干旱胁迫对大豆生长的影响及抗旱性评价方法与指标筛选

2014-2015年在年降雨量不足40 mm的敦煌市,设干旱和正常灌水两个处理,通过测定12份大豆品种的8个形态指标(株高、主茎节数、有效分枝数、单株荚数、单株粒数、单株粒重、单株生物量和百粒重)及小区产量,采用改进抗旱指数法及权重隶属函数值D对其进行抗旱性评价,并筛选出3份不同抗旱类型的大豆品种进行生理指标测定,验证该方法和指标。结果显示,与灌水处理(CK)相比较,干旱胁迫下的8个形态指标及产量,2014年除有效分枝数及百粒重差异不显著外,其余考察性状均达到了极显著差异,2015年所有考察表型性状均达到极显著差异;两年权重隶属函数法评价结果显著相关,小区产量与两年两种评价方法极显著相关;两种处理下,中度抗旱(中黄24)、弱抗旱品种(WDD00172)的SOD活性、POD活性、CAT活性、丙二醛含量、可溶性糖含量差异极显著,且与权重隶属函数值D显著相关,而强抗旱品种(晋豆21号)中SOD活性、POD活性、脯氨酸含量差异不显著,且6个生理指标与权重隶属函数值D均不相关。因此,权重隶属函数法和小区产量可作为大豆抗旱性评价单一可靠的方法与指标。     

Phenotypic variations in seed and fruit traits of Liquidambar formosana populations

为了明确我国枫香树(Liquidambar formosana)种子与果实表型变异程度和变异规律, 采用方差分析、相关分析和回归分析等方法对36个天然种群枫香树的10个种子与果实的表型性状在种群间和种群内表型变异和地理变异模式进行探讨。研究结果表明, 枫香树平均表型分化系数为57.55%, 种群间的变异是其表型变异的主要来源; 种子和果实表型性状的变异丰富, 变异幅度为10.05%-24.31%, 平均变异系数为15.83%; 不同种群间变异差别明显, 安福种群平均变异系数最大(16.73%), 建阳种群平均变异系数最小(11.48%)。枫香树多数种子与果实表型性状在地理变化上是随机的, 地理相近种群在表型上没有显著相关性。地理气候因子中1月平均气温、海拔和纬度对种子与果实性状起主要的影响。种子与果实性状与海拔相关分析表明, 枫香树种子长宽比随海拔的升高而减小, 种子长宽比可以推测种群所在的海拔高度。探讨枫香树种群表型多样性, 可为野生优异种质的收集、多目标品种选育等工作提供依据。     

Seasonal variations of mercury levels and human health risk in vegetables from Arid Oasis (Shihezi city), Xinjiang,Northwest China

The purpose of this study was to investigate the seasonal variations of mercury levels and human health risk in vegetables that were collected from farmland, home garden, and plastic greenhouse in summer and winter 2016 in Arid Oasis (Shihezi city), Xinjiang, Northwest China. The results showed that the levels of mercury in fresh vegetables were lower in winter (0.003–0.025 mg·kg^?1) than in summer (0.001–0.035 mg·kg^?1). Single factor pollution (P) in vegetables indicated that all vegetables were polluted in diverse levels. The exceeding rate in different vegetables was 0.00% to 88.89% in summer and 0.00% to 100% in winter compared with limits of pollutants in vegetables. The value of bio-concentration factor (BCF) revealed that the mercury absorption capacity of 10 species vegetables decreased in the following order: pea seedling > spinage > caraway > lettuces > pakchoi > celery > crowndaisy chrysanthemum > chives > spinach > shallot. The daily intake (DI) and target hazard quotient (THQ) of mercury for children (2–12 years), young adults (18–45 years), and quinquagenarian (>45 years) indicated that non-carcinogenic values were below the threshold values except one sampling sit from farmland around the industrial parks. Furthermore, the THQ of open field in summer was higher than plastic greenhouse in winter. Under the same pollution level, children had more non-carcinogenic risk than young adults and quinquagenarian.     

榄仁树的生理和生物学特性

为了解榄仁树(Terminalia catappa)的生理生态特性,对西沙群岛永兴岛上自然生长的榄仁树的叶片形态、生理特征、营养元素含量以及根际土壤特征进行了研究。结果表明,榄仁树具有比叶面积低、叶片厚、气孔密度小等形态特征。叶绿素a/b为2.25∶1,低于理论值3∶1。叶片的SOD和POD活性较低,脯氨酸和ABA含量较高。植物体内养分含量较高,适生土壤养分含量低。这说明榄仁树叶片的吸收利用光能能力较强,保水能力较好,有较强的抗干旱和抗逆能力,适生于贫瘠的土壤并保持较高的叶片营养。因此,榄仁树是一种能够适应高温、干旱、贫瘠等恶劣生境条件的树种,可作为热带珊瑚岛植被恢复的工具种和园林绿化树种。     

