磁化水浸种对苦瓜种子萌发及对其幼苗生理指标的影响

目的 :研究磁化水对苦瓜种子萌发的影响。方法 :用不同强度的磁化水浸种处理苦瓜种子 ,测定其以下几个生理指标 :种子的发芽率、发芽指数、活力指数和幼苗中的酯酶以及抗坏血酸的含量。实验结果显示 :磁化水能够提高苦瓜种子的发芽率、发芽指数、活力指数 ,同时也能提高苦瓜幼苗的酯酶活性 ,但对抗坏血酸含量影响不大。结论 :一定强度的磁化水能提高苦瓜种子的萌发能力 ,并使幼苗生长整齐一致。     

磁化水浸种对苦瓜种子萌发及对其幼苗生理指标的影响

目的：研究磁化水对苦瓜种子萌发的影响。方法：用不同强度的磁化水浸种处理苦瓜种子,测定其以下几个生理指标：种子的发芽率、发芽指数、活力指数和幼苗中的酯酶以及抗坏血酸的含量。实验结果显示：磁化水能够提高苦瓜种子的发芽率、发芽指数、活力指数,同时也能提高苦瓜幼苗的酯酶活性,但对抗坏血酸含量影响不大。结论：一定强度的磁化水能提高苦瓜种子的萌发能力,并使幼苗生长整齐一致。     

青霉素对几种作物种子发芽率和幼苗生长的影响（简报）

青霉素可提高玉米、水稻、黄瓜的种子发芽率、发芽指数、活力指数、幼苗长度及干重,可溶性糖含量、淀粉酶和抗坏血酸氧化酶活性。     

盐胁迫下黄芩种子萌发及幼苗对外源抗坏血酸的生理响应

以黄芩(Scutellaria baicalensis)种子为材料,用氯化钠(Na Cl)模拟盐胁迫条件,采用纸上发芽,研究外源抗坏血酸(As A)对盐胁迫下黄芩种子萌发及幼苗的影响。结果表明,在80 mmol·L-1 Na Cl胁迫下,黄芩种子萌发及幼苗生理指标受到显著抑制;0.50 mmol·L-1 As A处理可显著提高盐胁迫下黄芩种子的发芽势(GE)、发芽率(GR)、发芽指数(GI)、简化活力指数(SVI)以及根系总黄酮、可溶性糖和脯氨酸(Pro)含量,同时也可显著提高幼苗根系活力和超氧化物歧化酶(SOD)活性,显著降低丙二醛(MDA)含量。这说明适宜浓度的抗坏血酸能提高黄芩种子的萌发能力和幼苗对盐胁迫的适应能力,从而起到缓解盐胁迫对种子萌发及幼苗生长的抑制作用。     

KNO3引发对Ca(NO3)2单盐胁迫下茄子种子萌发和幼苗抗氧化特性的影响

通过3%KNO3溶液浸泡和室内光照培养对美引茄冠(Solanum melongena L.)在Ca(NO3)2胁迫下的种子萌发特性和幼苗耐盐性的影响进行研究.结果表明,在Ca(NO3)2胁迫下,经过KNO3引发处理的种子发芽率、发芽势、发芽指数、活力指数和幼苗干鲜重均显著高于对照;与对照相比,引发处理显著提高了幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)的活性,而丙二醛(MDA)含量则显著降低,膜脂过氧化程度较轻;引发处理植株叶片游离脯氨酸和可溶性蛋白质含量均显著高于对照.结果表明,经KNO3引发处理显著提高了茄子种子的活力并增强了其幼苗的耐盐性.     

