水稻孢子体细胞质雄性不育系线粒体DNA的RAPD分析

利用200个10nt随机引物对水稻孢子体细胞质雄性不育系珍汕97A、保持系珍汕97B、F1代汕优63、恢复系明恢63和另一种孢子体细胞质雄性不育系马协A、保持系马协B、F1代马协63的线粒体DNA进行PCR扩增。在36℃的退火温度下,有132个引物扩增出了清晰的、重复性较好的条带。同一组合内的不育系同保持系、恢复系之间线粒体DNA随机引物扩增产物的多态性明显高于不育系与F1代。不育系与F1代线粒体DNA的扩增产物也存在多态性。一些特异性的差异片段可能与水稻CMS相关。     

BT型细胞质雄性不育水稻及其三系的线粒体DNA研究

用RAPD技术对BT型水稻胞质雄性不育系秀A及其保持系秀B、恢复系湘晴以及杂种F1代的线粒体DNA进行了比较分析。结果表明不育系与其保持系间存在显著差异;不育系与其F1之间mtDNA也存在差异。在引物OPJ－08的扩增产物中,秀A扩增出一条分子量为800bp的多态性片段,在引物OPK－10的扩增产物中,杂种F1扩增出一条分子量为900bp的片段。把这两片段回收、克隆并制备探针,OPJ－08800的Southern杂交结果显示不育系与其F1杂交图谱存在多态性;OPK－10900的Suthern杂交结果显示不育系与其保持系同存在差异。推测这两片段与育性可能有一定的联系。     

粘类小麦细胞质雄性不育基因的初步研究

许多细胞质雄性不育(CMS)基因涉及ATP合成酶基因或细胞色素氧化酶基因的片段,该研究选用‘中国春'小麦(Triticum aestivum)的atp1+atp9、atp6、atp8、cox2、cox3、nad9和T型小麦不育系的orf256基因片段作探针,对粘类小麦不育系、保持系、恢复系及其F1进行Northern杂交分析,以探寻粘类小麦不育系的CMS候选基因.结果发现,atp6在4种粘类不育系中的转录本大于保持系;cox3在4种不育系中的转录本小于保持系.由此推测atp6或cox3基因可能参与了粘类小麦CMS的形成.     

油菜细胞质雄性不育系叶绿体DNA特异片段的分子克隆

采用高离子浓度缓冲液法分别提取油菜不育系及保持系的叶绿体DNA。经Sepharcse 4B柱层析纯化后,得到具有较高纯度的叶绿体DNA样品。将其分别用Eco RI、Bam HI、HimdHI、PstI和XhoI 5种限制性内切酶酶解,得到5种限制性内切酶图谱。其中除PstI图谱外,其它4种酶谱均显示出明显的两系间叶绿体DNA结构差异。以pBR 322为载体,分别克隆了不育系Bam HI图谱上的3个特异片段。得到的3个克隆,经克隆杂交及电泳分析后,证实分别带有上述3个目的片段。这些特异片段的特性及其与花粉育性的关系尚在研究中。     

苎麻atp6和atp9基因的克隆表达及与细胞质雄性不育的相关性

摘要: 根据GenBank报道的双子叶植物线粒体atp6和atp9基因编码区保守序列设计简并引物, 通过PCR技术从苎麻细胞质雄性不育系、保持系和恢复系(简称“三系”) mtDNA中扩增目的基因片段, 发现所得序列开放阅读框虽不完整, 但与GenBank报道的其他植物线粒体atp6和atp9基因同源性分别高于94%和85%。采用DNA Walking步移法分别从3′端和5′端扩增两个基因片段的未知侧翼序列, 分离出完整的苎麻线粒体atp6和atp9基因, 包含了完整的开放阅读框。其中“三系”的atp6基因在mtDNA水平、转录和翻译调控水平、蛋白质水平上均无差异。不育系atp9基因在编码区3′端与保持系和恢复系相比存在若干个碱基的差异和缺失; RT-PCR分析还表明, 不育系atp9基因在现蕾期和盛花期的表达量很高。推测不育系atp9基因的结构变异和/或异常表达与苎麻细胞质雄性不育(CMS)的关系密切。     

红麻MYB21基因的克隆、表达及载体构建

克隆红麻不育系和保持系的MYB21基因,分析MYB21基因在红麻不育系和保持系各器官的表达量,并构建过表达载体和RNAi载体,旨在为进一步研究该基因在红麻中的功能奠定基础。以同源克隆的方法克隆MYB21基因;用实时荧光定量的方法分析MYB21基因在红麻不育系和保持系不同组织器官的表达模式;根据酶切-连接的方法,构建过表达载体和RNAi载体。结果显示,红麻MYB21基因在不育系和保持中的基因序列没有差异,其c DNA全长序列为922 bp,包含843 bp的开放阅读框,DNA全长序列为1 108 bp,包含3个外显子和2个内含子(NCBI序列登录号为KT898146);MYB21基因主要在花药中表达,在不育系和保持系花药之间表达量呈极显著差异;成功构建MYB21过表达载体和RNAi载体。成功克隆MYB21基因的全长序列;实时荧光定量结果表明MYB21基因主要在花药中进行表达;构建的植物过表达载体PBI121-MYB21和RNAi载体p ART27-PK-R1-F2可用于该基因的功能研究。     

