粘粒含量——夏季风的良好替代指标

通过对位于东亚季风区尾闾部位的沙沟剖面、东部半湿润区王官剖面、东部湿润区扣马剖面的气候代用指标的分析发现 ,黄土地层中 <5 μm的粘粒含量指标对各剖面中黄土-古土壤序列指示得比较清晰 ,可以较好地反映东亚夏季风的变化。对黄土地层中粘粒含量的测试及其环境意义分析以及与经典的东亚夏季风的替代指标———磁化率、红度指标 (a )的对比分析发现 ,粘粒含量指标的意义比较明确 ,适应范围更广 ,灵敏性也较高 ,是一比较可靠的、新的东亚夏季风的良好替代指标。     

华南三省(自治区)部分西番莲种植区花叶病病原检测及EAPV多聚蛋白基因序列分析

<正>西番莲(Passiflora edulis Sims.)是热带亚热带地区重要经济作物,我国福建、广东、广西、海南等地广泛种植[1]。调查发现,我国南方多地西番莲花叶病为害严重,症状表现为叶片花叶、黄化、斑驳、畸形,甚至整株褪绿,严重影响西番莲的产量和品质。已报道能引起西番莲花叶症状的病毒有：黄瓜花叶病毒属(Cucumovirus)的黄瓜花叶病毒(cucumber mosaic virus, CMV),     

基于CP基因的中国云南省烟草TMV群体遗传多样性分析

为探明云南烟草上烟草花叶病毒(tobacco mosaic virus, TMV)的群体遗传多样性特征, 本研究使用TMV外壳蛋白(coat protein, CP)基因的特异性引物对采自云南各烟区的疑似烟草花叶病样品进行检测, 通过克隆测序获得138个TMV CP基因序列, 对其进行了一致性比对, 及系统发育、错配分布、遗传变异、群体多样性等分析。变异分析显示, 138条CP基因序列共有变异位点数122个, 占总位点数的25.42%, 变异类型只有核苷酸替换, 核酸多样性为0.018, 单倍型多样性为0.970;一致性比对结果显示, 138条序列的核苷酸和氨基酸序列一致性均为96%～100%; 重组分析未检测到重组信号;对来自云南烟草, NCBI上其他地区烟草及云南地区其他寄主的TMV分离物的CP基因进行系统发育分析, 结果显示, 所有TMV分离物在进化上可分为4个组, 本试验获得的分离物分布在1、2、3组, 其中只有来源昭通地区的分离物倾向于聚成簇, 表明云南烟草TMV分离物的适应性进化受地理适应性所驱动, 与寄主适应性基本无关;错配分布分析显示, 云南烟草TMV群体呈多峰分布, 表明该群体近期未经历群体扩张事件; 群体间遗传分化分析结果表明, 除昭通和曲靖烟草TMV群体与其他TMV群体之间很容易发生遗传漂变促使群体发生遗传分化外, 其余大部分TMV群体之间的基因流都可以抵制遗传漂变。本研究首次报道了云南各烟区TMV分离物群体遗传变异情况, 研究结果可为TMV的抗病育种和制定更为有效的防治策略提供重要参考。     

东亚副热带急流经向位置对中国西北东部盛夏降水的影响

选取国家气象信息中心整编的中国179个气象站逐日降水资料,以及NCEP/NCAR逐月再分析资料,在分析1979-2017年西北地区东部的盛夏(7、8月)降水变化特征的基础上,利用东亚副热带西风急流经向位置指数,重点讨论东亚副热带西风急流经向位置变化与西北地区东部盛夏降水的关系,以期进一步提高对西北地区旱涝灾害的预测水平。结果表明:在东亚副热带西风急流中心经向位置异常偏北年,西北地区东部偏北区域盛夏降水较常年多,而西北地区东部偏南区域盛夏降水较常年少,反之亦然。表现出东亚副热带西风急流经向位置变化对西北地区东部盛夏降水影响的南北带状反向分布特征。     

西番莲中夜来香花叶病毒实时荧光定量PCR检测方法的建立及应用

夜来香花叶病毒(telosma mosaic virus, TeMV)是对西番莲危害较大的一种病毒病原。根据病毒末端结合蛋白(VPg)序列设计引物, 建立了以Vpg-334F/506R为特异性引物, 退火温度54℃, 引物浓度0.6 μmol/L的SYBR Green Ⅰ实时荧光定量PCR检测方法。该方法可特异性扩增TeMV基因组6 483~6 675 nt区域, 所得标准曲线扩增效率为102.77%, 决定系数为0.996 1, 最低检测浓度为2.370×10 2 拷贝/μL, 灵敏度是普通PCR的1 000倍。应用该方法对接种TeMV的西番莲进行检测, 发现接种3 d后可在叶片中检测到TeMV, 定量分析不同温度下TeMV在叶片中的积累, 发现26~28℃下病毒积累速度最快, 且植株症状表现与病毒积累量密切相关。对赣南地区采集的76份西番莲田间样品进行检测, 共检出71份阳性样品, 检出率为93.4%。综上, 本研究建立的实时荧光定量PCR方法特异性强, 灵敏度高, 适于TeMV的快速检测。     