磁化水浸种对西瓜种子萌发及幼苗生理的影响

用不同强度的磁化水(0．05T、0．08T、0．10T、0．15T)浸种西瓜种子研究磁化水对西瓜种子萌发及幼苗生理的影响,结果表明：与对照相比,各种强度磁化水浸种都能提高种子的发芽率、发芽势、发芽指数和幼苗的抗坏血酸含量,其中0．10T磁化水处理后西瓜种子发芽率、发芽势提高幅度最大;对抗坏血酸含量的影响以0．08T处理最明显;经过不同强度磁化水处理后幼苗中的过氧化物酶同工酶酶、酯酶同工酶活性得到不同强度的增强,不同品种表现不同。实验结果说明磁化水处理后能明显提高西瓜种子的萌发能力,并能提高幼苗的各种生理活性。     

甲基磺酸乙酯及~(60)Co对海甘蓝萌发种子的生理效应(简报)

海甘蓝种子经低浓度（0.1％）的甲基磺酸乙酯（EMS）或低剂量的（60kR）60Co处理后,呼吸速率增加,抗坏血酸氧化酶和过氧化物酶活性提高,种子萌发和幼苗生长也受到促进。较高浓度（＞0.1％）的EMS或高剂量（＞60kR）60Co则抑制呼吸,抗坏血酸氧化酶和过氧化物酶活性、种子发芽势和发芽率、幼苗生长高度和根系活力等也随之下降。     

水引发对油松种子和幼苗的生理效应及其作用机理

为了解决油松种子在直播造林中发芽率低、幼苗抗旱性差的问题,研究了油松种子水引发的方法及引发对其种子和幼苗的生理效应,并对水引发后幼苗的抗旱机理进行了探索。结果表明:油松种子水引发的最佳条件为10℃,闭光条件下分批给种子加水,加水总量为种子初始质量的30%,引发10 d。水引发可显著(P0.05)降低种子的半数发芽天数和硬实率,显著提高种子的发芽指数、最终发芽率和活力指数;水引发种子的可溶性糖及可溶性蛋白含量相比对照也得到提高。水引发可增加油松幼苗的茎粗、鲜重及根长,降低其相对苗高;并极显著(P0.01)提高了幼苗过氧化氢酶、过氧化物酶和根内脱氢酶活性,降低了游离氨基酸含量。干旱胁迫下,引发种子的幼苗脯氨酸和可溶性糖含量分别高于对照39.6%、118.9%,丙二醛含量低于对照93.4%,均达极显著水平。综合分析认为,水引发提高了种子可溶性糖及可溶性蛋白含量为种子萌发提供了保障,从而提高了种子发芽率,并通过增强幼苗抗氧化酶活性、降低丙二醛含量,进而增强幼苗抗氧化系统的功能,最终明显提高其抗旱性。     

He-Ne激光对水分胁迫下小麦幼苗生理特性的影响

用He-Ne激光(5.23×10-3W.mm-2)处理经不同浓度PEG6000胁迫的小麦幼苗,研究水分胁迫条件下激光辐照对小麦幼苗生理特性的影响。结果表明,He-Ne激光辐照可显著提高水分胁迫下小麦幼苗的根系活力以及抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)活性(P<0.05),并使其脯氨酸含量显著增加(P<0.05),而对其超氧化物歧化酶(SOD)的活性没有显著影响。可见,He-Ne激光可通过提高根系活力、抗氧化酶活性和脯氨酸含量来显著增强小麦幼苗的抗旱性。     

内源抗坏血酸对水稻种子萌发及幼苗生长的影响

为了解内源抗环血酸在水稻(Oryza sativa)种子中的作用,以野生型品种‘中花11’(ZH-11)、抗坏血酸合成关键酶GLDH基因的上调(超表达)株系GO-2及下调(干涉)株系GI-2为材料,研究了抗环血酸含量对其种子萌发和幼苗生长的影响。结果表明,GO-2株系的种子萌发率比野生型ZH-11高6%,比干涉型GI-2高60%。外源添加1 mmol L–1抗坏血酸后,干涉型GI-2萌发率提高了22%,GO-2及ZH-11则没有明显增加。GO-2株系在幼苗的根长、株高、分蘖数和鲜重等指标上均高于ZH-11和GI-2。实时荧光定量测定结果表明,GO-2株系叶片的GLDH基因表达量显著上调,而GI-2株系则显著下调。这说明抗坏血酸有助于维持水稻种子活力和促进水稻种子发芽和幼苗生长。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

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     

Selection with two alleles and complete dominance

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.