长毛孜然芹,中国伞形科一新记录种

报道了中国伞形科（Apiaceae）孜然芹属一新记录种：长毛孜然芹[Cuminum borszczowii（Regel et Schmalh.）Koso-Pol.]。该物种在形态上与孜然芹（C.cyminum）相近,与后者的区别在于总苞宽披针形具较宽的膜质边缘,不反折,比伞辐短;果实密被长毛。提供了该种详细的形态学描述及图版。凭证标本保存在新疆农业大学标本馆（XJA）和中国科学院新疆生态与地理研究所标本馆（XJBI）。     

丛枝菌根真菌促进南美蟛蜞菊生长及对难溶磷的吸收

为了解2种丛枝菌根真菌(AMF)摩西管柄囊霉(Funneliformis mosseae, FM)和地表球囊霉(Glomus versiforme, GV)对入侵植物南美蟛蜞菊(Wedelia trilobata)的生长和对难溶性磷酸盐利用的影响,采用沙培盆栽方式,研究了南美蟛蜞菊在接种AMF与添加难溶性磷酸盐的生长和磷含量的变化。结果表明,在磷限制环境下FM对南美蟛蜞菊的侵染率达55%～69%,GV的侵染率达到63%～80%。添加难溶性磷酸盐后,2种AMF均促进了南美蟛蜞菊茎的伸长(FM:+46%; GV:+65%)、总生物量的增加(FM:+27.2%; GV:+40%)和磷含量的增加(FM:+36.6%; GV:+40.7%)。对比FM,GV对植物利用难溶性磷有更显著的促进作用。因此,南美蟛蜞菊与2种AMF形成的共生体系可以促进植物生长和对营养资源的利用,提高对难溶性磷的吸收效率可能使得南美蟛蜞菊在营养贫乏的环境中更好地建立种群。     

优良单株家系辣木叶的表型性状分析

为挖掘辣木(Moranga oleifera)优良种质资源,对30个优良单株家系的叶片表型性状进行研究。结果表明,除叶形外,辣木不同家系间的叶柄和叶片颜色、复叶数、复叶柄长度和直径、复叶间距、叶长、叶宽均存在不同程度的差异。复叶数与复叶柄长度和直径、复叶间距、叶长、叶宽呈极显著正相关;主成分分析表明,叶长、叶宽、复叶柄长度和直径、复叶间距、叶柄和叶片颜色是区分辣木不同家系最主要的叶片性状指标。聚类分析结果表明,30个辣木家系可分为3大类,叶片表型性状存在显著差异的家系的遗传距离较远。因此,叶柄和叶片颜色、复叶数、复叶柄长度和直径、复叶间距、叶长、叶宽将为直观区分辣木家系提供参考。     

Cd污染及其与大气CO2浓度升高、N添加复合作用对大叶相思生长的影响

为了解Cd污染胁迫下树木对CO_2浓度升高、N添加及其复合作用的响应,应用开顶箱,探讨Cd及其与CO_2、N的复合作用对大叶相思(Acacia auriculiformis)基径、树高和生物量的影响。结果表明,Cd添加抑制大叶相思基径、树高和生物量的增长,并且具有时间滞后性;大气CO_2浓度升高、N添加及CO_2+N均有缓解Cd对植物生长抑制作用的趋势,其中, N添加更能促进大叶相思基径的生长,树高生长则对CO_2升高更为敏感;在Cd污染土壤中,N添加的缓解作用最显著。因此,氮肥管理是重金属污染土地修复初期促进植物修复的重要策略。     

