洋葱花药发育过程中的细胞化学研究(简报)

高等植物花药结构复杂,其发育更是一个迅速、多变的过程,如小孢子母细胞减数分裂期间的细胞质改组、胼胝质壁的形成与降解、大液泡的形成与消失、花粉内外壁的形成、绒毡层细胞的降解、营养物质的积累与转化等。除了上述花药组成细胞的形态和结构发生明显变化外。花药发育的另一个显著特点是以花粉为中心的营养物质单向运输和转化,尤其是小孢子有丝分裂形成二胞花粉后开始积累大量的营养储存物以供成熟花粉萌发时利用。     

中国湖南杜鹃花科杜鹃花属一新种——天门山杜鹃

报道了中国湖南天门山国家森林公园内发现的杜鹃花科Ericaceae杜鹃花属Rhododendron一新种——天门山杜鹃R．tianmenshanense C．L．Peng＆L．H．Yan。该种与雪山杜鹃R．aganniphum Balf.f.＆K．Ward近似,但以叶为长圆状椭圆形,叶背具两层毛被,上层为银白色短绒毛,下层为紧贴的鳞片状细毛,总花梗和花梗具密而短的腺毛,花常5朵组成总状花序而不同。该种隶属常绿杜鹃组大理杜鹃亚组sect．Ponticum subsect.Talienisa。     

Contributions of nutrition science to anthropological research.

Certain investigations of nutrition scientists have demonstrated the effects of cultural practices on nutrient intake. Anthropologists, too, have studied diets and food-related behavior, although until recently their interests infrequently included nutritional status. In the last decade, nutrition scientists' research helped stimulate the creation of an interdisciplinary specialty, nutritional anthropology, that combines techniques from both nutritional and anthropological science in the study of food use in relation to health. Practitioners of this expanding field make useful contributions to research in human nutrition through study of social aspects of the diet of individuals and groups. Their assistance can be particularly helpful in studies of populations in developing countries and of ethnic minorities in this country. Certain unanswered nutritional questions, which might more readily be solved by the combined efforts of nutritionists and nutritional anthropologists than by either professional alone, are presented.     

胡葱与洋葱、葱过氧化物酶同工酶研究及聚类分析

本文对胡葱与洋葱、葱的功能叶过氧化物酶同工酶电泳图谱分析和聚类分析表明：这三个种及葱的3个交种闻的亲缘关系被区分开来;胡葱与洋葱的亲缘关系比胡葱与大葱的亲缘关系更近。     

枸杞花药发育过程中脂滴和淀粉粒的分布特征

宁夏枸杞(Lycium barbarurn L．)花药发育过程中,淀粉粒和脂滴两种营养物质的积累和分布具有一定的特点：在造孢细胞时期,药隔薄壁细胞,表皮和药室内壁细胞中开始积累淀粉粒,而造孢细胞、绒毡层细胞和中层细胞中则没有淀粉粒。在四分体时期,绒毡层细胞开始积累脂滴并且数量逐渐增加。到小孢子晚期,绒毡层细胞降解,内含脂滴流入药室中。在小孢子发育过程中既没有淀粉粒也没有脂滴积累,直到二胞花粉的大液泡消失后花粉粒中才开始积累脂滴,然后又开始出现淀粉粒。枸杞成熟花粉中的营养储存物是脂滴和淀粉粒。     

红花玉兰等5个玉兰种花粉形态观察及分类学意义

通过对红花玉兰（Magnolia wufengensis L. Y. Ma et L. R. Wang）等5个玉兰种的花粉的光学显微镜和扫描电子显微镜观察拍照,测量光学显微镜下的花粉大小并对其进行统计学分析。结果表明：光学显微镜下,木兰属5个种的花粉均呈现椭圆形或近圆形,各种之间大小、形状方面有较大差异,种内部也存在不同程度的差异;扫描电子显微镜下,各种花粉均为舟形,且具有闭合、长及两端的远极萌发单沟等一致特征,花粉表面纹饰、突起等特征在种内部比较稳定,不同种之间差异明显,可以为木兰属植物种的划分提供比较准确的依据。     

提取蕨类植物蜈蚣草总RNA的一种有效方法

介绍了一种提取蕨类植物蜈蚣草(Pteris vittata L.)总RNA的有效方法.由于蜈蚣草富含多酚和多糖,用普通的RNA提取方法很难获得高质量的RNA.本方法通过优化提取缓冲液的条件来抑制多酚氧化,并利用RNA与多酚、多糖在不同浓度的2-丁氧乙醇中溶解度不同的特性来去除多酚和多糖.本方法简便、快速,所提取的RNA质量较高,可直接用于cDNA合成、cDNA文库的构建以及RACE等分子生物学操作.     