红火蚁入侵的种群生物学与行为遗传学

红火蚁是广布性以及入侵危害性最强的昆虫类群之一。它有很多的生物学特性适合其入侵、定殖以及扩散。该类害虫在入侵时以及入侵后在种群生物学和行为遗传学上发生了一系列的变异,使其成为一种入侵成功的外来生物。     

太阳辐射变化对东亚内陆大气粉尘含量影响的数值试验

利用美国大气研究中心(NCAR)的公用气候模式(CCM3)与一个粉尘释放和沉降模式(DEAD)相嵌套的模式CCM3-DEAD,研究了太阳常数改变所引起的太阳辐射变化对东亚大气粉尘含量的可能影响.数值试验结果表明,当太阳常数减小1%后,东亚内陆干旱区大部分地区上空的大气粉尘浓度、粉尘释放通量、粉尘沉降通量均有所增加.在中国北方及中蒙边境一带,大气粉尘浓度增加比较明显,最高增加量可达到70 mg/m2,在其周边地区浓度变化在10～60 mg/m2之间.同时,4种粒径(0.1～1.0,1.0～2.5,2.5～5.0,5.0～10.0 μm)的粉尘释放通量和沉降通量普遍增加,其中1.0～2.5 μm粒级的粉尘释放通量增加最为显著,占总增加量的32%,而5.0～10.0 μm粒级的粉尘沉降通量增加占总沉降通量增加量的58.5%,即太阳辐射减小促进了细颗粒的释放和粗颗粒的沉降.初步分析发现,东亚内陆干旱区大气粉尘含量的增加可能与太阳辐射减少所引起的对流层低层大气相对湿度减小及起沙的临界摩擦速度降低有关.     

测试条件对啶虫脒毒土柱防白蚁效果的影响

将预防性杀白蚁药剂施在土壤中形成毒土层是当前控制白蚁为害的主要方法之一。以黄胸散白蚁Reticulitermes flaviceps为对象,啶虫脒为供试药剂,在室内进行毒土柱防白蚁效果测定。结果表明,供试白蚁数量和食物供应与否均对药效试验评价结果有较大影响,毒土柱长度对测试结果的影响与土壤中药剂浓度有关。当毒土柱长度达到10 cm时,所测结果即可反应药剂对白蚁的阻杀效果。用毒土柱法测定预防药剂防白蚁的效果时,建议用10 cm长的毒土柱,每个重复的白蚁数为工蚁100头,并用湿润滤纸片作为供试白蚁的食物和水源。     

抗源西科麦2028抗条锈病遗传的初步分析

<正>小麦条锈病是由小麦条锈菌Puccinia striiformis f.sp.tritici引起的叶部病害,在我国多地冬麦区暴发流行,损失巨大。目前,小麦条锈菌生理小种CYR32、CYR33和Su11-4等为优势流行小种(韩德俊,2010);此外,在四川毒性和致病性更强的V26已渐成新的优势小种(任勇等,2014),当前小麦生产面临严重威胁,积极寻找小麦条锈病新抗源,选育     

First report of an insect pest on Passiflora tenuifila Killip (Passifloraceae)

The genus Passiflora L. has more than 400 species, most of which occur natively in tropical and subtropical regions of South America. The fruit of Passiflora tenuifila Killip, one of the native species of Brazil, has great potential for commercial use by pharmaceutical and cosmetic industries, due to its high content of phenolic compounds, which are natural antioxidants. The study was conducted in two areas located in Tocantins and in the Federal District, Brazil. The presence of globose lumps and thickening of the stems on plants of Pa. tenuifila was observed on plants in these areas. Injured samples taken from both locations were analyzed and showed the presence of larvae and pupae of a Curculionidae, which completed their life cycle in the laboratory. The adults were identified as Philonis crucifer (Brèthes) (Coleoptera: Curculionidae). In Tocantins, 100% of the plants in the trial area were infested, while in the Federal District trial the incidence of infestation was 20.3%. This is the first report of an insect on Pa. tenuifila, indicating the need to develop management strategies for this pest to be applied in commercial crops of this Passiflora species.     

