植被变化与水沙响应关系研究——以延河流域为例

以延河流域为研究对象,利用TM影像和降雨、径流泥沙数据,基于统计学和RS/GIS技术方法,分析了流域植被与水沙之间的响应关系及自然恢复植被的减水减沙效益.结果表明:2003-2005年与80年代相比,降雨增加导致径流量、输沙量增加8.1％、47.5％;人类活动导致径流量、输沙量减少23.4％、55.6％;人工林草植被减少径流量、泥沙量为0.228亿m3、543.478万t,自然恢复植被减少径流量、泥沙量为0.121亿m3、152.970万t;人工林草植被的减水、减沙效益占人类活动贡献的46.94％、30.64％,而自然恢复植被的减水、减沙效益占24.97％、8.62％.植被在水土保持中的作用日益突出,自然恢复植被减水减沙比重增大,“封育”措施在流域治理中具有重要意义.     

A comprehensive approach for assessing the economic contribution of forage and livestock improvement options to smallholder farming enterprises

The importance of livestock production activities to improving the livelihoods of smallholder farming households and the efficiency of their underlying farming systems is increasingly recognized.A rapid increase in livestock numbers, especially beef cattle, and special purpose forages is being promoted for smallholder farms which have traditionally undertaken subsistence cropping activities or simple livestock rearing activities using low quality feedstuffs.Because limited plantings of specialized forages combined with a poor knowledge of animal nutrition are a challenge to establishing sustainable livestock enterprises, much public policy and research is now being focused on the use of new forages and improved feeding practices.A number of economic studies have suggested that specialized forage growing and livestock feeding activities can make a positive contribution to smallholder welfare.The studies have typically compared the total level of farm or household income with and without livestock activities.Little attention is given to how much the new forage or livestock activities actually contribute to or draw resources from other farm activities to assess their real economic contribution to the enterprise, and the availability of simple tools to assist in making such assessments are limited.This paper describes a simple modelling approach that was developed for an Australian Centre for International Agricultural Research(ACIAR)-supported project to explore the real as opposed to apparent economic impact of integrating improved forages and livestock within smallholder farming systems in the Red Soils region of south-central China.Application of the model is demonstrated using a simple case study of a smallholder enterprise that plans to introduce a new beef cattle rearing activity to its existing farm activity mix.The case study highlights the importance of explicitly valuing transfers of resources between different farm activities to gauge the real contribution of those activities to economic returns.     

The effects of high temperature level on square Bt protein concen-tration of Bt cotton

Higher boll worm survival rates were detected after high temperature presented during square period in Bt cotton. The objective of this study was to investigate the effects of high temperature level on the Bt efficacy of two different types of Bt cotton cultivars at squaring stage. During the 2011 to 2013 cotton growth seasons, high temperature treatments ranged from 34 to 44°C in climate chambers, and field experiments under high temperature weather with various temperature levels were conducted to investigate the effects of the high temperature level on square Bt protein concentration and nitrogen metabolism. The climate chamber experiments showed that the square insecticidal protein contents reduced after 24 h elevated temperature treatments for both cultivars, whereas significant declines of the square insecticidal protein contents were detected at temperature 38°C, and only slightly numerical reductions were observed when temperature below 38°C. Similar high temperature responses were also observed at the two field experimental sites in 2013. Correspondingly, high temperature below 38°C seems have little effect on the square amino acid concentrations, soluble protein contents, glutamic-pyruvic transaminase(GPT) and glutamic-oxalacetic transaminase(GOT) activities as well as protease and peptidase activities; however, when the temperature was above 38°C, reduced soluble protein contents, enhanced amino acid concentrations, decreased GPT and GOT activities, bolstered protease and peptidase activities in square were detected. In general, the higher the temperature is(38°C), the larger the changes for the above compound contents and key enzymes activities of the square protein cycle. The findings indicated that the unstable insect resistance of the square was related to high temperature level during square stage.     

Applying a salinity response function and zoning saline land for three fi eld crops: a case study in the Hetao Irrigation District,Inner Mongolia,China

Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat(Triticum aestinum L.), maize(Zea mays L.) and sunflower(Helianthus annuus L.), growing in 76 farm fields are evaluated with modified discount function. Salinity ecological zones appropriate for these local crops are characterized and a case study is presented for crop salinity ecological zoning. The results show that the yield reductions of wheat, maize and sunflower when grown in saline soils are attributed primarily to a reduction in spikelet number, 1 000-grain weight and seed number per head, respectively. Sunflower is the most tolerant crop among the three which had a salinity tolerance index(ST-index) of 12.24, followed by spring maize and spring wheat with ST-Indices of 9.00 and 7.43, respectively. According to the crop salinity tolerance results, the arable land in the Heping Village of this district was subdivided into four salinity ecological zones: the most suitable, suitable, sub-suitable and unsuitable zones. The area proportion of the most suitable zone for wheat, maize and sunflower within the Heping Village was 27.5, 46.5 and 77.5%, respectively. Most of the most suitable zone occurred in the western part of the village. The results of this study provide the scientific basis for optimizing the local major crop distribution and improving cultural practices management in Hetao Irrigation District.     