新一代遥感技术助力生态系统生态学研究

随着气候变化和人类活动的加剧, 生态系统正处于剧烈变化中, 生态学家需要从更大的时空尺度去理解生态系统过程和变化规律, 应对全球变化带来的威胁和挑战。传统地面调查方法主要获取的是样方尺度、离散的数据, 难以满足大尺度生态系统研究对数据时空连续性的要求。相比于传统地面调查方法, 遥感技术具有实时获取、重复监测以及多时空尺度的特点, 弥补了传统地面调查方法空间观测尺度有限的缺点。遥感通过分析电磁波信息从而识别地物属性和特征, 反演生态系统组成、能量流动和物质循环过程中的关键要素, 已逐渐成为生态学研究中必不可少的数据来源。近年来, 随着激光雷达、日光诱导叶绿素荧光等新型遥感技术以及无人机、背包等近地面遥感平台的发展, 个人化、定制化的近地面遥感观测逐渐成熟, 新一代遥感技术正在推动遥感信息“二维向三维”的转变, 为传统样地观测与卫星遥感之间搭建了尺度推绎桥梁, 这也给生态系统生态学带来了新的机遇, 推动生态系统生态学向多尺度、多过程、多学科、多途径发展。因此, 该文从生态系统生态学角度出发, 重点关注陆地生态系统中生物组分, 并分别从生态系统类型、结构、功能和生物多样性等方面, 结合作者在实际研究工作中的主要成果和该领域国际前沿动态, 阐述遥感技术在生态系统生态学中的研究现状并指出我国生态系统遥感监测领域发展方向及亟待解决的问题。     

气候变暖背景下青藏高原草本植物物候变化空间换时间预测

气候变暖背景下的植物物候变化广受关注, 然而常用的植物物候变化预测模型未充分考虑植物对环境的适应性, 给预测结果带来了较大的不确定性。该文基于2002-2011年青藏高原10个站点的地面物候观测资料以及年平均气温数据, 对空间换时间模型预测车前(Plantago asiatica)和蒲公英(Taraxacum mongolicum)各主要物候事件(展叶始期、开花始期和黄枯普遍期)变化的可行性及其在升温背景下的变化规律进行了分析。首先利用不同海拔高度的气温和物候事件分别与地理因子(经度、纬度和海拔)建立多元线性回归模型, 然后在此基础上剔除经度和纬度的影响, 单独考察海拔变化所引起的气温与植物物候变化, 最后以海拔高度作为桥梁来考察物候变化与温度变化的关系。结果表明, 采用各站点对应的海拔高度来模拟年平均气温空间差异的R²均大于0.89, 表明海拔梯度可以用来反映时间尺度下的年际温度变化; 车前和蒲公英各物候事件发生日期拟合值均与海拔高度变化关系显著, R²均大于0.70, 表明海拔变化是影响它们各物候事件变化的主要地理因子; 在物候事件发生日期拟合值和年平均气温拟合值的回归方程中, R²均大于0.93, 说明基于不同海拔高度模拟得到的年平均气温变化可以对时间尺度上车前和蒲公英的物候事件变化进行预测。空间换时间预测表明, 温度每升高1 ℃, 车前展叶始期和开花始期分别提前5.1和5.4 d, 而黄枯普遍期推迟4.8 d; 蒲公英展叶始期和开花始期分别提前6.5和7.8 d, 而黄枯普遍期推迟6.7 d。     

二色仙人掌，中国仙人掌科一新归化种

2019年4-6月,在江苏省西南部句容市郭庄镇虬山,首次发现二色仙人掌(Opuntia cespitosa Rafinesque)归化种群。该种群主要生长在海拔46～90 m的废弃采石场上,分布范围东西长510 m,南北宽260 m,面积约13.26 hm2。二色仙人掌开花结实的成年植株共计910棵,其中最大灌木平卧茎长轴上叶状茎10个,树龄可达10 a,大概在2010年就生长于虬山。在句容虬山采石场关闭时,采石场工作人员可能将盆栽的二色仙人掌就地丢弃,从而导致该归化种群的发展。比较了二色仙人掌与中国仙人掌属已知其余4种归化植物的形态特征,并编制了分种检索表。此外,讨论了二色仙人掌的传播机制及其入侵风险。     

