Mechanism of Pollination in Gladiolus: Roles of the Stigma and Pollen-tube Guide

Gladiolus has a dry type of stigma. Compatible pollen grainsalight and germinate on the receptive surface of the papillae,penetrate the cuticle and grow towards the style through a sub-cuticularpollen-tube guide of mucilage. This is secreted from epidermalcells of the stylodium and style canal. The cuticle, which coversthe pollen tube guide mucilage, is continuous through the stylecanal to the ovary. The wet stigma of Lilium also has cuticulartissue running through the style canal, covering the mucilage.     

Pollen Tube Growth and Fertilization Efficiency in Salpiglossis sinuata: Implications for the Involvement of Chemotropic Factors

The possible involvement of chemotropic factors influencingpollen tube growth in the style and ovary of Salpiglossis wasstudied. Pollen deposited at the base of excised styles germinatedreadily, with pollen tubes penetrating the transmitting tissueand growing towards the stigma, implying that no chemotropicrequirement exists for pollen tube growth in the style. However,the position and high efficiency of seed set following limited-pollinationof intact pistils would support the involvement of localizedchemotropism operating within the ovary. Chemotropism, limited pollination, fertilization efficiency, Salpiglossis sinuata     

Interspecific Pollen-Pistil Interaction in Eucalyptus L'Her. (Myrtaceae): The Effect of Taxonomic Distance

The pollen-pistil interaction was investigated in three intraspecific,57 interspecific and six intergeneric crosses using three speciesof Eucalyptus (Myrtaceae) subgenus Symphyomyrtus, section Bisectariaas female parents Interspecific prefertilization isolation occursin the pistil and manifests as a number of pollen-tube abnormalitiesin the style and ovary associated with a lowered probabilityof ovule penetration The major selection points in the pistilare the upper style and the ovary The seventy of abnormalitiesand the probability of pollen-tube arrest in the pistil wasproportional to the taxonomic distance between parent speciesOvule penetrations were seen mainly in crosses within the sectionBisectaria or between the sections Bisectaria and Adnataria Pollen storage, style length and mean maximum temperature duringthe flowering period of the male parent had no significant effecton pollen-tube growth in the crosses used Mechanisms of reproductiveisolation are discussed in relation to evolutionary relationshipsand the implications for taxonomic groupings Eucalyptus L'Hér, pollen-pistil interaction, incongruity, interspecific hybridization, pollen-tube growth, breeding system, taxonomy     

烟夜蛾组织蛋白酶B酶原基因的克隆、序列分析和原核表达

利用反转录多聚酶链式反应（RT-PCR）技术从烟夜蛾Helicoverpa assulta (Guenée)雌虫卵巢中扩增得到了组织蛋白酶B酶原基因（cathepsin B,CB）cDNA片段,将其克隆至pMD19-T载体。测序结果表明, 该片段长度为1 017 bp,含有组织蛋白酶B酶原基因完整开放阅读框架（ORF）（GenBank登录号：EF154237）。序列分析结果显示：烟夜蛾组织蛋白酶B（HassCB）编码338个氨基酸残基,预测N-末端含有长度为21个氨基酸残基的信号肽序列;去除信号肽序列后,预测成熟蛋白分子量为35.5 kDa,等电点为5.96。氨基酸序列比对结果表明,HassCB与其他昆虫的组织蛋白酶B酶原氨基酸序列有较高的一致性。将去除信号肽序列的HassCB（HassCBa）重组到表达载体pGEX-4T-1中,并转入原核细胞中表达,SDS-PAGE和Western印迹分析表明：该基因能在大肠杆菌BL21中表达,电泳检测到一条大约61 kDa的目的条带,与预测的融合蛋白分子量相符。用该基因制备多克隆抗体并测得该抗体对重组表达的HassCBa的效价为1∶51 200。通过免疫印迹检测证实,此抗体既能识别重组表达的HassCBa,又能识别烟夜蛾卵巢匀浆液中的HassCB。     

The Anatomy, Histochemistry and Ultrastructure of Stigmas and Styles in Commelinaceae

