圆籽荷(Apterosperma oblata)扦插繁殖试验

圆籽荷(Apterosperma oblata)是我国特有单种属珍稀濒危植物, 其自然繁殖更新困难。采用全因素试验设计方法开展了圆籽荷扦插繁殖试验, 研究了插条类型、生根剂、生根剂浸泡时间等因素对其扦插生根的影响, 以筛选出较优的扦插繁殖方法。研究结果表明: (1)插条类型和生根剂对圆籽荷插条生根的影响极显著(P<0.01), 浸泡时间对圆籽荷扦插生根的影响显著(P<0.05); 生根剂与浸泡时间之间以及插条类型、生根剂、生根剂浸泡时间三者交互作用效应也达到了极显著水平(P<0.01)。(2)各因素最佳处理水平分别是: 软枝插条, 浸泡时间2h 和6h, 生根剂为120 mg·L1吲哚丁酸(IBA)和60 mg·L1 萘乙酸(NAA)。(3)圆籽荷扦插较优方案为: 软枝插条、120 mg·L1IBA、6h, 其生根率为66.67%。     

千层金嫩枝扦插繁殖技术

本研究用L_(16)(4~5)正交试验方法,研究了基质、穗条长度、植物生长调节剂及其浓度对千层金嫩枝扦插生根率的影响.结果表明,基质和生长调节物质对生根率有极显著的影响,而植物生长调节剂浓度与穗条长度对生根率有显著的影响,4个因素对干层金嫩枝大田扦插生根率影响从大到小分别是基质、生长调节物质、植物生长调节剂浓度和穗条长度.用浓度100 mg/L的NAA浸泡9 cm插穗2 h,在混和基质上扦插,平均生根率可达92%,且生根及新梢抽出时间早,侧根数量多,扦插效果最好.     

小果核果茶扦插繁殖技术研究

小果核果茶为山茶科石笔木属常绿乔木,树形美观,叶泽光亮,洁白亮丽的花朵和茂密的果实具有较高的观赏价值;而且其种子含油量高,是一种具有潜在开发价值的新型生物能源植物。该研究采用4因素3水平的正交设计,分析了激素种类、处理浓度、浸泡时间和扦插基质对小果核果茶扦插生根的影响,并以生根率、生根数和平均根长为扦插生根效果的评价指标,构建生根效果指数,总体评价小果核果茶的生根效果。结果表明:对生根效果指数影响最大的是扦插基质,激素种类次之,影响最小的是处理时间。其中,扦插基质对生根效果指数的影响达到显著水平(P0.05);当激素种类为NAA、处理浓度为500mg·L~(-1)、处理时间为12 h、扦插基质为泥炭土时,小果核果茶扦插的生根效果最好。该研究结果为小果核果茶的栽培生产、育种以及资源开发和利用提供了科学依据。     

长白落叶松插穗的内源激素水平及其与扦插生根的关系

长白落叶松 (Larixolgensis)扦插繁殖的试验结果表明 ,嫩枝扦插效果好于硬枝扦插 ,并且母树年龄是影响其扦插生根的重要因子。母树年龄为 2年生时 ,生根率达 95 %以上。本文在此试验的基础上 ,对嫩枝和硬枝插穗中内源植物激素水平进行了测定。结果发现嫩枝插穗中IAA、CTKs的含量要高于硬枝插穗中IAA、CTKs的含量 ,并且随母树年龄的增加而降低 ;相反 ,嫩枝插穗中ABA含量要低于硬枝插穗中ABA的含量 ,并且随着母树年龄的增加而增加。实验结果表明 :IAA、ABA的含量和扦插生根有密切关系。IAA促进生根 ,ABA抑制生根。IAA/ABA比值可以用来衡量长白落叶松的生根能力     

日本落叶松扦插生根期内源激素和营养物质及酚酸含量变化特征

以生根能力差异较大的4个日本落叶松无性系为材料,对插穗生根过程中插穗内源激素含量和比值,以及总酚酸和营养物质含量的变化进行分析,以明确插穗不定根形成的主要内源性影响因素,为日本落叶松扦插繁殖技术提供理论依据.结果表明:(1)4个日本落叶松无性系扦插生根能力存在显著差异,‘日宽17-3-1'和‘日抚273 1,较易生根,其生根率达90％,而‘日草103-3-1’和‘日草82 4-3’难生根,其生根率低于20％.(2)在扦插生根过程中,插穗内源脱落酸(ABA)含量随扦插时间的延长而不断升高,并且较易生根和难生根无性系差异明显,与插穗的生根能力有较强的相关性;玉米素(Z)和总酚酸含量随扦插时间的延长而不断降低,并且对插穗生根具有明显的抑制作用;总氮含量表现出不断降低至逐渐稳定的趋势,但与插穗生根能力大小并无较强的相关性.(3)(IAA+Z)/ABA随扦插时间的延长而不断降低,且较易生根型小于难生根型.因此,在生产中以(IAA+ Z)/ABA的比值和总酚酸含量大小可判断日本落叶松插穗的生根能力.     