犬瘟热病毒感染机制及其诊断方法研究进展

本综述介绍了犬瘟热病毒的6种结构蛋白N、P、L、F、H和M蛋白在病毒入侵宿主和宿主细胞内繁殖的功能;简要描述了犬瘟热病毒入侵动物机体感染传播的机制,其中细胞受体SLAM和PVRL4解释病毒的趋向性;介绍了临床诊断、试验动物法、血清学方法和核酸诊断等鉴别诊断犬瘟热的方法及其优缺点.通过系统了解犬瘟热病毒的感染途径及其诊断方法,有助于发现控制犬瘟热病毒传播的新方法.     

普通油茶无性系岑软3号嫁接亲和性研究

以普通油茶本砧嫁接为对照,研究博白大果油茶、广宁红花油茶、香花油茶、陆川油茶与普通油茶优良无性系岑软3号苗期的嫁接亲和性。结果表明:香花油茶作为砧木嫁接岑软3号的成活率及存活率分别达到了91.67%和98.55%,抽梢以及嫁接苗的生长与以普通油茶作为砧木均没有显著性差异,参试的4个物种中香花油茶与岑软3号的嫁接亲和力最好;其次是陆川油茶,嫁接成活率和存活率分别达到了93.67%和95.00%,但嫁接苗生长1年后叶片N、P、K含量显著低于对照;广宁红花油茶在嫁接过程中表现出了一定的不亲和性,嫁接成活率仅为72.00%,且后期生长受到抑制;而博白大果油茶嫁接成活1 a后的存活率仅为24.49%,生长受阻,嫁接后期表现出了明显的不亲和性。     

二型花柱植物红蓼的繁殖生物学研究

本研究发现了红蓼的异型花柱现象,红蓼野外居群存在长柱型花和短柱型花。研究表明长/短柱花型具有精确的交互式异位特征,其花大小,柱头形态,乳突大小,花粉粒数目、大小都表现出两型性(P<0.01)。与长柱型花相比,短柱型花较大,有短且排列紧密的柱头乳突细胞,花药产生较少且大的花粉。长/短柱型花花瓣长度无显著差异(P>0.01)。扫描电镜显示两型花的花粉均具有散孔,孔近似圆形,边缘形状不规则。野外调查发现蓟马、蚂蚁、食蚜蝇为主要访花者。人工授粉,红蓼长/短柱型花自交、型内异交以及型间异交花粉管均萌发,0.5 h花粉管已萌发至子房,只有部分花粉管能萌发至子房且沿花柱壁及子房壁生长,说明其受精方式为合点受精。长/短柱型花型内异交座果率分别为14.00%和13.33%,自交座果率分别为4.62%和2.86%,型间异交的座果率分别为43.33%和44.61%,表明红蓼长/短柱型花自交表现出一定的亲和性,但座果率低,仍以异交为主。     

东方山羊豆GoGID基因表达载体构建及紫花苜蓿转化

根据已经克隆得到的东方山羊豆赤霉素受体(GoGID)基因,扩增编码区cDNA.以pBI121为基础载体,采用酶切连接法,构建植物超表达载体pBI121-GoGID.酶切鉴定表明:目的基因已经正确插入载体中,超表达载体构建成功.采用CaCl₂冻融法将重组载体转入农杆菌菌株中.以叶片为外植体,采用农杆菌介导的愈伤组织培养法,转化紫花苜蓿(Medicage sativa),得到抗性苗.对载体携带的nptⅡ基因、GUS基因进行PCR检测均成阳性,表明目的基因已成功导入紫花苜蓿基因组中.同时对转基因植株进行Southern-blot及RT-PCR检测,并均得到目的条带.本研究为进一步分析GoGID基因对紫花苜蓿生物量影响奠定了基础.     