药用寄生植物菟丝子属,列当属和无根藤属氨基酸的分析

本文测定了菟丝子属、列当属和无根藤属某些种的种子和植株氨基酸的种类组成和含量。结果表明,3个属种子和植株氨基酸均在15种以上,且含量丰富,特别是必需氨基酸的含量较高。文中讨论了氨基酸的药用和在种子鉴定与化学分类上的作用,探讨了开发应用的前景。     

硝态氮对小白菜铬污染毒性的调控作用

通过盆栽和水培试验,探讨了硝态氮对小白菜铬污染毒性的调控作用。结果表明:外源Cr6 对小白菜铬吸收和积累具有明显的促进效应,抑制了小白菜对铁养分的吸收并降低了小白菜的硝酸还原酶活性;硝态氮可有效缓减Cr6 对小白菜吸收铁和硝酸还原酶活性的抑制作用,促进小白菜碳氮代谢和Vc的生物合成,并刺激小白菜生长。在相同铬污染条件下,土壤硝态氮的增加促进了外源Cr6 向有机态转化,且硝态氮有协同强化小白菜吸收Cr6 的效应。表明硝态氮在促进小白菜生长的同时,也促进了小白菜对Cr6 的吸收,提高了小白菜的铬累积水平。     

中国滇西天南星科一新种——保山犁头尖

描述了天南星科Araceae南星族Areae犁头尖属Tiphonium Schoa一新种——保山犁头尖Typhonium baoshanense Z.L.Dao ＆ H.Li,它的叶形和佛焰苞形态与犁头尖T.blumei Nicolson ＆ Sivadasan相似,但附属器下部,雄花序之上,有1-2轮不育雄花（退化雄蕊）,雌花序圆锥形,附属器基部截形和佛焰焰苞檐部狭窄而易于区别。同域分布的犁头尖染色体数目为2n=52,本种染色体数目为2n=10,为天南星科的最低染色体基数。     

Molecular phylogeny supports the morphologically based taxonomic transfer of the “medicagoid”Trigonella species to the genus Medicago L.

 The taxonomic transfer of the 23 Trigonella species previously known as medicagoids to the genus Medicago L. is reanalyzed on the basis of a molecular phylogenetic approach. The internal and external transcribed spacers of 53 Medicago species s. str. and 10 of the 23 medicagoid species were sequenced. Both maximum parsimony or maximum likelihood criteria joined medicagoid species more confidently with Medicago rather than with Trigonella. The basal position of the medicagoid species within the genus Medicago, together with morphologically atypical Medicago species (such as M. radiata and M. platycarpa), raised the question of the expediency to define a new genus and is discussed, relatively to the support of each clade. Using criteria of monophyly and support, it was concluded that the medicagoids are better joined in Medicago rather than placed in a new genus. Received February 6, 2001 Accepted July 17, 2001     

中国山茶属(山茶科)一新变种——长蕊西南山茶

描述了山茶科Theaceae一个新变种--长蕊西南山茶Camellia pitardii var. longistaminata J. L. Liu &; Q. Luo。这一新变种与原变种西南山茶Camellia pitardii Cohen-Stuart的区别是花瓣较大, 长4.4-6.2(-8) cm, 宽3.1-4.4 cm; 雄蕊花丝特长, 外轮花丝长4.2-5.1 cm, 在中部或中上部合生, 内轮花丝长2.5-3 cm, 花丝管长2.3-2.8 cm。     

金边黄杨与大叶黄杨光合特性的比较

在田间条件下,比较金边黄杨与大叶黄杨光合生理特性的结果表明：（1）金边黄杨的叶绿素含量极显著低于大叶黄杨,类胡萝卜素和花色素苷含量无显著差异;（2）金边黄杨的光合能力显著低于大叶黄杨,表现量子效率、羧化效率分别为大叶黄杨的54％和50％;（3）二者的净光合速率日变化均为单峰曲线,金边黄杨净光合速率和蒸腾速率日积分值分别为大叶黄杨的60％和75％。     

