甘西鼠尾草一新变型

2004年8月份,我们在巴颜喀拉山南坡考察时,在四川省的壤塘县发现了甘西鼠尾草的个白花变型,生境为海拔3350m的沟谷林缘灌丛,现报道如下。     

褐毛甘西鼠尾注射液对大鼠在体心肌缺血再灌注损伤的保护作用

本实验与丹参进行对比研究云南产鼠尾草属药物褐毛甘西鼠尾对急性心肌缺血再灌注损伤的保护作用。采用结扎大鼠冠脉左前降支方法造成心肌缺血再灌注模型,测定再灌注60 min后血清中CK、LDH、SOD、GSH-Px和MDA含量。实验结果显示:该药可以显著降低心肌缺血再灌注后血清CK、LDH和MDA含量,升高血清SOD和GSH-Px活力(P<0.01,P<0.05)。表明褐毛甘西鼠尾对在体缺血/再灌注心肌有保护作用。     

Sexual Dimorphism of Head Size in Phrynocephalus przewalskii: Testing the Food Niche Divergence Hypothesis

Sexual size dimorphism （SSD） is a general phenomenon in lizards, and can evolve through sexual selection or natural selection. But natural selection, which was thought to operate mainly through reducing the competition be- tween the two sexes （niche divergence hypothesis）, gave rise to a lot of controversy. We tested the niche divergence hypothesis in the toad-headed lizard Phrynocephalus przewalskii by comparing diet composition and prey sizes between males and females. The species was found to be sexual dimorphic, with males having relatively larger snout-vent length, head width, head length, and tail length, while females have relatively larger abdomen length. Based on analysis of 93 studied stomachs, a total of 1359 prey items were identified. The most common prey items were formicid, lygaeid and tenebrionid. The two sexes did not differ in the relative proportions of prey size categories they consumed and the dietary overlap based on prey species was high （O = 0.989）. In addition, the meal size, the volume or any maximal dimension of the largest prey item in the stomach was not explained by the sexes. According to our results, food niche divergence might not play an important role in the SSD evolution ofP. przewalskii.     

不同生境下青海湖裸鲤(Gymnocypris przewalskii)两亚种鳃形态差异及其功能适应

该研究比较观察青海湖裸鲤(Gymnocypris przewalskii)两亚种(青海湖裸鲤指名亚种(Gymnocypris przewalskii przewalskii)和青海湖裸鲤甘子河亚种(Gymnocypris przewalskii ganzihonensis))鳃的形态及显微结构。结果显示,指名亚种的第一鳃弓鳃耙数多、密集且较长,而甘子河亚种则耙数少、稀疏且短;两者的鳃丝间距及鳃小片间距无明显差异,指名亚种的鳃丝较长;指名亚种扁平上皮细胞形态以不规则椭圆形为主,鳃丝表面有黏液细胞,其上分布的氯细胞数量多于甘子河亚种,而甘子河亚种扁平上皮细胞的形态以六边形为主,鳃丝表皮未观察到黏液细胞。由此推测,青海湖裸鲤两亚种鳃形态的差异与其食性和栖息环境相适应。     

青藏高原东北部祁连圆柏径向生长对不同类型干旱的响应

为研究祁连圆柏径向生长对不同时期(生长季前2—4月和生长季5—7月)气候因子的响应及面对不同类型(高温、缺水、高温+缺水)干旱事件的弹性(抵抗力和恢复力)变化,利用青藏高原东北部17个采样点的祁连圆柏树轮宽度资料,分析径向生长与不同时期气候因子的相关性,探究高低海拔祁连圆柏面对各类干旱事件的弹性差异。结果表明:祁连圆柏径向生长与干旱指数呈显著正相关,与生长季温度呈负相关(P<0.1)。祁连圆柏面对不同时期干旱事件的弹性存在显著差异,生长季前发生的干旱事件中,低海拔圆柏的抵抗力比高海拔增高2.3%,恢复力降低25.1%;生长季干旱事件中,低海拔圆柏的抵抗力比高海拔降低23.7%,恢复力增高107.1%。祁连圆柏面对缺水型干旱时恢复力更强,均值达到1.68,而面对高温型干旱时祁连圆柏的抵抗力更强,均值达到1.43。未来我国西部高山祁连圆柏,尤其是处于低海拔区的,其径向生长受到全球变暖造成的极端干旱事件的影响会更加显著。     