慢性乙型肝炎患者TBIL、ALT、γ GT、 TBA水平变化及肠道菌群分析

目的研究慢性乙型肝炎患者总胆红素(TBIL)、丙氨酸氨基转移酶(ALT)、γ-谷氨酰转肽酶(γ-GT)、总胆汁酸(TBA)水平及肠道菌群变化。方法选取2017年10月至2018年10月我院收治的慢性乙型肝炎患者80例为观察组,选取同期来我院进行体检的100例健康者为对照组,对比两组对象肝功能指标、血清炎性因子水平和肠道菌群数量。结果观察组患者血清TBIL、ALT、TBA和γ-GT水平显著高于对照组(均P0.05)。观察组患者血清CRP、TNF-α和IL-6水平显著高于对照组(均P0.05)。观察组患者肠道肠杆菌科、普雷沃菌属、拟杆菌属、梭菌属细菌及白假丝酵母数量显著高于对照组(均P0.05)。两组对象肠道瘤胃球菌属、双歧杆菌属、乳杆菌属细菌及粪肠球菌数量差异无统计学意义(均P0.05)。结论慢性乙型肝炎患者TBIL、ALT、γ-GT、TBA水平高于健康人群,炎性因子水平也高于正常人群,且存在一定程度的肠道菌群失调。提示肠道菌群结构变化可能对肝脏组织产生一定的损伤。     

Increased diversity and concordant shifts in community structure of coral‐associated Symbiodiniaceae and bacteria subjected to chronic human disturbance

Both coral‐associated bacteria and endosymbiotic algae (Symbiodiniaceae spp.) are vitally important for the biological function of corals. Yet little is known about their co‐occurrence within corals, how their diversity varies across coral species, or how they are impacted by anthropogenic disturbances. Here, we sampled coral colonies (n = 472) from seven species, encompassing a range of life history traits, across a gradient of chronic human disturbance (n = 11 sites on Kiritimati [Christmas] atoll) in the central equatorial Pacific, and quantified the sequence assemblages and community structure of their associated Symbiodiniaceae and bacterial communities. Although Symbiodiniaceae alpha diversity did not vary with chronic human disturbance, disturbance was consistently associated with higher bacterial Shannon diversity and richness, with bacterial richness by sample almost doubling from sites with low to very high disturbance. Chronic disturbance was also associated with altered microbial beta diversity for Symbiodiniaceae and bacteria, including changes in community structure for both and increased variation (dispersion) of the Symbiodiniaceae communities. We also found concordance between Symbiodiniaceae and bacterial community structure, when all corals were considered together, and individually for two massive species, Hydnophora microconos and Porites lobata, implying that symbionts and bacteria respond similarly to human disturbance in these species. Finally, we found that the dominant Symbiodiniaceae ancestral lineage in a coral colony was associated with differential abundances of several distinct bacterial taxa. These results suggest that increased beta diversity of Symbiodiniaceae and bacterial communities may be a reliable indicator of stress in the coral microbiome, and that there may be concordant responses to chronic disturbance between these communities at the whole‐ecosystem scale.     

Heterogeneous genetic invasions of three insecticide resistance mutations in Indo‐Pacific populations of Aedes aegypti (L.)

Nations throughout the Indo‐Pacific region use pyrethroid insecticides to control Aedes aegypti, the mosquito vector of dengue, often without knowledge of pyrethroid resistance status of the pest or origin of resistance. Two mutations (V1016G + F1534C) in the sodium channel gene (Vssc) of Ae. aegypti modify ion channel function and cause target‐site resistance to pyrethroid insecticides, with a third mutation (S989P) having a potential additive effect. Of 27 possible genotypes involving these mutations, some allelic combinations are never seen whereas others predominate. Here, five allelic combinations common in Ae. aegypti from the Indo‐Pacific region are described and their geographical distributions investigated using genome‐wide SNP markers. We tested the hypothesis that resistance allele combinations evolved de novo in populations versus the alternative that dispersal of Ae. aegypti between populations facilitated genetic invasions of allele combinations. We used latent factor mixed‐models to detect SNPs throughout the genome that showed structuring in line with resistance allele combinations and compared variation at SNPs within the Vssc gene with genome‐wide variation. Mixed‐models detected an array of SNPs linked to resistance allele combinations, all located within or in close proximity to the Vssc gene. Variation at SNPs within the Vssc gene was structured by resistance profile, whereas genome‐wide SNPs were structured by population. These results demonstrate that alleles near to resistance mutations have been transferred between populations via linked selection. This indicates that genetic invasions have contributed to the widespread occurrence of Vssc allele combinations in Ae. aegypti in the Indo‐Pacific region, pointing to undocumented mosquito invasions between countries.