大菊品种花期和主要观赏性状的变异及相关性分析

以菊花（Chrysanthemum×morifolium Ramat.）大菊品种自然群体及7个杂交群体为实验材料,分析比较了不同品种开花期和7个主要观赏性状的变异特点及其相关性,为筛选杂交亲本和选育早花优良品种提供依据。结果显示：大菊自然群体的8个性状中,除开花期外,其余性状变异系数均高于15%;相关性分析结果表明,开花期和封顶叶片数之间呈显著负相关;开花持续期与开花期呈极显著负相关,与舌状花轮数呈极显著正相关。杂交群体的8个性状中,除开花期外,变异系数均高于15%,但各杂交群体的开花期性状变异系数明显高于自然群体;杂交群体Ⅲ和Ⅴ的瓣型与花色更为丰富,且花期也较早。相关性分析结果表明,开花期和瓣型、舌状花轮数、封顶叶片数之间均呈极显著负相关,和花色之间呈显著负相关;开花持续期和舌状花轮数、舌状花数量之间呈极显著正相关,和瓣型之间呈极显著负相关,和花色之间呈显著负相关;开花期和开花持续期之间呈极显著正相关。研究结果表明,通过有性杂交可以获得开花期变异更广泛的子代植株,从而筛选开花期更早的大菊新品种。     

春萝卜抽薹过程中内源激素含量变化分析

采用酶联免疫吸附法(ELISA)测定了春萝卜抽薹过程中顶端生长点处嫩叶的赤霉素(GA₄)、生长素(IAA)、细胞分裂素(iPA)和脱落酸(ABA)等含量的变化情况。研究结果表明,在萝卜抽薹过程中,GA₄含量在现蕾点存在明显的峰值,表明GA₄与现蕾抽薹密切相关,起着主导作用;内源ABA含量变化与GA₄变化趋势基本一致;与GA₄和ABA含量相比,抽薹过程中叶片IAA含量相对较低;iPA含量在现蕾期逐步增加,至抽薹中后期出现一高峰值。研究发现iPA/ABA值增大,GA₄/iPA和GA₄/IAA值变小有利于花芽分化后萝卜植株抽薹开花,表明内源激素之间的平衡对萝卜抽薹开花也起着重要作用。     

基于黄花菜产量与品质特征的优异种质筛选及评价

为筛选黄花菜(Hemerocallis citrina)优异种质资源,采用相关分析、逐步回归、通径分析和基于逼近理想解排序(TOPSIS)分析等方法,对20份菜用黄花菜种质的产量形成与品质进行了综合评价。结果表明,不同黄花菜种质的农艺、产量和品质性状变异丰富,变异系数为1.9%～75.6%,其中以花蕾色度a*值的变异系数最大,总黄酮含量、花蕾质量次之,花蕾含水量最低。花蕾质量、花蕾粗和花薹数与产量均呈显著或极显著相关,相关系数分别为0.737、0.583和0.517。营养品质间的相关性较弱,而外观颜色指标间及其与部分营养品质存在极显著相关性。影响黄花菜产量的主要决定因子为花蕾质量和花薹数,其决策系数分别为0.534和0.239。营养品质和外观颜色的权重分别为0.523和0.477,结合TOPSIS法可以对不同种质的品质进行有效区分。根据综合得分与产量绘制二维散点分布图可以快速筛选到产量与品质均佳的优异资源。     

63份谷子种质的耐盐综合评价及耐盐品种筛选

谷子是我国北方重要的粮食作物,具有较强的耐盐抗旱能力。盐碱地是我国重要的后备耕地资源,加强谷子种质耐盐评价,筛选耐盐碱的谷子品种对促进盐碱地资源利用、保障国家粮食安全具有非常重要的作用。本试验以63份谷子种质资源为研究对象,以1.0%质量浓度NaCl溶液进行盐胁迫,用蒸馏水作为对照,采用全营养培养基发芽法在人工气候培养箱(昼/夜,30℃/20℃,光周期14 h/d)中进行谷子种质萌发期的耐盐性鉴定;利用相关性分析和主成分分析明确8项耐盐指标在耐盐性评价中的权重;通过模糊数学中的隶属函数法和聚类分析法对63份谷子种质的耐盐性进行综合评价和耐盐等级划分。结果表明:谷子种质资源的耐盐性存在广泛的变异;1.0%质量浓度的盐胁迫下,谷子的发芽率、发芽指数、根长、芽长、相对芽长、相对根长之间互成极显著正相关关系,而与相对盐害率呈极显著负相关;主成分分析结果表明,发芽率、发芽指数、相对芽长、相对根长可作为谷子耐盐性评价的关键指标;通过聚类分析可将63份谷子种质分为极端耐盐种质、耐盐种质、盐敏感种质和极端盐敏感种质4类;基于模糊数学中的隶属函数得分进行综合评价,筛选获得了济谷16、汾特11号、峰红谷、晋谷57、晋汾106号等5份耐盐谷子品种。     

