永瓣藤的地理分布及其种群空间格局

应用Ｇｒｅｉｇ－Ｓｍｉｔｈ邻接格子取样法,研究了我国珍稀植物永瓣藤（ＭｏｎｉｍｏｐｅｔａｌｕｎｃｈｉｎｅｎｓｅＲｅｈｄ）,的地理分布和种群空间格局及其形成机制,分析了其克隆生长格局和生态适应对策,研究结果表明,永瓣藤的分布区域狭窄,其种群空间格局为集群型,克隆生长格避为游击式稀疏形式样式,这与其生物学特性和种群生态适应的对策密切相关。     

八角枫挥发油化学成分研究

八角栎是八角枫科八角枫属药用植物,分布较广。用气相色谱／质谱／计算机联用技术（ＧＣ／ＭＳ／ＤＳ）分析了水蒸气蒸馏得到的八角枫挥发油,鉴定出５９种化学成分,其主要成分为：１,８－桉叶素（４３．３２５％）、β－侧然（１０．７１３％）、丁香酚甲醚（７．０８８）、α－松油醇（７．０１７％）、α－蒎烯（５．８３０％）等５种化合物。被鉴定的５９种成分,共占挥发油总量的９７．０４％。     

The Relationship Between the Nariations of Fruit-Bearing Organic Characters in Natural Aneurolepidium chinense Population and the Climatic Factors in the Songnen Plain of China

Based on eight years continuous observation and measurement on the ways and intensity of utilization of three fixed plots of the meadow of natural Aneurolepidium chinense in the Songnen Plain of China at definite stage of annual growth season the quantitative analysis on the relationship between the variations of fruit-bearing organic characters of A. chinense population and the climatic factors was investigated. Change of climate was one of the comprehensive factors which led to the variations of fruit-bearing organic characters of the population in different plots, but variations on the characters of the population among the plots and on the degree of correlation or functional relationships between the character and the climatic factor in different stages were only caused by the ways and intensity utilization. The characters of the spike organ were more affected by climatic factors in the stage of growth and development of the winterness plants of the population. There were universal ecological effects of time lap in the climatic factors.     

Chemical constituents from Bupleurum chinese and their chemotaxonomic significance

A phytochemical investigation of the roots of Bupleurum chinese DC. led to the isolation of eighteen compounds, including three chromones (1–3), seven flavonoids (4–10), one dihydrochalcone (11), two phenylpropanoid glycosides (12–13), one lignan (14), three sterols (15–17) and one stilbenoid (18). Their structures were elucidated on the basis of NMR spectroscopic analysis and comparison with literature data. Compounds 6–7, 11–14 and 18 were firstly reported from the genus Bupleurum and the family Apiaceae. Moreover, the chemotaxonomic value of the isolates was also discussed.     

中国鹅掌楸双受精和胚胎发生的细胞形态学观察

本文运用常规手段观察了中国鹅掌楸的双受精和胚胎发生,并探讨了其致濒的原因。中国鹅掌楸的卵细胞极性化不明显,中央细胞的两极核直至受精才与精核同时融合,受精为有丝分裂前型;原始细胞型胚乳,胚胎发生为柳叶菜型。     

鹅掌楸在中国的自然分布及其特点

鹅掌楸（Ｌｉｒｉｏｄｅｎｄｒｏｎｃｈｉｎｅｎｓｅ（Ｈｅｍｓｌ．）Ｓａｒｇ．）星散分布于长江流域以南海拔４５０～１８００ｍ阔叶林中。依其自然地理区域,鹅掌楸在我国西部,从北由大巴山,经武陵山、大娄山,伸向云贵高原东部,形成一条东北．西南走向分布带,在东部和中南部,有５个各自以中、低山为中心,被平原相间隔的“岛”状分布。较大种群多分布在我国西部。与北美鹅掌楸（Ｌ．ｔｕｌｉｐｉｆｅｒａＬ．）在北美洲的分布相比,鹅掌楸为星散间断分布,天然更新不良,在自然群落中多为偶见种。中国东部和西部鹅掌楸在形态上存在较明显的差别,西部种群在花被片颜色,叶片裂片变化及同工酶等方面表现出与北美鹅掌楸有更多的相似特性。因而推论,现存鹅掌楸属的这两个对应种,在地史上是通过欧洲及大西洋陆桥建立联系的     

藠头大小孢子的发生及雌雄配子体败育的细胞学研究

对栽培Ｊｉａｏ头４个品种大小孢子发生和雌雄配子体发育的细胞学观察表明,Ｊｉａｏ头小孢子细胞减数分裂过程基本正常,四分体左右对称或四面体体型,部分单核小孢子解体。散粉时,多数花粉粒空瘪,无萌发沟;部分花粉粒人单核或二核;极少数花粉粒具有生殖核和营养核。共 粒生活力低或无,无花粉管萌发。囊发育属葱型,部分能发育形成四核胚囊,大部分发育异常,出现二 核至五核胚囊,未观察到正常七细胞八核胚囊的形成。结果表     

鹅掌楸致濒的生态因素研究

鹅掌楸（Liriodendronchinense（Hemsl．）Sarg．）为古老残遗植物,该属植物在第三纪曾广布于北半球。由于第四纪冰川的压力,现存中国鹅掌楸局限星散分布于被称作“避难所”的长江流域以南亚热带山地,其种群大小和结构,受到与其共存的优势树种的竞争压力及人为干扰等多方面因素影响。目前天然分布的鹅掌楸,其种群规模小,在原生境中往往种子饱满率偏低,尤其是位于分布区东部的种群,正处于非适宜的“濒危生境”中。如果物种陷入了因地质历史变化、种间竞争或其他灾难引起的“濒危生境”中,运用迁地保护手段,可有效地保护该物种。     

火烧和放牧影响下羊草草地微气候的比较研究

对羊草草地火烧、未火烧、过度放牧和禁牧区植物群落温度、土壤温度、土壤湿度、大气温度、相对湿度进行了测定．结果表明,白天火烧区群落温度比未火烧区低２．５～５℃,而夜晚则高于未火烧区０．１～１℃．白天火烧区土壤温度比未火烧区高５～７,５℃,夜晚为１～２．５℃．过牧区群落温度与禁牧区差异不显著,但过牧区土壤温度基本高于禁牧区,土壤湿度小于禁牧区．同一区中,白天群落温度变化为低处大于高处,夜晚则相反,而白天土壤温度为表层大于深层,夜晚则基本为深层大于表层．     

羊草种群种子生产的初步研究

 本文报道了国产优良牧草——羊草,在不同人为干扰的环境条件下,种群种子生产数量性状变化的若干规律。种群密度是成穗率的限制因素之一,在平均为604.7株／m2中等密度的数年割草场上,成穗率随密度增加呈幂函数y=dx-b形式下降,而在平均为1604.9株／m2高密度的长期连续割草场上,成穗率随密度增加呈直线y=a-bx形式下降。种子发芽率与千粒重呈显著正相关(r＝0.9768**)。放牧对成穗有不良影响,但对籽粒的干物质积累过程有一定的促进作用。长期连续割草对种群生殖生长的整个过程均不利,停刈后,自然恢复的速度缓慢。