普氏野马繁殖群在组建和放归初期的争斗行为与社群等级建立

2007年5月下旬至6月下旬,针对新组群并放归于卡拉麦里有蹄类保护区第二放归点的普氏野马(Equus przewalskii)繁殖群,采用焦点动物取样法和全事件记录法,观测记录了组群和放归初期繁殖群内个体间的争斗行为(攻击行为和屈服行为),以优势指数法确定繁殖群内的个体等级序列。结果表明,新组群内个体的年龄与攻击行为发出次数不存在显著的相关性(r=0.60,t=1.62,rr0.05),攻击与屈服行为次数也无显著的相关性(r=0.56,t=1.41,rr0.05)。各个体之间从最初组群到野放争斗行为日趋减少,社群等级逐渐建立并趋于稳定。     

青海湖裸鲤体外肝胰细胞原代与传代培养

采用组织块移植培养技术,分别用DMEM和RPM11640培养基对青海湖裸鲤肝胰组织细胞进行原代培养。培养48h组织块周围有细胞迁出,并形成生长晕。培养一周可形成单层细胞。对原代培养的单层细胞用胰蛋白酶-EDTA消化后,传代培养至第四代。确立青海湖裸鲤肝胰细胞培养条件为：培养基为DMEM,培养温度为27℃,pH值为7．0—7．5,原代培养血清浓度为20％,传代培养的血清浓度为10％,无需通入CO2和添加细胞生长因子。     

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。      

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。     

Physiological responses of Populus przewalskii to oxidative burst caused by drought stress

We measured dry matter accumulation and allocation to the roots, leaf gas exchange, chlorophyll fluorescence, antioxidant enzymes, and ABA and polyamine (PA) contents in Populus przewalskii under three different watering regimes (100, 50, and 25% of the field capacity) to investigate the morphological and physiological responses to water deficit in woody plants. The results showed that drought stress retarded P. przewalskii as evident from a decreased biomass accumulation and the reduced increment of shoot height and basal diameter. Drought stress also affected the biomass partition by higher biomass allocated to the root systems for water uptake. The contents of ABA and PAs especially were increased under stressful conditions. Drought stress caused oxidative burst indicated by the accumulation of peroxide (H₂O₂), and fluorimetric detection also confirmed the increased accumulation of H₂O₂. The antioxidant enzymes, including superoxide dimutase, peroxidase, ascorbate peroxidase, and reductase, were activated to bring the reactive oxygen species to their homeostasis; however, oxidative damages to lipids, proteins, and membranes were significantly manifested by the increase in total carbonyl (C=O) and electric conductance (EC).     

青海湖地区普氏原羚的种群结构

普氏原羚是中国的特有动物。 1986年在青海湖地区仅发现 35 0只普氏原羚 ,分布于鸟岛、湖东 克图和元者 3个种群之中。 1996～ 1998年 7月至 8月 ,我们沿设定的 10条样线对青海湖地区的普氏原羚进行了考察。调查样线总长度为 37 5 5km。观察记录距样线两侧 10 0m以内普氏原羚足迹链和狼足迹链、粪堆和尿迹。同时记录观察样线两侧 6 0 0m以内的普氏原羚个体 ,记录群体大小、性别和年龄 ,然后 ,计算单位样带面积上普氏原羚和狼的密度。 1997年湖东 克图种群雄羚占 2 9%、雌羚占 5 0 %和幼羚占 2 1% ;元者种群雄羚占 2 9%、雌羚占 43%和幼羚占 2 7%。狼捕食是 1997年湖东 克图种群数量下降的主要原因。在湖东 克图沙漠中 ,1996年普氏原羚群体大小为 9 0± 6 9只 (平均数±方差 ) ,密度为 3 19± 3 5 9只 /km2 ,而 1997年为 4 2± 3 9只 /km2 ,密度为 1 14± 1 0 9只 /km2 。 1997年冬季猎狼后 ,湖东 克图种群数量回升到 2 14± 3 13只 /km2 ,幼羚占群体的2 7%。     

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。     

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.     

Dietary Overlap of Przewalski's Gazelle,Tibetan Gazelle,and Tibetan Sheep on the Qinghai-Tibet Plateau

Abstract: We studied food composition and overlap among sympatric Przewalski's gazelle (Procapra przewalskii), Tibetan gazelle (P. picticaudata), and Tibetan domestic sheep (Ovis aries) in the Upper Buha River, Qinghai-Tibet Plateau, using microscopic fecal analysis. The 2 gazelles forage mainly on plants from Leguminosae and Compositae families and domestic sheep feed mainly on Gramineae and Cyperaceae. The dietary overlap index between the 2 gazelles and Tibetan domestic sheep increased from 0.43 to 0.58 during the plant-growing period to 0.76–0.77 during the plant-withering period, which indicated competition for foods intensified during the food-limited season. Although the 2 gazelle ate similar diets, they might avoid food competition by occupying different foraging areas. We suggest reducing numbers of overwintering Tibetan domestic sheep on pastures to lessen survival pressure on the endangered gazelles during winters.