远,由此表明由于柞蚕基因组本身结构的特殊性及组装软件的针对性,导致了组装质量的差异性。本研究对于今后昆虫微孢子虫基因组的组装软件的选择优化提供了重要的参考。