萝卜种质资源对黑腐病的抗性鉴定与筛选

对40份初选萝卜种质分别接种Xcc8004和XccBJ两个菌株,进行黑腐病苗期抗性鉴定,对其中8份代表性萝卜种质肉质根切片接种Xcc8004进行抗性鉴定和27份萝卜种质幼苗接种8个效应物基因进行过敏反应鉴定。结果表明:不同萝卜种质苗期对黑腐病的抗性存在显著差异,筛选出高抗Xcc8004的材料3份、抗病1份、中抗4份,高抗XccBJ的材料1份、抗病2份、中抗5份。萝卜苗期对Xcc8004和XccBJ的抗病性极显著相关,幼苗和肉质根对Xcc8004的抗病性极显著相关。筛选出17份对不同效应物表现过敏反应的萝卜种质。对效应物XC₀241表现过敏反应的种质数最多,对XC₀542和XC₀541表现过敏反应的种质数次之。不同抗源对不同效应物的过敏反应程度有所不同。稳定可靠抗病资源的获得为萝卜抗病育种和抗病机理的深入研究提供了基础材料。     

甘蓝耐裂球性评价方法研究及种质鉴定筛选

裂球是甘蓝生产中存在的一个严重问题。本研究通过对7份春甘蓝和8份秋甘蓝不同耐裂性材料的田间裂球方式、裂球率、裂球程度比较,综合最大裂口层数、裂口面积,建立了甘蓝耐裂球性评价方法并制定了甘蓝个体裂球分级标准。根据春甘蓝叶球成熟后5天、秋甘蓝叶球成熟后15天的裂球指数将甘蓝种质群体的耐裂球性分为极耐裂球、耐裂球、中耐裂球、易裂球、极易裂球5级。对59份春、秋甘蓝种质进行耐裂球性鉴定筛选获得一批极耐裂甘蓝种质资源。同时,对甘蓝室内成熟叶球浸泡法评价耐裂球性进行了初探。首次提出室内浸泡能够准确的鉴定甘蓝的耐裂球性,可用于选育耐裂球品种及生产实践。通过本研究制定出一套春、秋甘蓝耐裂球性的田间及室内鉴定方法与标准,筛选获得不同甘蓝耐裂球种质,为甘蓝耐裂球性研究和育种应用提供技术支撑和优异材料。     

油菜生长发育期间内源激素含量的变化

初花期至盛花期华双3号、华杂4号、恢5900等3个品种花蕾的iPAs含量呈明显上升趋势,而秦油2号则刚好相反(表2)。对双低品种华双3号功能叶的研究表明：苗期至盛花期IAA含量始终最高,其后依次是GA1 3;、iPAs、ABA。功能叶IAA的含量在越冬期处于整个生育期的最低水平,蕾薹期达到高峰,随后下降：GA1 3和iPAs含量随生育进程逐渐升高,并在初花期达到峰值;ABA在苗期及抽薹后一直处于很低水平,但在越冬期达到最高值(图1、2)。蕾薹期IAA主要分布在幼嫩和正在生长的器官中并起重要作用,而在功能叶中相对要少;幼叶GA1 3和iPAs含量最高,功能叶其次,花蕾最低(表1)。角果皮与籽粒的内源激素含量差异极显著,在开花后第39天,籽粒中IAA、GA1 3;、iPAs的含量大大超过角果皮(表3)。结果 表明iPAs在促进籽粒的充实饱满、物质积累转化方面发挥重要作用。     

大蒜种质资源对蒜蛆的抗性评价

就大蒜种质资源对蒜蛆的抗性进行了虫圃田间鉴定,并对抗性与大蒜主要植物学性状和大蒜辣素含量的相关性进行了分析。结果表明:52份材料的感虫指数分布在7.14~90.38之间,种质资源间抗虫性差异达到了显著水平;聚类分析并结合感虫指数将52份种质资源分为高抗、抗、中抗、中感、感、高感6个类别,其中高抗和抗性材料分别为4份和8份。相关分析表明:感虫指数与植株的7个形态数量性状的相关性均未达到显著水平,而与鳞茎的鳞芽背宽、鳞茎的大蒜辣素含量均呈极显著的负相关,即抗性与二者显著正相关。表明大蒜辣素含量越高,大蒜对蒜蛆的抗性越强;从鳞芽背宽较宽和高大蒜辣素含量的大蒜资源中筛选抗蒜蛆的种质可能性更大。     

黄麻种质芽期和苗期耐盐性的鉴定与评价

本研究以12份黄麻种质为材料,芽期采用萌发实验法、苗期采用营养液栽培法,进行耐盐性鉴定与评价.结果表明:芽期耐盐性鉴定及其耐盐等级划分可以相对盐害率为指标,而苗期则以平均盐害指数为指标.黄麻芽期耐盐性与苗期耐盐性之间存在极显著相关性(r=0.8432**,n=10);经筛选获得了3份高耐盐材料:9511、中黄麻1号、93繁-13,耐盐等级均为1级;1份盐敏感性材料:孟圆,芽期耐盐等级为5级,苗期耐盐等级为4级.     

Ⅳ.罗布麻在陕西的花期及我国西部类型引种后发育上的变化

罗布麻花朵繁多、有蜜腺、花期相当长,使该植物除医药、纤维用途外,又可能作为蜜源植物。本文观察分析罗布麻地区类型引入陕西后的现蕾、开花期等发育方面的表现。１供试材料罗布麻地区类型９３份,计来源于１０个省区,其中新疆白麻３６份（包括种子１６份、原产地根茎...     

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.