不同平茬方式对柽柳生长的影响

柽柳主要集中分布在额济纳河两岸,是绿洲和荒漠河岸林的主要建群种。本文采取全面平茬、团状平茬、隔株平茬3种不同方式,研究额济纳绿洲留茬30 cm的柽柳的复壮效果。结果表明:不同平茬方式下柽柳的生长状况不同。其中,全面平茬和团状平茬柽柳生长状况优于隔株平茬。林地土壤含水量在生长季呈先低后高的趋势。柽柳林下植被种类主要为骆驼刺和苦豆子,林下植被生长状况差异不明显。若平茬目的是复壮更新,综合考虑建议采用全面平茬。若所平茬的柽柳林考虑其功能以及平茬后的生长情况,建议采用团状平茬。

Fox- and raccoon-dog–associated rabies outbreaks in northern China

Dear Editor,Rabies is a generally fatal disease caused by the rabies virus(RABV),and is transmitted mainly by Carnivora and Chiroptera(Fooks A R,et al.,2014;Tao X,et al.,2013).In China,stray dogs and some wild animals(e.g.,Chinese ferret badgers,foxes,and raccoon dogs)are the principal reservoirs for RABV(Hu R L,et al.,2009).Historically,rabies in wild foxes and raccoon dogs(Nyctereutes procyonoides)was recorded in the

阿拉善盟荒漠化治理进程中的几点思考

通过对阿拉善盟荒漠化治理现状及成效的梳理,分析荒漠化治理存在的主要问题,提出在新的发展形势下阿拉善荒漠化治理的思考及启示,以期为决策者提供参考。

Control Effects of Different Agents on Tobacco Mosaic Virus Disease

[Objectives] This study was conducted to screen out suitable agents for controlling tobacco mosaic virus disease and the best control period in Zhangzhou tobacco area, providing a theoretical basis for the control of virus diseases, thereby improving the quality of flue-cured tobacco and the income of tobacco farmers. [Methods] The effects on tobacco mosaic virus disease under the interaction between different agents and different application periods were investigated. The incidence of tobacco mosaic virus disease was investigated, and its control effect was analyzed. [Results] Different agents and different application periods had different control effects on tobacco mosaic virus disease. The incidence of tobacco mosaic virus disease: At 30 and 45 d after transplanting, the incidences of A2B1 treatment were the lowest, at 0.85%, 1.71%, respectively;and at 60 d after transplanting, the incidence of A3B1 treatment was the lowest, only 10.68%. The control effect: At 30 and 45 d after transplanting, A2B1 treatment had better control effects, reaching 79.39% and 73.06%, respectively. [Conclusions] 3% hypersensitive protein sprayed at 1 d before transplanting and 7 and 15 d after transplanting achieved the best effect, followed by 10% ningnanmycin sprayed at 1 d before transplanting and 7 and 15 d after transplanting. In tobacco production, it is recommended to apply 1 000 times dilution of 3% supersensitive protein microgranules for three times(at 1 d before transplanting and 7 and 15 d after transplanting), which can effectively prevent tobacco mosaic virus disease.

Cloning, Expression, and Immunogenicity Analysis of the CpsE Protein from Group B Streptococcus Isolated from Tilapia (Oreochromis Niloticus)

Group B Streptococcus (GBS) is a major cause of serious bacterial infection in numerous animal species. The production of capsular polysaccharide(CPs) is vital to GBS to evade host immunity. One of the genes that required for production of CPs, cpsE, has been determined to be well conserved in capsule gene cluster (cps).This study cloned the cpsE gene from Tilapia of GBS clinical isolate (serotype Ia) and expressed this gene with aid of pET-32a(+) in Escherichia coli BL21(DE3) competent cells to obtain high levels of the recombinant protein for further study about CpsE in fish and examination of its immunogenicity. The optimization of induction conditions (IPTG concentration, temperature and time) in E.coli was accomplished and let us to perform the recombinant protein induction at 37℃ for 3h,with 0.2mM IPTG in Luria Bertani (LB) medium. At the optimal conditions, recombinant protein was expressed in an insoluble form (inclusion bodies) and accounted for approximately 23% of the total protein. Purification by affinity chromatography yielded about 480mg fusion protein per liter culture.

阿拉善盟生态林管护问题与对策

通过对阿拉善盟多年来营造林情况的梳理,分析当前阿拉善盟营造林后期管护中存在的问题,提出相应的对策与建议,以期为决策者提供参考。