Impact of Sugarcane yellow leaf virus on Sugarcane Yield and Juice Quality in Réunion Island

Sugarcane yellow leaf virus (SCYLV) was first detected in sugarcane of Réunion Island in 1997. A field experiment was undertaken to assess the potential impact of this virus on sugarcane production. The agronomic characteristics of SCYLV-infected plants were compared to those of virus-free plants of three sugarcane cultivars (R570, R577 and R579) which occupy more than 90% of the cultivated sugarcane area on Réunion Island. In the plant crop, significant losses in stalk weight (28%) and in sugar content (11%) were detected for cultivar R577, but not for either of the two other cultivars. In the first ratoon crop, yield reduction was detected for cultivar R577 (37%), but also for cultivar R579 (19%). Cultivar R577 also showed significant losses in sugar content (12%) due to reduced amount and quality of extracted cane juice. No yield reduction was found for cultivar R570, although stalk height and diameter were reduced in SCYLV-infected canes of this cultivar in the first ratoon crop. Leaf yellowing was observed at harvest of plant and ratoon crops when sugarcane was no longer irrigated, and 10–59% of symptomatic stalks could be attributed to the presence of SCYLV. The most severe yellowing symptoms were related to infection of sugarcane by the virus.     

5种杀虫剂防治西番莲大斑芫菁的药效试验

通过室内药剂试验 ,发现敌百虫1000倍液、辛硫磷1000倍液、多虫清2000倍液、功夫4000倍液、巴丹1000倍液等 5种药剂都对大斑芫菁有较好的胃毒效果。其中敌百虫触杀效果较好 ,见效快、持效长 ,在施药12h后 ,大斑芫菁平均死亡率达到100%。通过对敌百虫浓度梯度试验表明 ,在生产上使用90%敌百虫原粉3000倍液防治西番莲大斑芫菁较理想 ,既可收到较好的防治效果 ,又能降低生产成本     

Regulatory Mechanisms and Dynamics of an Island Population of Clethrionomys glareolus (Schreber, 1780)1

A scheme of density regulation in an island population of Clethrionomys glareolus (Schreber) is presented. The key factor for the changes in numbers was mortality of untrappable voles. A peak in population numbers followed low mortality of the spring generation, and, in peak years, mortality of the autumn generation was always high. An experimentally enriched food supply resulted in low mortality of both the spring and autumn generations. Natality, which is usually stable, increased slightly as a consequence of the additional food supply. This was due to an earlier start of the breeding season (6 weeks earlier) and to an increase in numbers of mature (i.e. capable of reproduction) females.     

云南省德宏州亚洲玉米螟发生动态及主要危害区域调查

利用亚洲玉米螟信息素监测亚洲玉米螟在云南省德宏州的种群动态,结果表明,亚洲玉米螟在德宏州发生可分为两种类型,一是在低海拔(1 000m)地区亚洲玉米螟全年均有发生,二是在高海拔(1 200m)地区集中在4-8月份发生为害。亚洲玉米螟在德宏州世代重叠严重,因海拔高度不同,每年发生4~7代。高海拔地区以老熟幼虫滞育越冬,低海拔地区部分幼虫不滞育,但种群数量较低。田间调查结果表明,亚洲玉米螟在德宏州分布较广,不同地区发生为害存在着显著性差异,发生严重地区亚洲玉米螟为害率最高可达97%,为害级别多为3~4级,集中分布于东经97°51′~97°60′区间,呈带状分布。亚洲玉米螟发生为害在不同经度上存在显著性差异,平均为害率和为害级别分别是57.75%和4级。在不同海拔和纬度之间亚洲玉米螟发生概率也存在显著差异,在901~1 100m和1 301~1 500m海拔和24°46′~25°59′纬度之间发生概率高。     

Population genetic analysis of Phytophthora infestans in northwestern China

Late blight caused by Phytophthora infestans is the most devastating disease of potato worldwide. To understand the P. infestans population structure and dynamics in northwestern China, 959 single‐lesion isolates were purified in three consecutive years (2009–2011) and were characterized for mating type, pathotype, mtDNA haplotype and molecular variation at eight SSR loci. The results showed that the distribution of mating types changed significantly over years, with self‐fertile isolates dominant in 2010 and 2011. SSR genotyping distinguished 959 isolates into 151 genotypes, and association analysis indicated that P. infestans populations in 2010 and 2011 were strictly asexual while in 2009 they showed signs of sexual reproduction. Population analysis showed that the majority of genetic variation was within P. infestans populations. Isolates sharing identical SSR genotypes were detected in distant regions, indicating that migration of P. infestans could have occurred between regions. Pathogenicity assays on a set of potato differential lines containing R1 to R11 resistance genes detected four pathotypes from 74 selected isolates, with the pathotype virulent against all 11 R genes being dominant. Three mtDNA haplotypes (Ia, IIa, IIb) were detected with Ia being dominant among 507 isolates examined. Phylogenetic analysis indicated that P. infestans populations in northwestern China are distant from European lineages including 13‐A2 (blue‐13) at the time of this survey. The results have implications for the trade of healthy seed tubers as a means of managing late blight.