离子注入加速棉花陆海杂种农艺性状遗传稳定性的研究

利用３０ＫｅＶ的Ｎ＾＋离子束注入陆地棉和海岛棉的花粉及杂交Ｆ１种子,分析了杂种后代农艺性状遗传稳定性的变化。结果表明：Ｎ＾＋离子辐照能显著地加速杂种后代的遗传稳定性,Ｆ４Ｍ４代性状稳定度可达９０％左右。Ｆ１种子辐照后代农艺性状多偏向陆地棉,而且花粉辐照杂交后代农艺性状表现出偏母遗传。同时以＾６０Ｃｏγ射线效应为对照,初步探讨了Ｎ＾＋离主入加速遗传稳定的机制。     

明亮熊蜂和意大利蜜蜂在温室桃园的访花行为和传粉生态学比较

2004—2006年连续3年应用明亮熊蜂和意大利蜜蜂在北京为温室桃园传粉,对其访花行为和传粉生态学进行研究.结果表明：两种蜂都可以替代人工掸花为温室桃园提供有效的传粉服务.两种蜂的访花行为和传粉效果不同,明亮熊蜂偏爱于采集花粉,主要以震动翅膀的方式来使花粉释放和传播,而意大利蜜蜂偏爱于采集花蜜,主要以身体接触的方式来粘附和传播花粉;明亮熊蜂的活动起点温度低、日工作时间长、访花速度快,在低温条件下比意大利蜜蜂的传粉效果好;意大利蜜蜂的趋光性强,飞撞温室塑料薄膜的现象严重,受温度和光照条件的影响较大,对温室环境的适应性较差.     

祁门过路黄和过路黄核型的比较研究

报道了祁门过路黄和过路黄的核型。前者核型公式为2n=2x=24=6m 6sin 6st 6t,为首次报道;后者核型公式为2n=2x=24=2m 4sm 6st 12t。与前人报道一致．并进一步对二者的核型进行比较分析。根据核型和外部形态特征的综合分析,祁门过路黄和过路黄的差异水平已明显超过种内变异水平,故将祁门过路黄独立出来,另立新种,是比较恰当的。     

兴安、长白及华北落叶松RAPD分子标记的物种特异性鉴定

以中国北方地区主要乡土落叶松树种兴安落叶松（Larix gmelini）、长白落叶松（L.olgensis）和华北落叶松（L．principis—rupprechtii）的针叶及种子胚乳为研究材料,采用RAPD分子标记技术对3种落叶松进行不同物种的种间鉴别。结果表明,通过引物筛选得到了4个可以鉴别3种落叶松的RAPD引物,其中有2个引物在落叶松针叶和种子胚乳基因组中都扩增出相同的条带。引物OPB-11在兴安和长白落叶松基因组DNA中1500bp处扩增出特异条带,而在华北落叶松中没有：引物OPX-14在兴安落叶松基因组DNA中1200bp处扩增出特异条带,而在长白落叶松中没有：还有2个引物可分别作为3种落叶松苗木和种子鉴别的辅助标记。本研究从分子水平上为落叶松的种间鉴别提供了新的鉴定方法。     

Ontogenetic variation in response to temperature change in the control of seed dormancy of Rumex obtusifolius L. and Rumex crispus L.

Abstract After the onset of imbibition, the dormant seeds of Rumex obtusifolius and R. crispus are stimulated to germinate by a change from an initial low temperature to a warmer temperature for a relatively brief period: the warmer that temperature the shorter is the optimum period spent at it, and this optimum value is unaffected by the initial temperature. The optimum period is more critical in R. crispus than in R. obtusifolius (about 1 h and 2.5 to 4 h, respectively, for a warmer temperature of 35°C in the dark); in the light the length of the period at the warmer temperature is less critical in both species. The sensitivity of the seeds to the change to the warmer temperature increases with time from the start of imbibition at a rate which is positively related to the initial temperature. In R. obtusifolius maximum sensitivity was typically reached after 3 to 5 d when the initial temperature was 20°C and then remained constant, or declined only slightly, over the period investigated (10 d). At the same initial temperature, however, R. crispus showed a cyclical pattern of sensitivity with peaks occurring at 3–4 d intervals from the start of imbibition.