燕山山脉软枣猕猴桃的居群结构与动态研究

为探究层间藤本植物软枣猕猴桃（Actinidia arguta）在群落中的生长格局和居群动态变化，以燕山区域内的野生软枣猕猴桃为研究对象，采用样圆法分区域进行了野生软枣猕猴桃的居群结构调查，编制了特定时间生命表并绘制存活曲线。结果表明：燕山区域Ⅰ-Ⅱ径级（幼苗阶段）种群个体分别占总数量的15.39%（东段）、31.25%（中段）和30.76%（西段），总体居群结构呈"倒金字塔"型，种群表现出衰退趋势。调查区域软枣猕猴桃的高度结构基本符合连续发育特征，相对完整。燕山东段和中段的软枣猕猴桃较明显地趋近Deevey-Ⅱ型指数函数模型，燕山西段介于Deevey Ⅰ型与Ⅱ型之间，但更接近Ⅱ型；燕山山脉软枣猕猴桃居群整体呈现衰退型特征。软枣猕猴桃有较高的保护价值，但其居群数量稀少，自然更新能力较弱，种群未来的生长繁衍不容乐观，应加强关注与保护力度。     

Risk of bias tool in systematic reviews/meta-analyses of acupuncture in Chinese journals

Background

Use of a risk of bias (ROB) tool has been encouraged and advocated to reviewers writing systematic reviews (SRs) and meta-analyses (MAs). Selective outcome reporting and other sources of bias are included in the Cochrane ROB tool. It is important to know how this specific tool for assessing ROB has been applied since its release. Our objectives were to evaluate whether and to what extent the new Cochrane ROB tool has been used in Chinese journal papers of acupuncture.

Methods

We searched CBM, TCM database, CJFD, CSJD, and the Wanfang Database from inception to March 2011. Two reviewers independently selected SRs that primarily focused on acupuncture and moxibustion, from which the data was extracted and analyzed.

Results

A total of 836 SRs were identified from the search, of which, 105 were included and four are awaiting assessment. Thirty-six of the 105 SRs were published before release of the Cochrane ROB tool (up to 2009). Most used the Cochrane Handbook 4.2 or Jadad''s scale for risk or quality assessment. From 2009 to March 2011 69 SRs were identified. While “risk of bias” was reported for approximately two-thirds of SRs, only two SRs mentioned use of a “risk of bias tool” in their assessment. Only 5.8% (4/69) of reviews reported information on all six domains which are involved in the ROB tool. A risk of bias graph/summary figure was provided in 2.9% (2/69) of reviews. Most SRs gave information about sequence generation, allocation concealment, blindness, and incomplete outcome data, however, few reviews (5.8%; 4/69) described selective reporting or other potential sources of bias.

Conclusions

The Cochrane “risk of bias” tool has not been used in all SRs/MAs of acupuncture published in Chinese Journals after 2008. When the ROB tool was used, reporting of relevant information was often incomplete.     

Role of media composition in biomass and astaxanthin production of Haematococcus pluvialis under two-stage cultivation

In the present study, the effects of four different culture media on the growth, astaxanthin production and morphology of Haematococcus pluvialis LUGU were studied under two-step cultivation. The interactions between astaxanthin synthesis and secondary messengers, reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPK) were also investigated. In the first green vegetative cell stage, maximal biomass productivity (86.54 mg L⁻¹ day⁻¹) was obtained in BBM medium. In the induction stage, the highest astaxanthin content (21.5 mg g⁻¹) occurred in BG-11 medium, which was higher than in any other media. The expressions of MAPK and astaxanthin biosynthetic genes in BG-11 were higher than in any other media, whereas the ROS content was lower. Biochemical and physiological analyses suggested that the ROS, MAPK and astaxanthin biosynthetic gene expression was involved in astaxanthin biosynthesis in H. pluvialis under different culture media conditions. This study proposes a two-step cultivation strategy to efficiently produce astaxanthin using microalgae.

     

Background-dependent Wolbachia-mediated insecticide resistance in Laodelphax striatellus

Although facultative endosymbionts are now known to protect insect hosts against pathogens and parasitoids, the effects of endosymbionts on insecticide resistance are still unclear. Here we show that Wolbachia are associated with increased resistance to the commonly used insecticide, buprofezin, in the small brown planthopper (Laodelphax striatellus) in some genetic backgrounds while having no effect in other backgrounds. In three Wolbachia-infected lines from experimental buprofezin-resistant strains and one line from a buprofezin-susceptible line established from Chuxiong, Yunnan province, China, susceptibility to buprofezin increased after removal of Wolbachia. An increase in susceptibility was also evident in a Wolbachia-infected line established from a field population in Rugao, Jiangsu province. However, no increase was evident in two field populations from Nanjing and Fengxian, Jiangsu province, China. When Wolbachia was introgressed into different genetic backgrounds, followed by Wolbachia removal, the data pointed to Wolbachia effects that depend on the nuclear background as well as on the Wolbachia strain. However, there was no relationship between Wolbachia density and the component of buprofezin resistance associated with the symbiont. The results suggest that Wolbachia effects associated with chemical resistance are complex and unpredictable, but also that they can be substantial.     

