传粉导致的转基因白菜与其近缘种属材料间的基因流动

从形态、染色体及分子水平上证实,转基因不结球白菜(Brassica campestris ssp．chinensis var．utilis Tsen et Lee)中编码除草剂Basta抗性的bar基因能在田间条件下,经自然传粉,以较高频率侵入芜菁(B．campestris ssp．rapifera)、结球白菜(B．campestris／sssp．pek／nens／s)和不结球白菜(B．campestrs ssp．ch／nens／s)的基因组中,也能少量侵入同属异种的甘蓝型油菜(B.napus)基因组中;在温室人工辅助授粉条件下,除在上述种中的基因漂移率提高外,bar基因尚能以一定频率侵入同属的黑芥(B．nigra)、埃塞俄比亚芥(B．car／nata)、芥菜(B．juncea)基因组中,但始终未能得到转基因白菜与结球甘蓝(B．oleracea)、萝卜(尺．sativus)的杂种。转基因白菜与十字花科的7种常见杂草经温室人工辅助授粉,也均未得到抗性杂种。     

传粉导致的转基因白菜与其近缘种属材料间的基因流动

从形态、染色体及分子水平上证实,转基因不结球白菜(Brassica campestris ssp. chinensis var. utilis Tsen et Lee)中编码除草剂Basta抗性的bar基因能在田间条件下,经自然传粉,以较高频率侵入芜菁(B. campestris ssp. rapifera)、结球白菜(B. campestris ssp. pekinensis)和不结球白菜(B. campestris ssp. chinensis)的基因组中,也能少量侵入同属异种的甘蓝型油菜(B. napus)基因组中; 在温室人工辅助授粉条件下,除在上述种中的基因漂移率提高外,bar基因尚能以一定频率侵入同属的黑芥(B. nigra)、埃塞俄比亚芥(B. carinata)、芥菜(B. juncea)基因组中,但始终未能得到转基因白菜与结球甘蓝(B. oleracea)、萝卜(R. sativus)的杂种.转基因白菜与十字花科的7种常见杂草经温室人工辅助授粉,也均未得到抗性杂种.     

西藏野生油菜性状演化与分支分类研究

以西藏野生白菜型油菜（Brassica campestris L．）和野生芥菜型油菜（B．juncea Czern．et Coss．）的39个形态学性状为依据,以醉蝶花（Cleome spinosa Jacq．）为外类群,确定了性状的祖征和衍征。应用最大同步法,对35个西藏野生油菜种源的性状演化与分支分类进行了研究。结果表明,野生白菜型油菜和野生芥菜型油菜的基生叶、薹茎叶和花器官性状既有同期演化性状也有非同期演化性状;而伸长茎叶的所有性状均为非同期演化性状,有各自独特的演化规则。西藏野生白菜型油菜分为藏东野生白菜型油菜和藏中野生白菜型油菜2个组,野生芥菜型油菜分为藏中西野生芥菜型油菜和藏南野生芥菜型油菜2个组,各自沿不同的路线演化。     

北京地区油菜软腐病病原菌的鉴定

摘要:【目的】确定引发北京地区油菜［Brassica campestris L．ssp．chinensis (L.) Makino var． communis Tsen et Lee］软腐病的病原。【方法】结合病原菌形态、BIOLOG 及生理生化、16S rＲNA 基因序列及亚种IGS区特征分析,对从北京大兴和通州区油菜软腐病样中病原菌进行生物学鉴定。【结果】分离的40 个菌株均能引发 油菜软腐病,但分别为胡萝卜果胶杆菌(Pectobacterium carotovorum) 的2个不同亚种,其中13株为P．carotovorum subsp．carotovorum(Pcc),另27株为P．arotovorum subsp． brasiliensis(Pcb)。接种白菜(Brassica campestris L．ssp．pekinensis)致病力测定分析表明,亚种内、来源相同与16S rRNA基因序列相同的菌株间均存在明显的致病力分化。【结论】Pectobacterium carotovorum subsp．carotovorum和Pectobacterium carotovorum subsp. brasiliensis是引发北京地区油菜软腐病的致病菌,后者为首次报道能引起白菜类蔬菜软腐病的常见致病菌。     

芸苔属植物油菜的新种合成及其细胞遗传学研究——Ⅳ.欧洲油菜aacc与其两个基本种a′a′和c′c′之间的染色体组替代研究

为了探索使甘蓝型欧洲油菜(Brassica napus,aacc,n=19)能否与其两个基本种甘蓝(B.oleracea,cc,n=9)和白菜型油菜(B.campestris,aa,n=10)的染色体组之间,同时进行替代更新,并且在染色体数目上能够很快地稳定下来,因而尝试利用染色体组替代的技术方法,设计了本试验。     