南昌市3个城中湖泊夏季轮虫和甲壳类群落特征及水质评价

为探究城市湖泊浮游动物群落结构特征和分布与水环境因子之间的关系,并评价南昌市典型城市湖泊夏季水质状况,运用多维尺度分析（MDS）和典范对应分析（CCA）方法,对南昌3个城市湖泊———东湖、青山湖、月亮湖的轮虫和甲壳类浮游动物群落进行了研究,分析了浮游动物的多样性指数。结果表明,轮虫是夏季城市湖泊中浮游动物的优势类群,优势度（Y）大于0．02的浮游动物分别为剪形臂尾轮虫（Brachionus forficula）、裂足臂尾轮虫（Brachionus diversicornis）、萼花臂尾轮虫（Brachionus calyciflorus）、桡足类无节幼体（Copepoda nauplii）和卜氏晶囊轮虫（Asplanchna brightwelli）;3个湖泊之间浮游动物的群落结构差异显著（P ＜0．05）,明显划分为东湖群落、青山湖群落和月亮湖群落。叶绿素 a 浓度、浊度和溶氧是浮游动物分布的显著影响因子（P ＜0．05）。多样性指数评价显示,东湖为清洁型水体,青山湖为清洁－中污型水体,月亮湖为轻污－中污型水体。综合评价表明,东湖和青山湖水体为寡营养水平,月亮湖为中富营养水平。     

利用iTRAQ蛋白质组技术筛选与鸡喙畸形相关的候选蛋白

【目的】中国地方鸡种如北京油鸡、清远麻鸡存在喙畸形现象,表现为上下喙咬合不全,呈交叉状。严重影响鸡饮水和采食,从而影响个体发育和生产性能的发挥,造成一定经济损失。笔者根据喙畸形个体的系谱记录,发现喙畸形的形成受到遗传因素的影响,但具体机制尚不明确。蛋白是行使各种生物学功能的最终形式之一,喙畸形个体的发生可能是由于核心蛋白或者相关调控蛋白代谢异常造成的。利用同位素标记相对和绝对定量（isobaric tags for relative and absolute quantitation,iTRAQ）技术以及生物信息学分析方法,筛选鸡畸形喙与正常喙中差异表达的蛋白,作为喙畸形相关的重要候选蛋白,为进一步研究北京油鸡喙畸形的遗传机制奠定基础。【方法】挑选3只120日龄喙畸形的公鸡作为试验组,编号为W1、W2、W3,同时,挑选与试验组个体为同胞关系（全同胞或半同胞）的喙正常公鸡作为对照组,编号为Z1、Z2、Z3。将喙畸形与其同胞正常个体作为一个比对组,iTRAQ试验具体包含3个比对组,即W1 vs Z1,W2 vs Z2,W3 vs Z3。屠宰个体后,剔除喙组织周围肌肉和筋膜,分离得到喙上颌骨和下颌骨,提取总蛋白样品,应用6个 iTRAQ标签标记各蛋白样品,经过色谱层析预分离,联合液相串联质谱分析,采用Mascot 2.3.02软件对蛋白进行鉴定和定量分析。试验组（W）与其同胞对照组(Z)样本比较（W1 vs Z1,W2 vs Z2,W3 vs Z3）,选择肽段数≥2,表达差异值＞1.2（上调）或＜0.83（下调）,且P＜0.05的蛋白作为差异表达蛋白。【结果】利用iTRAQ技术一共在喙组织中鉴定到3 372个蛋白,鉴定到的特异性肽段有12 769个。其中原鸡蛋白1 869个,分子质量主要分布在10-100 kD之间。3个比对组共鉴定出159个表达量有显著差异的蛋白质,其中包含70个表达上调的蛋白,89个表达下调的蛋白。统计各比对组蛋白表达差异值发现,表达量差异较大的上调蛋白质有LPL、MLC-2、CO9A1、MATN3、HSP90B1等,表达量差异较大的下调蛋白质有MBP、RLA1、PRVM、HAPLN1等。结合已经报道的这些蛋白的生物学功能,其中CO9A1、MATN3、HAPLN1与软骨合成和软骨骨化相关,CO9A1是带状软骨纤维的组成物质,MATN家族是非胶原性细胞外基质蛋白家族,HAPLN1是软骨细胞外基质的重要组成成分;PRVM是细胞内钙离子结合蛋白,参与调控Ca2+离子信号通路;LPL是多功能酶,主要在脂质代谢和转运过程中起作用,参与调控PPAR信号通路。初步筛选出CO9A1、MATN3、HAPLN1、PRVM、LPL作为与鸡喙畸形相关的候选蛋白。【结论】差异表达蛋白的发现为鸡喙畸形形态的发生提供蛋白质水平上的理论依据。