基于Maxent模型的软枣猕猴桃在中国潜在适生区预测

软枣猕猴桃Actinidia arguta是猕猴桃科Actinidiaceae猕猴桃属Actinidia大型落叶藤本,据《中国植物志》记载,该物种在中国从最北的黑龙江岸至南方广西境内的五岭山地都有分布,但尚未明确其适宜分布区域。因该物种具有独特的食用和药用价值,近年来其种群数量急剧减少,现已被北京市、河北省、吉林省等列为地方性保护物种。本文利用Maxent模型对软枣猕猴桃在中国的潜在适宜分布区进行了预测并对其分布适宜性进行评价。研究结果表明:软枣猕猴桃在我国的适宜分布区总面积约为3.01×10~(6 )km~2;其高适生区主要集中在四川中部、陕西南部、湖北西部和贵州西北部等地中低山区地带,呈圆环状分布。其中软枣猕猴桃在云南、四川、陕西等省份的潜在高适生区域面积最大。利用Jackknife刀切法计算得到影响软枣猕猴桃分布的主要环境因子为最湿季度降水量(500—800 mm)、年均温(12.5—17.5℃)、最冷季度降水量(290—660 mm)和海拔(2000—2690 m),上述环境因子的累计贡献率为79.7%。建议在中高度适宜分布区进行野生软枣猕猴桃的迁地保护和人工种植,并根据其适生环境调整软枣猕猴桃的农业种植繁育规划,为软枣猕猴桃的就地、迁地保护提供了理论依据。     

Identification of a bacterium isolated from the diseased brown planthopper and determination of its insecticidal activity

The brown planthopper, Nilaparvata lugens, is one of the most harmful insect pests of rice crops in Asian countries. To find an effective biological control agent against this pest, we investigated the bacterial flora of field N. lugens collected from Jiangsu Province, China, in 2012 and tested its insecticidal activity. A novel bacterium strain, S-JS1, was isolated from N. lugens nymphs and adults and showed a high level of insecticidal activity. Based on its phenotypic, physiological and biochemical properties, and its 16S rRNA gene phylogeny, the isolate was assigned to Serratia marcescens; the name S. marcescens S-JS1 is proposed. The pathogenicity of S-JS1 against the third-instar nymphs, and the macropterous and the brachypterous adults of N. lugens were compared. The median lethal concentration (LC₅₀) values of S-JS1 against the brachypterous adult were the lowest (LC₅₀, 1.53?×?10⁸ colony forming units (cfu)/ml), followed against the macropterous adult (LC₅₀, 1.65?×?10⁹?cfu/ml) and third-instar nymphs (LC₅₀, 1.86?×?10⁹?cfu/ml) at 5 days post-infection. The median lethal time values of 8?×?10⁸?cfu/ml S. marcescens S-JS1 against the brachypterous adult, macropterous adult, and third-instar nymph were 4.5, 5.5, and 5.7 days, respectively. These results indicate that the S-JS1 isolate appears to be a promising S. marcescens strain with strong biocontrol potential against N. lugens.     

燕山山脉黄檗种群结构与动态特征

黄檗（Phellodendron amurense）为我国珍稀濒危物种，具有较高的药用价值。以燕山地区野生黄檗种群为研究对象，采用典型抽样对8个保护区内的黄檗进行全面调查，通过编制静态生命表并绘制存活曲线，分析种群年龄结构和种群变化规律，并通过种群动态量化和时间序列预测分析种群未来数量变化。结果表明：（1）黄檗种群结构总体上呈倒"J"型，但存在外部干扰时，种群结构数量变化动态指数为1.017%，表明该种群趋于稳定型；（2）静态生命表及相关曲线分析显示，黄檗种群存活数量整体上随着径级增大，个体数量逐渐下降；黄檗种群的生存期望在不同径级间存在波动，而第Ⅶ径级的生存期望最高，种群存活曲线符合Deevey-Ⅱ型，黄檗种群具有前期减少、中期稳定、后期衰退的特点；（3）时间序列预测分析表明，在未来2、4、6、8个径级之后，黄檗中老龄个体数量将逐渐增加。黄檗种群濒危的主要因素是幼苗数量少，且呈现散生分布状态，建议加强幼苗抚育工作，提高幼苗的存活率，保护和改善生境，从而促进黄檗种群的自然更新和恢复。