西蒙得木扦插繁殖技术初探

西蒙得木以雨季扦插为最佳时间 ,其半木质化嫩枝扦插成活率为 6 4 .0 % ,而木质化老枝生根率仅 3.0 %。扦插基质对插条的生根率也有直接影响 ,用沙为基质的较好。平切法插条 ,以生长调节物质吲哚丁酸、吲哚乙酸、萘乙酸和生根粉处理 ,可有效提高插条生根成活率     

IBA浓度、扦插时间对江西杜鹃和百合花杜鹃扦插生根的影响

为探明有鳞大花亚组杜鹃扦插生根的最佳IBA浓度和扦插时间,该研究以江西杜鹃、百合花杜鹃为材料,分别采用腐叶土+河沙(1:1)、泥炭+珍珠岩+蛭石(3:1:1)基质,开展了4个IBA浓度和4个扦插时间的生根试验.结果表明:IBA浓度对除老叶留存数外的所有指标有显著影响,其中100 mg·L-1 IBA处理生根率、新梢长最大,腐烂率最低,其它指标也表现良好,为最佳生根浓度;50 mg·L-1 IBA处理根幅、新梢率最大,但不定根数最少,效果其次;200 mg·L-1 IBA处理促进根系生长,但生根率较低、特别是显著抑制新梢发育;对照处理生根效果最差.扦插时间对所有生根指标均有显著影响,早春(04-18)木质化硬枝扦插除老叶留存数较差外,其它指标均表现极佳,为最适扦插时间;秋季(10-19)半木质-木质化过渡枝扦插效果其次;夏季(06-21)嫩枝及(08-16)半木质化枝生根效果极差,不宜进行扦插育苗.物种、基质对生根指标也有显著影响,百合花杜鹃扦插生根能力强于江西杜鹃,泥炭+珍珠岩+蛭石(3:1:1)基质生根效果优于腐叶土+河沙(1:1).该研究结果首次发现早春新梢萌发前采用木质化硬枝扦插可以显著提高两种杜鹃的生根效果,为该亚组杜鹃的扦插育苗提供了科学依据.     

连翘全光喷雾扦插育苗试验

以连翘半木质化嫩枝作插条,进行了不同扦插时间、不同枝条扦插部位、不同浓度生根激素处理、不同扦插基质和不同喷雾次数等全光喷雾扦插育苗试验。结果表明:在7月中旬进行扦插,截取当年生半木质化枝条的中部或梢部作插条,扦插前用浓度300～500 mg/kg的ABT-6号生根粉浸泡枝条基部0.5 h,以沙壤土作扦插基质,保持每天7～9次喷雾次数,能缩短连翘愈伤组织形成时间,显著提高生根数和生根率。     

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.     

不同季节和基质对紫蝉扦插的影响

以紫蝉Allamanda violacea不同茎段作插条,在不同季节和基质中进行扦插试验。结果表明,插条为未木质化幼茎的成活率为0,不宜作扦插繁殖材料;插条为一年生木质化茎段的在春季扦插效果最好,在沙基质中扦插成活率为50%,平均生根32条,平均根长15 cm。扦插基质以红土为最好,扦插成活率为71%,平均生根43条,平均根长21 cm。综合试验,紫蝉扦插以一年生木质化茎段为插条在红土基质中春季扦插效果最优。     

不同季节和基质对紫蝉扦插的影响(简报)

以紫蝉Allamanda violacea不同茎段作插条,在不同季节和基质中进行扦插试验。结果表明,插条为未木质化幼茎的成活率为0,不宜作扦插繁殖材料;插条为一年生木质化茎段的在春季扦插效果最好,在沙基质中扦插成活率为50%,平均生根32条,平均根长15 cm。扦插基质以红土为最好,扦插成活率为71%,平均生根43条,平均根长21 cm。综合试验,紫蝉扦插以一年生木质化茎段为插条在红土基质中春季扦插效果最优。     