The anatomy and ultrastructure of stigmas in 37 species of 13genera of Commelinaceae are described. The stigmas are papillate,papillae forming a dense fringe of cells around the mouth ofthe stylar canal in most species. The papillar cell wall iscovered by an unstructured cuticle of variable thickness andis of variable thickness because of small wall ingrowths. Thecuticle and the external surface of the papillar cell wall arevariably disrupted, particularly in the mid and basal regionsof the cell. This was not found in species of the genus Aploleiaor Callisia. The cell cytoplasm possesses all major organellesexcept chloroplasts and each cell is vacuolate. In all species except Aploleia mulitiflora the style comprisesan epidermis, a cortex and a hollow, tripartite canal whichis continuous into the ovary cavity. The three vascular strandsare positioned at the apex of each canal lobe. The canal cellsare elongate and tabular and the wall abutting the canal hasingrowths. The style in Aploleia is solid and the transmittingtissue comprises cells whose walls are electron opaque. Thecytoplasms of both types of cell are similar in content althoughthere is a single, large vacuole in canal cells and many smallvacuoles in transmitting tissue. The morphology, position and histochemistry of stigmatic andstylar exudate was similar in all ‘wet’ stigmas.Most of the exudate originates from the stylar canal althoughsignificant contributions are made by the papillae in stigmasof Coleotrype, Dichorisandra and Thyrsanthemum. There is no apparent relationship between stigma structure andthe presence of self-incompatibility. Stigma papillae, stylar canal, transmitting tissue, Commelinaceae     

Seed Set in Lotus berthelotii Masferrer

Self-pollination in L. berthelotii results in a very low seedset and so the species is considered to be self-incompatible.Pollen tubes have been observed in the ovary. The situationis complicated because ovules in individual ovaries possessembryo sacs at various stages of development from two-celledto eight-celled and this must affect the numbers of seeds whichset. Successful pollination requires rupture of the stigmaticcuticle. The conservation of L. berthelotii by seed propagation is possiblebut the genetic base of the species remains restricted. Lotus berthelotii stigma, style, self-incompatibility, seed set     

Pistil Structure and Pollen Tube Pathways in Leptospermum myrsinoides and L. continentale (Myrtaceae)

Pistil structure and pollen tube growth were investigated inLeptospermum myrsinoides and L. continentale (Myrtaceae). BothL. myrsinoides and L. continentale pistils consist of an ovarywith five locules, a style and a five-lobed dry, papillate stigma.A centrally located stigmatic cleft is present but extends onlyto the base of the stigma. Pollen germinates and grows intercellularlythrough the stigma into the central transmitting tissue of thestyle. Pollen tubes do not grow down the stigmatic cleft. Atthe base of the style the transmitting tissue separates intofive, each tract leading through the placenta to one of thefive locules. The pollen tubes continue to grow intercellularlythrough these five tracts entering the locules between the lobesof the placenta. Pollen tubes are smooth-walled and straightwhilst in the transmitting tissue of the style but produce shortlateral branches at regular intervals when in the locules. Branchingcontinues until pollen tubes enter ovules. It is suggested thatthe observed branching in the locules is a result of pollentubes following a chemotropic or thigmotropic pathway to theovules. This behaviour was consistent in all pistils examinedand no difference was observed in the behaviour of self- orcross-pollen tubes in the style or ovary.Copyright 1994, 1999Academic Press Leptospermum myrsinoides Schldl., Leptospermum continentale J. Thompson, pistil structure, pollen tube pathway, pollen tube branching     

Homeotic, Meristic and Cytological Floral Mutants of Thryptomene calycina (family Myrtaceae)

