河水漫溢对塔里木河下游荒漠河岸林地表植被与土壤种子库的影响

采用种子萌发法,研究了河水漫溢对塔里木河下游荒漠河岸林地表植被与土壤种子库的影响.结果表明：塔里木河下游漫溢区地表植被分属8科13属14种,非漫溢区为10科21属26种植物;与非漫溢区相比,漫溢区地表植被中出现了一些浅根系和喜湿的草本植物;漫溢区单位面积物种数、植被盖度、植株密度、物种多样性指数和丰富度指数均比非漫溢区有明显增加.漫溢区土壤种子库中有物种19种,比非漫溢区增加了5种;漫溢区土壤种子库总密度比非漫溢区增加了3.94倍;与非漫溢区相比,漫溢区1年生草本植物种子的比例增加了23.07%,而灌木植物种子比例减少了20.99%;多年生草本的变化则不明显;河水漫溢提高了土壤种子库的生物多样性.漫溢区和非漫溢区土壤种子库与地表植被的共有物种分别为18和9种,土壤种子库与地表植被的相似性系数分别为0.842和 0.667.     

关于中国淡水生态系统生物多样性监测与管理的探讨

China is one of the countries in the world with therichest species biodiversityinfreshwater ecosystem.How-ever,duetothe rapid economic growthandthe continuingincrease of human disturbances and destructions of aquatichabitats,the biodiversity of freshwater ecosystemsis dras-tically declining.Waterbodies become more and more“deserted”of sensitive species.Water areas are reduced,fragmentized,and changed in their hydrodynamics(i.e.damming),causing changes in sedimentation and otherchanges.Forinstance,the area o...     

天花粉蛋白Glu189在N-糖苷酶活性中的作用

培养了(E160A,E189A)TCS(天花粉蛋白)的单晶。用浸泡法得到了(E160A,E189A)TCS与Ade复合物的晶体。在MarResearch面探测器系统上分别收集了均为0.20nm分辨率的X射线衍射数据,数据处理用MarScale程序系统完成。用同晶差值Fourier法解析了(E160A,E189A)TCS和(E160A,E189A)TCS-Ade的晶体结构,结构修正利用X-PLOR程序.修正结果,晶体学R因子分别为0.180、0.184,键长和键角的RMS偏差分别为0.0012nm和2.566°、0.0012nm和2.622°。在(E160A,E189A)TCS-Ade中,Ade仍结合在N-糖苷酶活性口袋之中,它夹在Tyr70和Tyr111两个侧链环之间,与Tyr70环近乎平行。这一结果表明:TCS中的Glu160和Glu189同时突变成Ala,仍能与AMP发生N-糖苷酶反应.前文已经证明在(E160A)TCS中Glu189没有援救作用。目前,没有发现Glu189对TCS与AMP的直接作用,但Glu189与其它残基的协同作用及其在TCS与rRNA作用中扮演什么角色,尚待进一步研究。     

DNA分子标记技术及其在药用植物研究上的应用前景

ＤＮＡ分子标记技术及其在药用植物研究上的应用前景傅荣昭１邵鹏柱２高文远３孙勇如１１．中国科学院遗传研究所,北京１００１０１２．香港中文大学生化系香港·新界·沙田３．中国医学科学院、中国协和医科大学药用植物研究所北京１０００９４ＤＮＡ分子标记（ＤＮＡｍｏｌｅｃｕｌａｒｍａｒｋｅｒｓ）或称遗传标记（ｇｅｎｅｔｉｃｍａｒｋｅｒｓ）本质上是指能反映生物个体或种群间基因组中某种差异特征的ＤＮＡ片段。这...     

激光诱发家蚕孤雌生殖的研究

采用 CO2激光扩束辐照诱发家蚕孤雌生殖,获得着色卵率约60%,转青卵率约31%,孵化率只占转青率的1.85%,全是雌蚕,其发育机制属非减数分裂型,没有出现畸形蚕,茧质未下降。从激光诱发的孤雌生殖的后代中,初步选出两个新类型的可作育种材料。 Abstrect:In order to induce silkworm(Bombyx mori)parthenogenesis,we irradiated eggs by Co2 laser.The results showed,60% colored eggs,31% average bluish eggs,only 1.85% hatchavility among the bluish eggs,all female from those eggs and so an ameiosis parthenogenesis;no malformed worm,thus similar constitution and quality to their parents;and finally two new strains which can be used to breed new strains and furhther studies.     

