芦苇根尖体细胞的染色体数目和形态

本文研究了芦苇(Phragmites communis)幼苗根尖分生组织细胞的染色体数目和形态。其染色体数为2n=96。在有丝分裂中期染色体组中,染色体的大小逐渐地改变,按照染色体的大小和形态,96个染色体能被分成8个同源单倍体染色体组。每一组由11个中部着丝点染色体和1个亚中部着丝点染色体组成。     

常见动植物体细胞染色体数目

生物学杂志总第59期黝脚体缠晒瓣嚓坪鲜献动物名称染色体数目人黑猩猩猩猩大猩猩猿黑长臂猿称猴台湾猴恒河猴黑叶猴金丝猴水牛黄牛耗牛黑白花牛马驴骡山羊绵羊猪狗猫虎豹到币赤孤猪俐紫貂46484848485242424244444860605864、6662636O5438、4052、7838383838363838动物名称染色体数目棕熊亚洲象大熊猫小熊猫海豹河狸长须鲸兔穴兔(野生种)鹿东北梅花鹿赤屡小家鼠小白鼠大家鼠大白鼠褐家鼠中国田鼠田鼠仓鼠豚鼠碳袋鼠刺猾鸡火鸡鸭野鸽家鸽白鹭蝮蛇眼睛蛇银环蛇竹叶青蛇烙铁头蛇五步蛇晰蝎大壁虎水龟鳖杨子鳄青蛙林蛙牛蛙无斑雨蛙蟾蛛爪蟾嵘螟…     

芦苇细胞培养中的染色体稳定性及诱变效应

培养一年后的芦苇愈伤组织中,仍以80%的八倍体细胞占绝对优势。染色体数目变异范围在105—26之间。而 EMS 处理的愈伤组织与末经处理的愈伤组织相比较,明显地具有比较高的染色体数目变异和倍性变异。     

竹柏染色体数目和形态

本文对竹柏(Podocarpus nagi(Thb.)Zoll.et Moritz.ex Zoll.)的染色体组型进行了初步观察。观察结果:染色体数目2N=29;染色体长度变化在3.32—6.21微米之间;其相对长度的变动范围是5.29—9.90％;臂比表明有6对染色体具有中部着丝点,7对染色体具有近中部着丝点,其中有2个随体。     

芦苇细胞培养中的染色体稳定性及诱变效应

培养一年后的芦苇愈伤组织中,仍以80％的八倍体细胞占绝对优势。染色体数目变异范围在105—26之间。而EMS处理的愈伤组织与末经处理的愈伤组织相比较,明显地具有比较高的染色体数目变异和倍性变异。     

独尾草的染色体数目和核型

独尾草属(Eremurus M. Bieb)全世界约有20多种,主要分布于中亚及西亚的山地和平原沙漠地区。我国产4种,其中独尾草(E. chinensis Fedtsch. )主要分布于四川、云南和西藏,在甘肃南部的岷县、舟曲、武都、文县也有分布。其染色体数目和核型迄今未见报道,本文对采     

泡桐属植物染色体数目和形态的初步研究

本文报道了毛泡桐,白花泡桐和兰考泡桐的体细胞染色体数目均为2n=40。这与已报道的紫葳科大多数木本植物染色体数目是一致的,而与玄参科的大部分届不同。结合形态特征,认为将泡桐属归于紫葳科可能是更为合理的。并对白花泡桐和兰考泡桐的核型进行了初步分析。     

朱顶红染色体数目和核型

朱顶红是石蒜科朱顶红属植物。我们对它进行了核型分析,结果表明,它是一个三倍体种,核型公式为：２ｎ＝３ｘ＝３３＝１２ｍ＋９ｓｍ＋１２ｓｔ。     

崇明水仙根尖体细胞染色体的观察和核型分析

以崇明水仙(Narcissus tazetta L.var.chinensis Roem.)根尖体细胞为实验材料,对适宜于崇明水仙细胞学研究的前处理液和前处理时间进行了筛选,在此基础上,应用根尖压片法对重瓣花型和单瓣花型崇明水仙体细胞染色体数、核型及倍性进行了比较分析.结果显示:适宜的前处理液是对二氯苯饱和溶液,适宜的前处理时间为12 h.重瓣花型和单瓣花型崇明水仙的染色体核型差异较小,相同点为:不对称二型核型,染色体基数x=10,三倍体,体细胞染色体数2n=3x=30,第7号染色体的短臂具随体,核型均属于"3B"型,臂比大于2的染色体比率为90%.不同点为:重瓣花型的第7号和第8号染色体分别为sm和st型,单瓣花型的第7号和第8号染色体分别为st和sm型;前者的核型不对称系数(76.48%)略小于后者(76.71%);前者的相对长度系数为12L+6M2+12S,后者的相对长度系数为12L+3M1+3M2+12S;前者的最长染色体与最短染色体长度的比值(3.10)略小于后者(3.19).重瓣花型的核型公式为2n=3x=30=15st+15sm(3SAT),单瓣花型的核型公式为2n=3x=30=15st(3SAT)+15sm,崇明水仙根尖体细胞染色体的平均核型公式为2n=3x=30=15st(3SAT)+15sm.根据研究结果初步推测崇明水仙为节段异源三倍体.     

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.