暗期干扰对棉铃虫两个不同地理种群滞育抑制作用的比较

至今,所测试昆虫的光周期反应均表明,光周期反应对暗期干扰高度敏感,短暂的光脉冲都可在不同程度上逆转长夜效应,抑制滞育的发生。在研究了棉铃虫Helicoverpa armigera泰安种群(36.15°N,116.59°E)和喀佐种群(41.34°N,120.27°E)光周期反应的基础上,在滞育诱导的短光周期下(L12:D12和L9:D15),分别测试了暗期不同时段1h光脉冲对这两个不同地理种群滞育抑制的影响。25和22℃下的光周期反应显示了泰安种群在长暗期11—14 h的滞育率均显著低于喀佐种群;泰安种群的临界暗长分别为11.7 h和11.5 h,喀佐种群分别为10.5 h和10.3 h,泰安种群均比喀佐种群长1.2 h。在所测试的暗期干扰实验中,除了极少数光脉冲干扰点外,泰安种群蛹滞育率显著低于喀佐种群,但两者的滞育反应曲线基本相似。在短光周期L9:D15下,泰安种群和喀佐种群均显示了光脉冲落入暗期的第9—11小时最有效地抑制了滞育的发生。在短光周期L12∶D12下,泰安种群和喀佐种群在25℃时均显示了光脉冲落入暗期的第3—4小时和第10小时导致了最低的滞育发生;但在22℃时,喀佐种群只在暗期的第3—4小时显示了最高的滞育抑制。这些结果揭示了偏南的泰安种群对暗期干扰的敏感性强于偏北的喀佐种群,但这两个地理种群的最高光敏感位点基本相同。     

模拟氮沉降和降雨对华西雨屏区常绿阔叶林土壤呼吸的影响

从2013年12月至2014年11月,通过野外原位试验,对华西雨屏区常绿阔叶林进行了模拟氮沉降和降雨试验,采用LI-8100土壤碳通量分析系统(LI-COR Inc.,USA)测定了对照(CK)、氮沉降(N)、减雨(R)、增雨(W)、氮沉降+减雨(NR)、氮沉降+增雨(NW)6个处理水平的土壤呼吸速率,并通过回归方程分析了温度和湿度与土壤呼吸速率间的关系。结果表明:(1)氮沉降和增雨抑制了常绿阔叶林土壤呼吸速率,减雨促进了常绿阔叶林土壤呼吸速率。(2)减雨使华西雨屏区常绿阔叶林土壤呼吸年通量增加了258 g/m~2,而模拟氮沉降和增雨使华西雨屏区常绿阔叶林土壤呼吸年通量分别减少了321g/m~2和406g/m~2。(3)减雨增加了土壤呼吸的温度敏感性,模拟氮沉降和增雨降低了土壤呼吸的温度敏感性。(4)模拟温度和湿度与土壤呼吸速率间回归方程分析表明,土壤水分对土壤呼吸速率的影响较小。(5)模拟氮沉降和增雨处理减少土壤微生物生物量碳、氮的含量,减雨处理增加了土壤微生物生物量碳、氮的含量。(6)模拟氮沉降和降雨对华西雨屏区土壤CO_2释放的影响未表现出明显的交互作用。     

Genetic relationship between parasitized and non‐parasitized Haloxylon ammodendron in the Alxa Desert

Abstract Haloxylon ammodendron (C. A. Mey.) Bunge is a host for the holoparasitic plant Cistanche deserticola Y. C. Ma, the original source of medicinal material known as Herba Cistanchis. The inter‐simple sequence repeat marker was used to assess the genetic variations and relationships among six accessions of H. ammodendron with a total of 120 individuals collected from three localities in the Alxa Desert, Inner Mongolia, China. At each locality, individuals both parasitized (PP) by C. deserticola and non‐parasitized (NP) were sampled. The results showed that Nei's gene diversity and Shannon's index of PP accessions were higher, but were not significantly different, from those of NP accessions. An unweighted pair‐group method arithmetic average dendrogram showed two clusters, one that included all PP accessions, and the other the NP accessions. Genetic differentiation therefore existed between PP and NP accessions, which might be attributed to low gene flow between the NP and PP groups (Nm<1). However, the relationship between genetic distance and geographic distance within each group, although not statistically significant in this study, might be associated with high gene flow in both the NP and PP groups.     

