中国岩黄耆属(豆科)种皮纹饰及其系统学意义

利用扫描电镜观察了国产岩黄耆属（Hedysarum L.）18个种（含3个居群）的种皮纹饰。结果表明：岩黄耆属种皮纹饰性状在种的划分上具有重要的分类学意义。依据种皮纹饰特性,大致分为光滑型和粗糙型2大类型以及断棱状、嚼烂状、龟纹状、网纹状与细网状5个亚型。依据其划分的类型及亚型,种皮纹饰呈现出从断棱状、细网状到光滑状的演化趋势,从而阐明了种皮纹饰在岩黄耆属系统演化上的重要意义。     

中国岩黄耆属一新种

多年生草本,高9—15cm。根直伸,暗褐色,直径8—10mm。茎短缩,不明显。叶奇数羽状,托叶合生,淡褐色;小叶2—3对,卵圆形,长15—24mm,宽10—15mm,顶生小叶较大,长可达30mm,宽20mm,先端钝圆,两面密被绢状毛,上面绿色,下面银白色。总状花序,具短于叶的总梗,有花6—20朵;花序轴密被贴生的绒毛;苞片长圆形;小花梗长约1mm,稍短于苞片;花萼钟状,萼齿较筒部长2—4倍,披针状钴形,密被贴生的毛;花冠淡紫色;旗瓣宽倒卵形,长9—10mm,先端微凹,基部急剧缢缩成很短的瓣柄;翼辦短,约4 mm长,瓣片长圆形,基部有短耳,具长约1 mm的瓣柄;龙骨辦长于旗瓣,约14—16mm长,瓣片近斜三角形,基部有耳,瓣柄很短;子     

国产黄耆属簇毛黄耆亚属花粉形态及其系统学意义

观察了国产黄耆属簇毛黄耆亚属6组12种植物的花粉形态。这些花粉的外壁表面纹饰可分为网状纹饰,穿孔或小沟渠状,以及穴网状纹饰3种类型。所有种类都具三孔沟的萌发孔,根据内孔明显与否可分为两类。虽然萌发孔类型与分组并没有严格的对应关系,但综合一些花粉特征,仍然发现6个组间花粉形态差异较为明显,与一般的形态差异有一定的对应性。特别是Sect．Robusti比较特殊,根据花粉大小等特征,推测它和Sect.Phyllolobium等有可能是本亚属的原始类群。Sect.Sesbanella的两个近缘种Astragalus heydei和A.hendersonii,花粉形态却很有区别。Sect.Bibacteola种类较多,有24种,花粉形态呈多样性。总之,花粉形态在簇毛亚属中具有一定的系统学意义。     

中国黄耆属簇毛黄耆亚属的叶表皮特征及其系统学意义

在光学显微镜和扫描电镜下,观察了国产黄耆属簇毛黄耆亚属16种1变种的叶表皮特征。结果表明,气孔器在各种植物的上、下表皮均有分布,多为无规则型,也有不等细胞型;叶表皮细胞形状有不规则形与多边形,表皮细胞垂周壁有平直、浅波状、波状或深波状。叶表皮细胞形状与垂周壁的式样可以分为四种类型,这四种类型与亚属的分组有一定的对应关系。在扫描电镜下可见表皮细胞上有角质层,气孔下陷,气孔的外拱盖及其内缘特征在亚属内都比较一致。表皮细胞角质层的纹饰在个别类群中有一定的变异,对种类的鉴定有一定的意义。     

黄耆属簇毛黄耆亚属系统学研究

簇毛黄耆亚属以其柱头上具簇毛等形态特征与黄耆属其它类群相区别,约含49种（变种）。主要分布在青藏高原及其邻近地区,绝大多数种类分布于横断山区。本文基于形态特征和分支系统学方法分析亚属内种系发生关系。结果表明,49种（变种）可分为9组。其中双小苞组Sect.Bibracteolati含种类最多,是一个并系类群。借助于分支图,分析了6个较重要的鉴定特征的演化,习性,茎的着生方式,小苞片,果实形态,柱头具簇毛,果实膨胀状况等。最后作出了这个亚属的一个分类纲要。     

岩黄耆属系统分类研究进展

回顾了自Fedtschenko以来在岩黄耆属分类、区系地理和系统发育方面所取得的成就,根据目前的研究现状,提出了岩黄耆属今后研究的重点和方向。     

中国黄耆属(豆科)丁字毛类群2新种——额尔齐斯黄耆和沙地黄耆

描述了产于中国新疆的黄耆属（Astragalus）丁字毛类群2新种,即额尔齐斯黄耆（Astragalus eerqisiensis Z.Y.Chang,L. R. Xu ＆ D.Podlech）和沙地黄耆（A.shadiensis L. R. Xu,Z.Y.Chang ＆ D.Podlech）.其中,额尔齐斯黄耆仅见于新疆布尔津县的额尔齐斯河流域,与哈巴河黄耆（A.habaheensis）近缘,区别在于前者小叶菱形、倒卵形或椭圆形,长15～25（30）mm,宽（3）7～12（15）mm,旗瓣长20～22（25）mm,翼瓣顶端2裂;沙地黄耆产于新疆托克逊县东北部,散生于沙地荒漠,形态上与变异黄耆（A. variabilis Bunge ex Maxim.）接近,区别在于小叶5～7（9）枚而非11～19枚,旗瓣在中部收缩,植株全体被灰色毛而呈灰色.2新种均系中国特有种,其中额尔齐斯黄耆隶属于乌拉尔组（A. Sect.Helmia Bunge）,沙地黄耆隶属于旱生组[A. Sect.Craccina（Stev.）Bunge].     

昆仑岩黄耆(豆科)在中国的分布

报道了豆科Leguminosae昆仑岩黄耆Hedysarum krassnovii B．Fedtsch．在中国的分布。昆仑岩黄耆与近缘种红花岩黄耆H.multijugum Maxim.形态易混淆,但以其小叶3-9×3-7mm;旗瓣倒卵形,顶端凹陷约2mm深;翼瓣狭披针形;龙骨瓣近半圆形或矩圆形;花萼二唇彤;荚果具1-2节荚等性状易于区分。另外,此二种的物候期、生境及地理分布亦有区别。     

中国黄耆属一新种

中国黄耆属一新种朱相云,陈家瑞（中国科学院植物研究所,北京１０００－９３）ＡＮＥＷＳＰＥＣＩＥＳＯＦＡＳＴＲＡＧＡＬＵＳ（ＬＥＧＵＭＩＮＯＳＡＥ）ＦＲＯＭＣＨＩＮＡ￥ＺｈｕＸｉａｎｇｙｕｎａｎｄＣｈｅｎＣｈｉａｒｕｉ（ＩｎｓｔｉｔｕｔｅｏｆＢｏｔａｎ...     

中国黄耆属一新分类群

昭陵黄耆 (新种) 图 1 Astragalus (subgen. Cercidothrix sect. Traehyeeris) zhaolingicus K. T. Fu, sp. nov. Species A. galactiti Pall. affinis, sed plantis humilioribus; foliolis paucioribus (11-15) parvioribusque, 3-5.5 mm longis, 1-1.5 mm latis; breviter inflorescentiis 3-7-floris; bracteis margine nonnisi     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.