钦州湾秋季和春季浮游动物分布特征及影响因素

为了解钦州湾浮游动物群落的时空分布特征及与主要环境因子的关系,于2014年10月和2015年3月进行了秋季和春季两航次的调查。结果表明:该海湾的浮游动物群落有明显的季节变化。秋季共鉴定出12类87种,其中优势种有太平洋纺锤水蚤(Acartia pacifica)、肥胖三角溞(Evadne tergestina)、亨生莹虾(Lucifer hanseni)、百陶箭虫(Sagitta bedoti)和长尾类幼虫(Macrura larvae);春季共鉴定出11类48种,优势种为中华哲水蚤(Calanus sinicus)和太平洋纺锤水蚤;秋季浮游动物的平均丰度、生物量和多样性指数(528.92个/m~3、110.60 mg/m~3和2.22)均高于春季(48.30个/m~3、61.10 mg/m~3和1.70)。空间分布上,钦州湾外湾浮游动物丰度、生物量和多样性指数的平均值皆高于内湾。多维尺度分析表明,秋季内湾群落相似性较高,春季外湾浮游动物群落相似性较高。相关性分析表明盐度与营养盐是影响钦州湾浮游动物分布的主要环境因子。与2011—2012年数据相比,钦州湾浮游动物群落结构已趋于单一化和小型化,以致生物量明显下降。这一现象主要与钦州湾海水富营养化以及大面积高密度牡蛎养殖有密切的关系。     

圆蟾舌蛙鸣声特征分析

为研究体型较小的蛙类的鸣声特征,2012年7~8月,采用录音机和指向性话筒,在野外录制51只雄性圆蟾舌蛙(Phrynoglossus martensii)鸣声并对应测量了录音个体的体重、体长及头宽等体征数据。雄性圆蟾舌蛙的体重为(1.26±0.55)g,体长为(21.04±2.57)mm,头宽为(6.76±0.75)mm。该种蛙可发出广告鸣声和争斗鸣声。广告鸣声为单音节鸣叫,主频(3 782.25±167.78)Hz,3 100~4 349 Hz;基频(1 519.69±70.60)Hz,1 057~1 765 Hz。广告鸣声主频和基频均与体重、体长、头宽呈显著负相关,而音节间隔与体重和头宽呈正相关(相关性分析)。争斗鸣声主频(3 752.64±174.47)Hz,(3 304~4 081)Hz;基频(1 674.88±79.88)Hz,1 367~1 870 Hz。与广告鸣声相比,争斗鸣声的基频显著增高(t=﹣5.374,df=56,P0.001),音节时长和音节间隔显著降低(P0.05),而主频在两种鸣声类型中无显著差异(t=0.436,df=56,P=0.665)(独立样本T检验)。结果表明,作为体型较小的蛙类,体型影响了圆蟾舌蛙的鸣声结构和类型。     

CCR5 Revisited: How Mechanisms of HIV Entry Govern AIDS Pathogenesis

The chemokine receptor CCR5 has been the focus of intensive studies since its role as a coreceptor for HIV entry was discovered in 1996. These studies lead to the development of small molecular drugs targeting CCR5, with maraviroc becoming in 2007 the first clinically approved chemokine receptor inhibitor. More recently, the apparent HIV cure in a patient transplanted with hematopoietic stem cells devoid of functional CCR5 rekindled the interest for inactivating CCR5 through gene therapy and pharmacological approaches. Fundamental research on CCR5 has also been boosted by key advances in the field of G-protein coupled receptor research, with the realization that CCR5 adopts a variety of conformations, and that only a subset of these conformations may be targeted by chemokine ligands. In addition, recent genetic and pathogenesis studies have emphasized the central role of CCR5 expression levels in determining the risk of HIV and SIV acquisition and disease progression. In this article, we propose to review the key properties of CCR5 that account for its central role in HIV pathogenesis, with a focus on mechanisms that regulate CCR5 expression, conformation, and interaction with HIV envelope glycoproteins.     

人工繁育与野外鳄蜥幼体及亚成体形态和健康状况的比较

人工繁育是濒危物种保护的重要手段,但是也会改变物种的表型。为了探究人工繁育对于鳄蜥(Shinisaurus crocodilurus)形态和健康状况的影响,本研究比较了人工繁育鳄蜥与野外鳄蜥新生幼体及亚成体形态特征与细菌感染率。结果发现,人工繁育鳄蜥与野外鳄蜥的新生幼体体型无显著差异,而人工繁育鳄蜥亚成体体型显著大于野外鳄蜥;两个年龄段的人工繁育鳄蜥断尾率均显著低于野外鳄蜥;人工繁育鳄蜥亚成体细菌感染率最高,但是各年龄组种群间的差异不显著。本研究表明,人工环境促进了鳄蜥的生长,减少了鳄蜥被捕食的风险,但有增加鳄蜥感染疾病的可能性,因此在鳄蜥的饲养管理中需要加强疾病防治。     

Identificación de polimorfismos de un solo nucleótido relacionados con la fragilidad

Introduction

The search for biomarkers that can lead to the early diagnosis and thus, early treatment of frailty, has become one of the main challenges facing the geriatric scientific community. The aim of the present study was to identify single nucleotide polymorphisms (SNPs) related to frailty.