Preliminary phylogeny of the genus Copidosoma (Hymenoptera,Encyrtidae), polyembryonic parasitoids of Lepidoptera

The genus Copidosoma (Hymenoptera: Chalcidoidea: Encyrtidae) is a diverse group of polyembryonic parasitoids of Lepidoptera, including species that have the potential to control agricultural and forestry pests. Moreover, some species of Copidosoma display polyembryony. Despite their economic and scientific importance, little is known about the phylogeny of Copidosoma and its relations to other groups of Encyrtidae. Here we infer the phylogenetic relationships of this genus from nucleotide sequences of two nuclear (18S and 28S) and one mitochondrial (COI) genes. Forty‐four species of Copidosoma and three species of Copidosomopsis plus two outgroup species are included in Maximum Parsimony and Bayesian analyses. Copidosomopsis syn. n . is proposed as a junior synonym of Copidosoma based on phylogenetic analysis results. Each of nine identical clades, resulting from both analyses, is proposed as informal species group: cervius group (cervius, chalconotum and serricorne), recovered as the basal lineage of Copidosoma; nacoleiae group (nacoleaie, meridionalis and an undescribed species, formerly belonging to the genus Copidosomopsis); boucheanum group (boucheanum, terebrator, peticus, phaloniae, ancharus, tibiale and sosares); noyesi group (noyesi and probably undescribed related species); albipes group (albipes and coimbatorense); varicorne group (including varicorne and subalbicorne in one subclade, and aretas and fuscisquama in the other); thebe group (thebe and probably undescribed related species); exiguum group (exiguum and probably undescribed related species); floridanum group (floridanum, primulum, transversum, truncatellum and agrotis). Host associations of the genus and host specificity of recognized groups are discussed. The current work offers a foundation for a comprehensive phylogeny of Copidosoma and the possibility to reconstruct cophylogeny between Copidosoma and their lepidopteran hosts.     

青海省南部治多-杂多一带早石炭世有孔虫动物群

在青海省南部的治多—杂多一带1／25万地质填图中，于杂多群中首次发现非筵有孔虫，建立2个组合，即Endothyra-Mediocris—Archaediscus组合和Bradyina-Endothyranopsis组合，地质时代为早石炭世大塘期德坞期，与华南、塔里木盆地、西秦岭、前苏联等地同期生物群可很好地对比，同时结合大冢相似系数的计算表明，青海南部地区在早石炭世属于特提斯大区华夏生物区华南省。     

以红皮病和口腔念珠菌感染为主要表现AIDS1例

报道以红皮病为突出表现AIDS 1例.患者男性,64岁,因“全身发疹2个月,伴发热1周”收入院.查体发现体重明显下降,双睑结膜充血,口腔上颚,颊黏膜密集点滴状白色伪膜,全身弥漫暗红色斑片,伴有褐色痂皮脱屑.口腔黏膜真菌涂片(+),HIV-1(+).确诊AIDS,红皮病,口腔念珠菌感染.后死于肺部感染.     

TLR2在红色毛癣菌感染中对角质形成细胞分泌γ-IFN和IL-8的影响

目的 观察红色毛癣菌刺激人角质形成细胞后γ-IFN及IL-8浓度的变化,以及TLR2对γ-IFN和IL-8分泌的影响.方法 用红色毛癣菌悬液分别刺激TLR2抗体处理前后的角质形成细胞,采用ELISA方法检测不同时间点细胞上清液中γ-IFN及IL-8的浓度,并设置阴性对照;比较TLR2抗体处理的后γ-IFN及IL-8浓度的变化.结果 红色毛癣菌刺激角质形成细胞后,γ-IFN及IL-8浓度明显升高(P＜0.05),4h即开始,至16 h达高峰;用TLR2抗体中和TLR2后,上清液中IL-8的浓度在2h、4h、8h、16h各时间点较中和前低,差异有统计学意义(P＜0.05);γ-IFN的浓度2h、4h、8h时间点较中和前低,差异有统计学意义(P＜0.05),而在16h时间点,上清液中γ-IFN的浓度与中和前比较略低,但差异没有统计学意义(P＞0.05).结论 红色毛癣菌刺激角质形成细胞后,可促进角质形成细胞分泌γ-IFN和IL-8;TLR2在角质形成细胞分泌γ-IFN和IL-8的过程中发挥重要的调节作用.