高粱七种胞质恢保体系的创新与利用

通过6年10代南北育种,对征集的1000份国内外种质资源、育种试材进行大量测交育性鉴定,建立了A1至A7七种胞质恢保体系,进一步拓展和丰富了高粱杂种优势利用的基因型范围,培育出A1至A7七种胞质雄性不育系30多个系列和新胞质杂交种.通过对A1、A2、A3、A5、A6型五种胞质不育的育性恢复基因的遗传机制的研究,找到了A1、A2、A5、A6胞质不育恢复基因的差异和有许多共同恢复系和保持系的原因.研究并分析了A3胞质不育杂交种F2分离比率和A3不育系育性恢复基因的遗传方式,发现了A3胞质不育系小花不败育,培育出矮秆、穗大粒多、配合力强、育性又非常稳定的一批A3型不育系.找到了优点多、实用价值大、长期科学实践中难恢复的不育系--A3不育系的恢复系,进一步配制出A3杂交种并转育了一大批A3恢复系后代材料.     

高粱七种胞质恢保体系的创新与利用

通过6年10代南北育种,对征集的1000份国内外种质资源、育种试材进行大量测交育性鉴定,建立了A1至A7七种胞质恢保体系,进一步拓展和丰富了高粱杂种优势利用的基因型范围,培育出A1至A7七种胞质雄性不育系30多个系列和新胞质杂交种。通过对A1、A2、A3、A5,A6型五种胞质不育的育性恢复基因的遗传机制的研究,找到了A1、A2、A5、A6胞质不育恢复基因的差异和有许多共同恢复系和保持系的原因。研究并分析了A3胞质不育杂交种F2分离比率和A3不育系育性恢复基因的遗传方式,发现了A3胞质不育系小花不败育,培育出矮秆、穗大粒多、配合力强、育性又非常稳定的一批A3型不育系。找到了优点多、实用价值大、长期科学实践中难恢复的不育系——A3不育系的恢复系,进一步配制出A3杂交种并转育了一大批A3恢复系后代材料。     

K、V、T型小麦细胞质雄性不育系叶绿体DNA的SSR分析及RuBP羧化酶活性比较

为了探讨小麦细胞质雄性不育(CMS)与叶绿体DNA(cpDNA)的关系,揭示CMS机理。以2套K、V、T型同核异质不育系(A)及其保持系(B)‘太911289’和‘冀5418’、育性恢复的F_1和各自的质供体粘果山羊草(Aegilops kotschyi)、偏凸山羊草(Aegilops ventricosa)、提莫菲维小麦(Triticum timopheevii)为试验材料,利用cpSSR引物对小麦cpDNA进行比较分析,筛选出代表不同胞质不育系的引物,探讨CMS与叶绿体的关系;同时测定由叶绿体DNA与核DNA共同编码的RuBP羧化酶的活性,为小麦K、V、T雄性不育类型的应用提供理论依据。结果表明:(1)K型、V型、T型不育系与保持系的cpDNA之间均呈现多态性,且不同的细胞质之间存在特异片段,这从DNA水平上提供了3类不育系胞质来源不同的证据,并分别找到5对和7对可以鉴定V型和T型不育系的特异引物。(2)除K型‘冀5418’与其胞质供体的cpDNA出现差异外,不育系与其胞质供体的cpDNA没有差异,而且不育系与其育性恢复的F_1代cpSSR扩增片段之间也没有差异,很好地遗传了其母本性状。(3)在起身期和开花期,不仅2套不育系的RuBP羧化酶活性显著高于保持系,且在不育系与恢复系杂交的F_1中,随着育性的恢复其RuBP羧化酶活性高于保持系而低于各自不育系;而在拔节期的不育系与保持系之间、不育系之间、以及F_1代与不育系和保持系之间的RuBP酶活性大小没有显著差异。这可能与拔节期主要是营养生长有关系。     

水稻两种细胞质雄性不育“三系”及其F1杂交种线粒体DNA的RFLP分析

对水稻BT型和WA型细胞质的雄性不育系,相应保持系和恢复系以及杂种的mtDNA用12个线粒体探针进行了RFLP分析,结果如下(1)BT型和WA型不育系的mtDNA在组织结构上存在差异;(2)不育系的mtDNA与其保持系间存在显著差异,推测mtDNA与水稻的cms有关;(3)atp9探针检测到WA型不育系与F1之间的多态性,Frag36探针检测到BT型不育系与F1之间的多态性,Frag9探针检测到WA型和BT型不育系与其F1之间的多态性,证明核恢复基因影响mtDNA的结构;(4)对mtDNA的结构变异与细胞质雄性不育的关系进行了分析与探讨.     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.