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 62 毫秒
1.
玉米果穗超弱发光特性的研究   总被引:3,自引:0,他引:3  
玉米果穗的超弱发光特性与籽粒成熟度及籽粒着生部位有关。随着成熟时水分的散失和干物质的积累,发光由强到弱,成熟期为发光最低值。超弱发光可反映出玉米籽粒营养物质的转化动态。试验证明玉米果穗不同发育阶段的生理代谢与超弱发光密切相关。  相似文献   

2.
绿豆和花生的超弱发光   总被引:1,自引:0,他引:1  
对黄化绿豆幼苗先形态建成过程的超弱发光图象(延迟发光)的初步观察发现:见光培养40min后的绿豆幼苗即可探测到明显的延迟发光;见光时间越长,光诱导的延迟发光强度也越强。从绿豆和花生幼苗的趋弱发光图象来看,生长健壮的幼苗发光较强。其中茎尖和新生幼叶的延迟发光最强,上胚轴、子叶和下胚轴弯钩较强,下胚轴伸长部分次之,根部发光最弱。从不同发育阶段叶片的超弱发光图象来看,光合作用较强、新陈代谢旺盛的成熟叶片的超弱发光较强;光合作用和其它代谢过程相对较弱的叶片(伸展叶、老叶和幼叶),其超弱发光强度相应较弱。而叶绿素提取液和失活绿叶观测不到超弱发光。此外,对超弱发光光谱的初步研究表明它很可能来自光合作用中叶绿素的发光。这些都暗示,植物的(诱导)超弱发光与光形态建成和光合作用等生长代谢过程密切相关。  相似文献   

3.
生物超弱发光及其应用研究概述   总被引:13,自引:2,他引:11  
生物超弱发光是生物物理中光生物学的重要内容之一,自1923年以来,人们已进行了大量研究。本文评述了生物超弱发光的机理、测量和理化影响因素,总结了生物超弱发光在我国农业和医学中的应用研究,并对初步展望了生物超弱发光的未来研究方向。  相似文献   

4.
本文利用CO2激光照射青椒、茄子干种子后,观察刺激剂量、半致死剂量对种子及幼苗生长点超弱发光的影响,从而探索超弱发光是否可作为激光照射后衡量种子活力综合反应的一项指标。其结果表明:1.青椒、茄子干种子超弱发光的动态变化随着照射间隔期的延长,其不同剂量之间超弱发光强度的差异也相应变小,照射时间最长的半致死剂量组25″、35″,其超弱发光由最高降为最低;激光刺激剂量组3″、13″的超弱发光强度始终高于CK。2.青椒、茄子种子发芽过程中超弱发光表现为激光刺激剂量组均极显著高于CK;半致死剂量25″、35″均极显著低于CK。3.激光组的活体生长点和提取液的超弱发光均极显著高于CK;活体生长点的超弱发光低于提取液的超弱发光。  相似文献   

5.
生物超弱发光研究   总被引:5,自引:0,他引:5  
生物超弱发光是自然界普遍在的一种生命现象。本文概述了近年来生物超弱发光研究的进展,探讨了生物超弱发光在医学和农业上应用的可能性,并提出了该领域有待深入研究的问题。  相似文献   

6.
生物样品超弱发光图象的探测与分析   总被引:13,自引:1,他引:13  
介绍了生物超弱发光图象探测系统及其原理。利用该系统对与黄化绿豆芽叶绿体形成相应的光诱导超弱发光(UWL)图象进行了实时观察。认为,叶绿体在生物超弱发光中起重要作用,但植物的超弱发光不是叶绿素本身直接受光照射后的瞬发荧光。另外,对几种不同生物样品的超弱发光图象进行了探测。实验表明,对应生物的不同生长代谢阶段及不同部位有不同的超弱发光强度。利用这种探测和分析,可以得到一种无损探测生物的生理、生化状态及变化过程的直观、灵敏的实用方法。  相似文献   

7.
白菜叶绿体的超弱发光机理初探   总被引:1,自引:0,他引:1  
从先前对黄化绿豆幼苗光形态建成过程和花生叶片不同发育阶段的超弱发光 (UBE)图象的初步观察结果来看 ,植物的 (诱导 )超弱发光与光形态建成和光合作用等生长代谢过程密切相关 (李德红等 ,1998)。我们在此工作的基础上 ,利用自行研制的超弱发光图象探测系统对叶绿体的超弱 (延迟 )发光进行了研究 ,并初步探讨了温度和某些化学试剂对叶绿体超弱发光的影响。实验材料选用白菜 (BrassicapekinensisRupr .)叶片 ,按通常的方法分离纯化叶绿体 ,经相应处理后分别装于比色皿中 ,按前文的方法观测其超弱发光。叶绿体无论…  相似文献   

8.
采用光子计数成像系统(PIAS)对植物幼苗萌发过程的超弱发光进行观察。结果表明,自发光子长时间积累可形成二维图象;光子计数和采集图象均可得到植物体的自发发光;通过实验探测到幼苗的根,叶在同一平面图象有不同的发光表现;光子成像系统可客观地比较生物自发超弱发光,为进一步研究超弱发光机理提供实验基础。  相似文献   

9.
血清的超弱发光与疾病诊断   总被引:12,自引:2,他引:10  
血清或血浆中存在着与脂质新陈代谢相关联的超弱发光的现象。机体病变时,血清的超弱发光会发生相依的变化。因此,血清趋弱发光的变化可以作为疾病的辅助诊断之用。本文简要地介绍了血清的发光机理、探测方法、影响因素及在某些疾病诊断中的应用。  相似文献   

10.
成熟小麦抗穗发芽能力与超弱发光关系的研究   总被引:10,自引:0,他引:10  
生物体的超弱发光表现与其本身的生理活动密切相关,利用超弱发光为指标,测定和比较了小麦不同品种在成熟时抗穗发芽的能力.为其进一步应用,解决农业实际问题提供方法和依据.  相似文献   

11.
12.
13.
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   

14.
15.
16.
17.
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   

18.
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   

19.
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   

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