陆地棉产量性状的遗传效应及其与环境互作的分析

本研究根据加性-显性与环境互作的遗传模型, 分析了陆地棉10个杂交亲本和20个F1皮棉产量、单株铃数、单铃重、衣分和前期收花率的两年资料,估算了各项遗传方差分量和成对性状间各项遗传效应的相关。方差分析结果表明,衣分受基因型×环境互作效应影响较小,其它4个性状受基因型×环境互作影响较大,其中皮棉产量、单株铃数和前期收花率受显性×环境互作效应影响较大。遗传相关分析表明,皮棉产量与单株铃数、衣分和前期收花率加性相关系数值较大,皮棉产量与单株铃数、单铃重和前期收花率间存在较强的加性与环境互作负相关。皮棉产量与单株铃数、单铃重和前期收花率间存在显著的显性正相关,但与单株铃数、单铃重间存在显性与环境互作相关。 Abstract:Ten parents and their 20 F1s of upland cotton were analyzed for five yield traits in two years by a genetic model of additive-dominance with interaction effects.Genetic variance components and correlations were estimated.It was indicated that the gene by year effects interaction were small for lint percentage,but large for the other four traits,the dominance by year effects interaction were very large for lintvield,boll number and first picking percentage,especially.The additive correlation between lint yield with boll number,lint percentage and first picking percentage were significantly and high.The dominance correlations between lint yield and boll number,and between boll weight and first picking percentage were significantly too.The correlation of additive by year interaction between lint yield and boll number,boll weight and first picking percentage and those of dominance interaction by year between lint yield and boll number,boll weight were significant and large.The dominance correlation between boll number and boll weight were large too.     

糖尿病患者指纹白线的分析

作者对298例糖尿病患者的指纹白线的出现率进行了调查,结果表明,糖尿病患者的指纹白线出现率明显高于同一地区正常人群,差异高度显著(P<0 .01)。其中女性指纹白线的出现率明显高于男性,差异显著(P<0.05),较某些遗传病指纹白线的出现率低。     

云南小麦、西藏半野生小麦和普通小麦叶绿体DNA限制性内切酶图谱的研究

云南小麦(Triticum aestivum ssp.yunnanense King)和西藏半野生小麦(Triticum aestivum ssp.tibetanum Shao) 是我国西部地区特有的两个普通小麦(T.aestivum L.)亚种。我们采用改进的高离子强度法,提取云南小麦、西藏半野生小麦、普通小麦的两个品种(中国春和鄂恩1号)的叶绿体DNA, 并用7种限制性内切酶对它们的叶绿体DNA进行了酶切图谱分析。结果表明:在普通小麦及其两个亚种中没有叶绿体DNA的限制性片段长度差异,反映了叶绿体基因组在进化过程中相对的稳定性。 Abstract:Yunnan wheat(Triticum aestivum ssp. Yunnanense King) and Tibet semiwild wheat (Triticum aestivum ssp. Tibetanum Shao) are two endemic subspecies of common wheat (T. eastivum L.) in the west of China.Improved high ionic strength medium was adopted to extract the cpDNAs of Yunnan wheat,Tibet semiwild wheat and two cultivars of common wheat (Chinese Spring and Een 1).Restriction fragment analysis of cpDNAs was carried out with the use of 7 restriction enzymes.The results showed that there was no diversity of cpDNAs from common wheat and the two subspecies,indicating the conservatism of the chloroplast genome during the process of evolution.     

Human chromosome pellicle antibody recognizing centromere protein-C (CENP-C), the main component of the kinetochore

INTRODUCTIONDuringnormalcelldivision,thechromosomesplitsevenly,givingthesamegeneticmaterialtoeachdaughtercell.Theaccuracyofsuchcelldivisiondependsontheinteractionbetweenthespindleapparatusandtheets--actingregionofeachchromosomeknownasthecentromere.Manyessentialmitoticfunctionsoccuratorarecontrolledbythecentromere.Capturingspindlemicrotubules,thegrowthanddisassemblyofmicrotubules,theliningupofchromosomesonthemetaphaseplate,andthesplittingoffofthesisterchromatidsduringmitosisareallsomehowre…     

动物数量性状选择的C语言程序

本文仅从实用角度出发,通过应用示例给出根据正态分布原理进行家畜数量性状选择的C语言程序,为实际选种提供方便。 Abstract:By using of instance,this paper gives C program about animal selection by the principle of normal distribution,Provides convenience for practice selection.