首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
本文首次报道了我国的一个待识别民族-芒人的13项肤纹参数, 并将13项参数与汉族比较,大多有显著或高度显著性差异。同时,本文还报告了对芒人PTC味盲频率的调查分析结果。  相似文献   

2.
费炎灵  童一中 《遗传》1990,12(3):13-16
“蟹脚芒”小麦是从八倍体小偃麦中-5,与普通小麦晋革早杂交后代中选育出来的新品种。“蟹脚芒”小麦的芒性“蟹脚芒”是一种新发现的芒性性状。本文对“蟹脚芒”小麦的芒性性状作了详细记载,并运用中国春单体系统[10]对“蟹脚芒”性状进行染色体定位研究。  相似文献   

3.
对Hystrixduthiei、H.longearistata和它们的人工种间杂种花粉母细胞减数分裂染色体配对行为、繁育特征和形态特征进行了比较分析,结果表明:91)这两个分类单位形态差异较小,H.longearistata的外稃芒较长,叶片较宽,每小穗具2-3个小花;H.duthiei的外稃荒较短,叶片较窄,每小穗具1-2个小花。(2)它们很容易杂交,杂种F1染色体配对频率很高,为13-14个二  相似文献   

4.
目前芒属植物被视为最有前景的木质纤维素能源作物,在中国、美国、日本和欧洲国家得到了广泛研究和利用。但截至目前依然没有统一的芒属植物种质资源描述规范,一定程度上阻碍了其信息的共享与交流。鉴于此,本研究通过开展芒属植物种质资源描述和数据制定技术标准研究,旨在为芒属能源作物品种的选育、审定与推广提供科学规范的依据。本文论述了芒属种质资源描述规范、数据标准与数据质量控制规范的制定原则、方法与内容,对于促进整合全国芒属种质资源,规范芒属种质资源的收集、保存、评价具有指导作用。  相似文献   

5.
叶雨  王柏磊 《蛇志》2012,24(2):99-101
目的观察芒柄花黄素在体外对人脐静脉内皮细胞(HUVEC)增殖及周期的影响。方法采用四甲基偶氮唑蓝(MTT)法检测不同芒柄花黄素对HUVEC增殖的影响,流式细胞术检测细胞周期,Western blot检测cyclin D1蛋白表达水平。结果芒柄花黄素呈剂量依赖性促进HUVEC增殖。且药物作用后,S期细胞比例增加,cyclin D1蛋白表达升高。结论芒柄花黄素对人脐静脉内皮细胞有明显的促进增殖作用,可通过上调cyclin D1蛋白表达增加S期细胞比率。  相似文献   

6.
达斡尔族人肤纹学研究   总被引:4,自引:2,他引:2  
赵荣枝  孙慧 《人类学学报》1990,9(3):223-230
本文报告1000名新疆塔城地区达斡尔族人12项手纹参数正常值,对达斡尔人男、女性及左右手的肤纹学差异进行了分析并比较了达族与汉族及新疆其他民族的肤纹差异。  相似文献   

7.
芒属植物重金属耐性强,并且是重要的能源植物,其在矿山废弃地植被恢复中的应用备受关注.芒属植物对多种重金属耐性强,但不属于重金属超累积植物.目前的研究认为,根系代谢能力强、根际存在多种共生微生物及抗氧化和光合作用能力强是芒属植物重金属耐性强的重要原因,但更为全面的耐性机理需要深入研究.芒属植物在矿山废弃地植被恢复的应用潜力大,可以清除土壤重金属、改善土壤性质和促进生物多样性发展.本文总结分析了芒属植物生物学特性、重金属耐性特点、机理及其在矿山废弃地植被恢复中的应用潜力,提出了应用芒属植物进行矿山废弃地植被恢复的基本思路,并对芒属植物的重金属耐性机理及应用的未来研究方向进行展望,以期为利用芒属植物开展矿山废弃地植被恢复提供借鉴.  相似文献   

8.
芒柄花素的放射免疫测定法   总被引:6,自引:0,他引:6  
本文建立了芒柄花素(formononetin)的放射免疫测定法(RIA)。该方法利用芒柄花素的衍生物作为同位素示踪物,获得的针对芒柄花素—7-O—羧甲基—牛血清白蛋白(BSA—F)的抗血清对芒柄花素具有高的亲和性(Ka=6.8×10~9 L/M)。方法的检出限量为3.5±1.24 ng(n=13),检出范围为3.5—100 ng。用此方法测定红三叶草(Trifolium pratense L.)中的芒柄花素含量,批内、批间的平均误差分别为6.5%和11.9%,加样回收率平均为98.5%。红三叶草中芒柄花素含量为0.1305±0.495%(n=12)。南京地区夏季杂牧草饲料中芒柄花素含量为0.0062±0.030%(n=6)。并用此方法测定了饲喂红三叶草的湖羊血清中芒柄花素的血浓-时间曲线图。  相似文献   

9.
 本文用离体快速称重法对宁夏盐池长芒草天然草地和苜蓿人工草地的水分利用状况进行了比较研究。研究发现:很干旱的苜蓿草地具有较高的生物量,而在水分条件相对较好的长芒草草地中生产力却很低。苜蓿草地的蒸腾耗水量占蒸散量的86.9%,而长芒草草地中只占40.7%。水分利用强度苜蓿草地为137.32%,而长芒草草地为88.72%,而且有迹象表明,苜蓿草地的水分利用深度超过了180cm,而长芒草草地则保持在180cm范围之内。两草地的蒸腾效率在整个生长季中基本一致,而蒸散效率苜蓿草地为0.82‰,长芒草草地为0.54‰。经过一个生长季,苜蓿草地水分亏缺达-101.8mm,而长芒草草地为-17.6mm。  相似文献   

10.
对芒属17种植物的自然资源状况,从分类学、遗传育种学和生理学等方面研究的进行了综述,梳理了芒属植物资源利用现状,并展望了芒属植物的应用前景和产业价值。同时指出,对芒属类群的研究深度和应用程度极不均衡,对适应于极端环境的地区特有类群开发利用不够。为全面促进芒属植物资源开发利用,助力芒属新品种的研发和推广,倡议加强极端环境下芒属种质资源研发,实现更广阔的应用前景。  相似文献   

11.
12.
13.
14.
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

15.
16.
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

19.
20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号