沙生柽柳扦插生根过程插穗相关理化特征分析

选取沙生柽柳半木质化枝条进行苗床扦插,通过实验测定插穗生根过程中内源激素(IAA、GA3、ZR、ABA)含量、可溶性营养物质(糖、蛋白质)含量及相关氧化酶(PPO、POD、SOD、IAAO)活性的动态变化特征,探讨沙生柽柳插穗扦插生根机理。结果表明:(1)沙生柽柳插穗内源激素含量随生根进程而发生变化,其中,IAA含量在扦插35d最大,并出现较大的波动变化;ZR含量在扦插55d前后变化明显,呈现低水平向高水平转化趋势;ABA、GA3含量依次呈先升高后降低再升高的变化过程,并在扦插15d和55d(80d)呈现变化的峰值和谷值。(2)沙生柽柳扦插生根与相关氧化酶活性密切相关,其中,POD、IAAO活性在插穗扦插35d后长时间保持较高水平,直至插穗生根后POD活性明显降低,IAAO活性有所增加;PPO、SOD活性则在插穗扦插15d保持较高活性,且PPO活性的变化均匀,SOD活性的高低交替变化明显。(3)在沙生柽柳扦插生根期间,插穗可溶性糖含量呈现生根前消耗减少与生根后积累增加两大变化过程,可溶性蛋白质含量表现为扦插后逐步积累增加的变化趋势。研究表明,高水平的IAA、ZR和低水平的GA3、ABA共同调控着沙生柽柳插穗生根;IAA能够通过促进插穗POD、PPO、IAAO活性变化来影响生根,较高的POD、IAAO活性可调节插穗IAA水平,高水平的PPO活性则催化插穗IAA-酚酸复合物的形成,进而诱导插穗生根。     

南板蓝扦插繁殖技术研究

研究了不同基质、插穗不同部位、不同节数和不同植物生长调节剂对南板蓝扦插繁殖的影响。结果表明, 不同基质、插穗不同部位、不同节数和不同植物生长调节剂对插穗生根的影响均有显著差异。其中以河沙∶珍珠岩=2∶1混合基质的扦插效果最好、生根率达93.3%;顶部插穗的生根率达94.2%;2节插穗的生根率为90.7%;100mg/LIBA扦插生根率最高,达94.5%。采用适当的方法有利于提高南板蓝扦插的繁殖系数。     

草珊瑚扦插技术研究

采用4因素3水平L_9(3~4)正交试验法,以生根率、生根数和平均根长为生根效果的评价指标,研究扦插基质、萘乙酸、吲哚丁酸、插穗部位对草珊瑚Sarcandra glabra扦插生根效果的影响。结果表明,插穗部位对草珊瑚扦插生根效果影响最大,其次是扦插基质,吲哚丁酸对扦插生根有抑制作用,萘乙酸则没有显著影响。草珊瑚扦插繁殖时用顶部插穗,扦插基质采用含沙黄土生根效果最好,生根率达98.12%,生根数每棵12.11条,平均根长8.31 cm。     

IBA与NAA对桃金娘扦插繁殖的影响

采用二元二次回归通用旋转组合设计,探讨植物生长调节剂IBA、NAA对桃金娘Rhodomyrtus tomentosa扦插生根的影响。结果显示,适宜浓度的IBA和NAA有利于桃金娘的扦插生根,IBA对生根率、根长和根重的影响更为明显。最佳浓度组合为IBA、NAA各100 mg·L~(-1),用该组合处理插条,可有效地提高扦插繁殖的成活率及幼苗质量。     

NAA处理对艾纳香扦插生根生理生化特性的影响

为探讨NAA对艾纳香(Blumea balsamifera)扦插生根的影响,4 a生艾纳香健康枝条用500 mg/L NAA处理,对生根过程中的生理生化特征进行了研究.结果表明,艾纳香扦插生根率与内源IAA、GA含量和IAA/ABA呈正相关,而与ABA含量呈负相关.NAA处理能提高插穗的IAA含量,降低ABA含量,有助...     

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.