青海湖地区普氏原羚阿坝革蜱感染状况和防治对策

本文对青海湖地区6只死亡普氏原羚(Procapra przewalskii)携带的蜱虫进行了鉴别和统计,发现普氏原羚均染有阿坝革蜱(Dermacentor abaensis),平均感染数量为14只,主要寄生于头、颈部和背腰部。根据普氏原羚的带虫和周边畜牧业状况,提出预防和减少普氏原羚寄生蜱虫的建议。     

青海布哈河上游地区同域分布的普氏原羚与藏原羚草青期的集群比较

2005年6—7月和9月,运用样线法研究了青海省天峻县布哈河上游同域分布的普氏原羚（Procapra przewalskii）和藏原羚（Procapra picticaudata）的集群行为。该地区的普氏原羚和藏原羚集群类型分为雌性群、雄性群、混合群及母子群。四种集群类型中,雄性群出现的频次均为最高（普氏原羚和藏原羚分别为4l％和50％）;其次为雌性群（普氏原羚和藏原羚分别为34％和30％）;再次为母子群和混合群。比较集群规模发现,除藏原羚母子群显著大于普氏原羚（P=0．015）外,两个种其余集群类型规模差异不显著。集群规模出现频次：单只出现的频次最高（普氏原羚和藏原羚分别为21．9％和18．7％）;2—8只,普氏原羚和藏原羚分别为62．6％和67．6％;大于9只,普氏原羚和藏原羚分别仅占15．5％和13．7％。另外,普氏原羚和藏原羚产羔后平均集群规模显著减小（普氏原羚,P=0．014;藏原羚,P=0．008）;在雄性群、混合群规模均较产羔前略有增大的情况下,雌性群的规模却显著减小（普氏原羚,P〈0．001;藏原羚,P=0．002）,成为普氏原羚和藏原羚产羔后集群规模变小的主要原因。布哈河上游同域分布的普氏原羚和藏原羚草青期的集群类型、集群规模相差不大。     

线粒体控制区在鱼类种内遗传分化中的意义

线粒体DNA（mtDNA）作为分子标记已被广泛应用于各物种系统发生的研究。mtDNA控制区序列（D-Loop）以其较高的突变积累对于研究物种种内的遗传分化具有重要价值。鱼类是脊椎动物中最原始但在种属数量上又最占优势的类群,其物种繁多,分布广泛,起源复杂,研究其系统发生历来是令人饶有兴趣的课题。D-Loop在研究鱼类种内遗传分化中具有多方面的重要意义。近年来,已有越来越多的研究工作将D-Loop作为分子标记来探讨各种鱼类的种内遗传分化,并且获得了许多有启发性的结果。青海湖是我国内陆最大的咸水湖,湖中主要鱼类为青海湖裸鲤（Gymnocypris przewalskii）,D-Loop分析初步结果显示青海湖及其周围河流中的裸鲤似乎没有新的种内遗传分化现象。      

Microsatellite DNA markers for three toad-headed lizard species (Phrynocephalus vlangalii, P. przewalskii and P. guttatus)

To assess the impact of natural landscapes on the population structure of lizards, 10 polymorphic microsatellite DNA markers were developed for the Qinghai toad-headed lizard, Phrynocephalus vlangalii. The number of alleles at these informative loci ranged from four to 28. The novel markers and those previously developed for Phrynocephalus przewalskii were cross-tested among three toad-headed lizard species P. vlangalii, P. przewalskii and P. guttatus. A high cross-utility rate of more than 58% was observed among these three species. These markers are expected to be useful tools for taxonomic considerations as well as population genetic analysis and future conservation management.     

Male infanticide and paternity analyses in a socially natural herd of Przewalski's horses: Sexual selection?

The sexual selection hypothesis explains infanticide by males in many mammals. In our 11-year study, we investigated this hypothesis in a herd of Przewalski's horses where we had witnessed infanticidal attacks. Infanticide was highly conditional and not simply linked to takeovers. Attacks occurred in only five of 39 cases following a takeover, and DNA paternity revealed that, although infanticidal stallions were not the genetic fathers in four cases out of five, stallions present at birth did not significantly attempt to kill unrelated foals. Infanticide did not reduce birth intervals; only in one case out of five was the infanticidal stallion, the father of the next foal; mothers whose foals were attacked subsequently avoided associating with infanticidal stallions. Therefore, evidence for the sexual selection hypothesis was weak. The “human disturbance” hypothesis received some support, as only zoo bred stallions which grew up in unnatural social groups attacked foals of mares which were pregnant during takeovers.