白菜雄性不育相关基因BcMF4基因功能的RNAi验证

BcMF4(Brassica campestris Male Fertility 4)是前一阶段从普通白菜 (Brassica campestris ssp. chinensis var. communis, syn. B. rapa ssp. chinensis var. communis)核雄性不育两用系的可育株中分离到的雄性不育相关基因。本研究根据BcMF4基因的cDNA序列设计两对特异引物, 从普通白菜花蕾cDNA中扩增出两个片断后连接至双元载体pBI12l中, 得到了RNAi (RNA interference) 植物表达栽体pBI-B4R, 并导入了农杆菌LBA4404菌株中; 通过组织培养途径转化菜心(B. campestris ssp. chinensis var. parachinensis), 72.2%的菜心转基因植株中45.8%的花粉为缩小而空瘪的畸形, 而且这些植株的花粉离体萌发率降低至23.7%; Northern杂交显示, 转基因植株的花粉畸形, 是由于BcMF4基因片段的插入使BcMF4基因的表达受到了抑制。结果表明, 采用RNAi技术下调了BcMF4基因的表达, 导致了菜心转基因植株部分花粉的不育, 证明BcMF4基因在普通白菜和菜心等白菜植物的花粉发育中起着重要作用。     

PP333对油菜种间杂种试管苗生长发育的影响

甘蓝型油菜(Brassica napus)品种Willi与埃塞俄比亚芥(B.carinata)F_4代种子,白菜型油菜(B.campestris)品种郫县早黄油菜和七星剑作母本与埃塞俄比亚芥杂交授粉后胚发育到手杖期的不饱满种子,用75％乙醇处理30s,再用0.2％HgCl_2浸泡12min,无菌水冲洗3次。甘蓝型作母本的组合接种在1/2MS大量元素和1/2MS附加不同浓度的PP333的液体和固体等7种培养基上。     

白菜OguCMS相关MYB家族新基因BcMYBogu的克隆与特征分析

为研究CMS核质互作的分子机理, 将甘蓝型油菜(Brassica napus L.)和白菜(B. campestris L. ssp. chinensis Makino)杂交并连续回交6代获得白菜OguCMS, 在与保持系花药细胞学比较的基础上, 运用cDNA-AFLP筛选得到白菜OguCMS早、中期花蕾提早表达的MYB-like差异片断, 利用RACE克隆得到该片断的cDNA全长, 命名为BcMYBogu(GenBank 登录号: EF127861), 对其氨基酸序列和表达特征进行研究。结果表明, 白菜OguCMS绒毡层在四分体后增生, 高度液泡化, 导致小孢子花粉外壁异常, 细胞质同外壁分离并降解; 花药变白; BcMYBogu具有典型的MYB DNA结合域—W残基和SH[AL]QKY[RF]基序; 系统进化分析显示BcMYBogu与AtMYB26, AtMYB32和AtMYB4等聚类在同一分枝; RT-PCR分析表明BcMYBogu在莲座叶、花茎和花蕾中均有表达, 但在OguCMS花蕾中表达量显著上升。由此推测BcMYBogu是一个新的与白菜OguCMS相关的MYB家族新成员。     

通过白菜型油菜和埃塞俄比亚芥的Ar和Cc基因组导入创造甘蓝型油菜新材料

油菜是目前我国主要种植的油料作物之一,但现有的种质资源限制了产量的进一步提高。本研究采取了一种新的育种方式来增加甘蓝型油菜的种质资源,即通过远缘杂交结合分子标记辅助选择的方式将白菜型油菜的Ar基因组和埃塞俄比亚芥的Cc对现有的甘蓝型油菜品种的基因组(AnAnCnCn)进行部分替换。通过对五倍体杂交后代(ArAnBcCcCn)进行染色体选择,找到了染色体数目为38的材料。为了和现有的甘蓝型油菜进行区分,得到的新材料被认定为甘蓝型油菜新材料。实验结果表明,得到的部分甘蓝型油菜新材料具有基本正常的减数分裂过程、正常的花粉萌发以及胚囊发育过程,这说明甘蓝型油菜新材料达到了遗传平衡。分子标记分析表明:甘蓝型油菜新材料的约50%的基因组被白菜型油菜的Ar基因组和埃塞俄比亚芥的Cc替换,并且这些甘蓝型油菜新材料之间具有丰富的遗传多样性。因此,白菜型油菜的Ar基因组和埃塞俄比亚芥的Cc基因组导入对于丰富现有的甘蓝型油菜种质资源具有明显的效果。     

改良菜心离体培养植株再生体系的研究(简报)

菜心(Brassica campestris L.subsp.chinensis Makino var.parachinensis Tsen et Lee)为十字花科芸薹属芸薹种中国白菜亚种中的一个变种,又名“菜薹”。它是我国南方特产蔬菜之一,在蔬菜的周年供应上有重要地位。目前迫切需要培育抗病虫、抗逆和具有其他优良农艺性状的新品种,以提高菜心的     

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.