不同基质和扦插时间对‘中山杉118’插条生根的影响

选择抗逆性强、性状优良的‘中山杉118’当年生枝条为插穗,开展中山杉扦插繁殖育苗试验。以重庆万州区就地取材的1/2腐土、2/3腐土、全腐土、全沙土为扦插基质,6月和9月分别进行扦插,测量插条生根率、最长根、根粗、根木质化程度等指标。结果表明,1/2腐土的‘中山杉118’插条生根率最高,适合作为‘中山杉118’扦插基质;在扦插时间上,6月扦插比9月生根率高,木质化程度大,说明6月更适合‘中山杉118’扦插繁殖。     

植物生长调节剂对鹿角杜鹃扦插繁殖的影响

以腐殖土为基质,研究了5种植物生长调节剂的4个浓度处理、以及萘乙酸(NAA)不同浓度与浸泡时间处理对鹿角杜鹃(Rhododendron latoucheae)当年生枝条扦插繁殖12个育苗指标的影响及各指标间的相关性,并运用隶属函数法对各处理组合的育苗效果进行了综合评价。结果表明:5种生长调节剂中,赤霉素(GA3)、吲哚丁酸(IBA)处理在大部分育苗指标上表现良好,为鹿角杜鹃扦插育苗的理想调节剂,吲哚乙酸(IAA)效果次之,6-苄氨基嘌呤(6-BA)、NAA处理的育苗指标表现较差;4个浓度水平上,愈伤率、腐烂率及老叶留存率总体以低浓度处理最佳,随着浓度升高效果下降;其它9个指标对浓度的响应因生长调节剂种类而异。各指标相关性分析发现,4个根系生长指标,即不定根数、最长不定根长、总根数及根系直径之间呈极显著正相关,但它们与愈伤率、腐烂率、生根率及老叶留存率、新梢率间的相关性较弱。隶属函数综合评价表明,50 mg/L GA3处理为鹿角杜鹃扦插育苗的最佳组合,其次为100 mg/L GA3和400 mg/L IBA处理。本研究为杜鹃花产业化育苗提供了科学依据。     

高质量浓度IBA和插条木质化程度对兔眼蓝浆果扦插生根的影响

采用速蘸法研究了高质量浓度(3 000、5 000、7 000和9 000 mg.L-1)IBA对兔眼蓝浆果(Vaccinium asheiReade)品种‘粉蓝’(‘Powderblue’)、‘梯芙蓝’(‘Tifblue’)和‘芭尔德温’(‘Baldwin’)插条生根率和开始生根时间的影响,并对木质化程度不同的‘顶峰’(‘Climax’)和‘雾达德’(‘Woodard’)插条的生根率和开始生根时间进行了比较。结果表明:经3 000~9 000 mg.L-1IBA溶液速蘸3 s,3个品种插条的生根率均高于或显著高于对照(P<0.05),开始生根时间则较对照明显提前,但不同品种有明显差异;随IBA质量浓度的提高,‘粉蓝’和‘芭尔德温’的生根率逐渐增加,开始生根时间逐渐提早,以9 000 mg.L-1IBA处理组的生根率最高(分别为93.98%和86.46%),开始生根时间最早(分别为15和21 d);品种‘梯芙蓝’插条的生根率则以5 000 mg.L-1IBA处理组最高(88.02%),开始生根时间最早(18 d)。木质化程度不同的插条生根率有显著差异(P<0.05),木质化程度越低,插条的生根率越高且开始生根时间越早;采用木质化程度低的插条,品种‘顶峰’和‘雾达德’插条的生根率分别达到88.54%和77.60%,开始生根时间分别为25和29 d。研究结果显示:高浓度IBA速蘸法是兔眼蓝浆果扦插生根的有效方法,在实际生产中应根据不同品种的特性选择适宜的IBA浓度;从木质化程度及插条可取数量两方面考虑宜选用半木质化枝条作为插条。     

三角梅扦插育苗技术研究

以三角梅越冬枝条及当年嫩枝作试材,分别对不同植物生长调节剂种类、不同浓度处理、不同直径插条及不同扦插时期的生根效应进行研究。结果表明,NAA、IAA和ABT(生根粉)对插条具有良好的促根作用,其中以NAA 100mg/L浸泡插条基部3h效果最佳,生根率达91.7%。健壮之越冬枝条是三角梅理想的扦插材料,初夏扦插育苗效果较好。     

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.