镧与钙的关系及对根系生理的影响

本研究通过探讨毛乌素沙地主要早生植物和中生植物的水分关系。对“早生植物”的概念作了进一步的分析的阐述，探讨了蒸腾作用、光合作用的气乳调节与植物叶片水分平衡的相互关系，并提出了以蒸腾“午体”为基础的关于划分植物水分生态类型的新概念。上述问题的探讨可作为对中国毛鸟素沙化化草地植物环境系统优化模式的水平衡假说的难证。探讨了为合理确定在研究地区种草造林的最佳密度所需进一步研究的内容：水分亏缺对植物量累积的抑制作用。并对该地区主要植物种的季节蒸腾耗水量作了估算。研究了依赖于主导环境因子的沙生植物蒸腾速率的回归模型。得出结论认为：对于蒸腾速率和叶面积指数，建立多元非线性回归可以取得较好结果。最后，对几个重要的蒸散预测模型和土壤水分运动的物理模型进行了评述，并探讨了这些模型对于干旱区蒸散预测研究的可行性，作为本研究的未来探讨的课题。

海南黄牛和徐闻黄牛线粒体DNA的多态性及其品种分化关系

以14种限制性内切酶分析来自海南岛的海南黄牛和雷州半岛的徐闻黄牛的线粒体DNA限制性片段长度多态性(mtDNA RFLP)。结果只有一种限制性内切酶(sal I)在海南黄牛中检测到多态性, 且其中的C型(15.0, 1.3)尚未见报道。结果还显示, 两个品种6个个体的mtDNA基因单倍型全部表现为A型, 即瘤牛的血统, 并表明两个品种的亲缘关系很近。

黑叶猴和灰叶猴的线粒体DNA限制性片段长度多态研究

以15种限制性内切酶分析黑叶猴和灰叶猴种内及种间m+DNA多态。从各个样品中分别检出了41—50个酶切位点。综合15种限制性内切酶的酶切类型, 在2只黑叶猴和2只灰叶猴中分别检出了两种限制性类型, 并与其4个地理来源相对应。结合恒河猴和红面猴的资料, 构建了4种猴科动物的分子系统树。结果表明, 黑叶猴和灰叶猴种的分歧分别始于30和35万年以前, 两种叶猴的分离始于190万年以前, 猴亚科和疣猴亚科的分离应早于1100万年。叶猴属在中国的 扩散不是很晚才发生的。图2表2参15

Genetic diversity and population history of golden monkeys (Rhinopithecus roxellana)

Golden monkey (Rhinopithecus roxellana), namely the snub-nosed monkey, is a well-known endangered primate, which distributes only in the central part of mainland China. As an effort to understand the current genetic status as well as population history of this species, we collected a sample of 32 individuals from four different regions, which cover the major habitat of this species. Forty-four allozyme loci were surveyed in our study by allozyme electrophoresis, none of which was found to be polymorphic. The void of polymorphism compared with that of other nonhuman primates is surprising particularly considering that the current population size is many times larger than that of some other endangered species. Since many independent loci are surveyed in this Study, the most plausible explanation for our observation is that the population has experienced a recent bottleneck. We used a coalescent approach to explore various scenarios of population bottleneck and concluded that the most recent bottleneck could have happened within the last 15,000 years. Moreover, the proposed simulation approach could be useful to researchers who need to analyze the non- or low-polymorphism data.

测定细胞存活和增殖的MTT方法的建立

以Raji细胞为对象, 比较了12种不同的MTT甲ti溶解缓冲液。结果表明, 20%SDS-50%DMF效果最好, 溶解力强, 溶解甲ti所需时间短, 背景低, OD值高, 不会引起培养基中小牛血清的絮状沉淀。其溶解的甲ti产物吸收峰在550—600nm之间。测定细胞范围为每孔500—400 000, 能满足生物学和医学研究中多种测定的需要。图3表1参12

Anti-HIV-1 activities of extracts from the medicinal plant Rhus chinensis

Rhus chinensis, a species used in folk medicine by Chinese native people, the anti-HIV-1 activities of the petroleum ether, ethyl acetate, butanol and aqueous extract of Rhus chinensis, named as RC-1, RC-2, RC-3 and RC-4, respectively, was evaluated. The