Twenty plants with various phenotypic abnormalities to the flowerswere selected from very large populations of Thryptomene calycinain the Grampian and Black Ranges. Most of these had impairedreproductive function. Normal flowers were epigynous with fivesepals, five petals, five anthers, a single style and two anatropousovules. The mutants were two partially male sterile, tetraploidplants with large flowers, one of which occasionally producedadditional flowers from the leaf axils with peduncles as wellas pedicels; one plant which produced a proportion of hexapetaloidflowers with six stamens; three gross mutants with fleshy, bracteoidpointed petals and sepals, no stamens, vestigial styles andstigmas, exposed ovules and no inferior ovary; one plant withfleshly, bracteoid pointed sepals, vestigial style and stigmabut with exposed ovular structures replaced by four to fivesterile ovules generally inside an abnormal ovary; two plantswith reduced ovary diameter and sterile ovules, shortened style,five reduced sepals and petals and five to eight anthers; threeanthocyanin-free plants; three plants with pink sepals; twoplants with half-sized flowers which produced a proportion offasciated stems; one plant which occasionally produced flowerswithout pedicels which virtually resulted in organs which wereleaf-flower composites; two plants which produced sepals andpetals which contained chlorophyll and prematurely senesced,and had partial substitution of petals by anthers.Copyright1993, 1999 Academic Press Thryptomene calycina, Myrtaceae, Victorian lace flower, floral mutations, mutants, homeotic, meristic, tetraploid, fasciation, male sterility, cut flowers     

Fruit Development in Bambarra Groundnut (Voandzeia subterranea)

Flowers of Voandzeia subterranea are positively geotropic andthis helps their entry into the ground. The ovary develops onlywhen it is on the surface of, or inside, the soil. The transformationinto fruit occurs in two stages: (a) definite development of pod, followed by (b) development of seed. The first stage occurs during the first 30 days after fertilizationand the second stage lasts for about 10 days. Maturity is characterizedby dryness and browning of the interior of the shell and appearanceof brown patches on it. The part of the pod on which the pedicelsubsists is the upper part and the lower part is the portionwhere the style is attached.     

The Pollen Tube Pathway in the Pistil of Lycopersicon peruvianum

The pollen tube pathway has been studied in unpollinated andpollinated pistils of Lycopersicon peruvianum using histochemicalstains for detection of proteins, lipids and arabinogalactansby bright-field microscopy, and decolourized aniline blue fordetection of pollen tubes by epifluoresence microscopy. Thepollen tube pathway is a continuous tract of mucilage from thestigma surface to the ovule micropyles, and is associated witha continuous tract of specialized, protein-rich transmittingcells comprising the stigmatic papillae, vertical files of stylartransmitting cells and the placental epithelium within the ovary.The superficial exudate of the stigma is hydrophobic and richin lipids. The mucilage of the style and ovary is hydrophilicand rich in arabinogalactans but low in proteins. Pollen tubesgrow between cells through the mucilage of the stigma and stylartransmitting tract, and across the surface of the placenta inthe ovarian mucilage. The structure of the junction of the stylartransmitting tract with the top of the ovary placenta assistseffective distribution of pollen tubes within the ovary. Lycopersicon, solanaceae, fertilization, pistil, pollen tube, pollination     

Pistil Receptivity and Pollen Tube Growth in Relation to the Breeding System of Eucalyptus woodwardii (Symphyomyrtus: Myrtaceae)

Pistil structure, stigma receptivity and pollen tube growthwere investigated in relation to seed set of Eucalyptus woodwardii.Self-pollination resulted in reduced capsule retention and seeddevelopment as compared with cross-pollination. The pistil consistedof an ovary with five locules, a long style with a canal extendingfor two-thirds of its length, and a papillate stigma. Therewas no change in style length with time after anthesis, butboth stigma secretion and ability to support pollen germinationand tube growth increased to reach a peak at 7 d. Pollen germinatedon the stigma surface and in the stylar canal, but most tubegrowth occurred intercellularly in the transmitting tissue surroundingthe canal. At the base of the style the pollen tubes split intofive groups following the transmitting tissue strands to theovary. Each group grew through a septum dividing two loculesand entered the placenta. The tubes then emerged from the placentato penetrate the ovules at between 10 and 20 d after pollination.Fewer ovules were penetrated following self- than cross-pollination. Eucalyptus woodwardii Maiden, Lemon-flowered gum, Pistil receptivity, Pollen tube growth, Breeding system, Self-incompatibility     

两近缘种烟草上棉铃虫种群适合度的比较研究

分别在室内和自然条件下,比较研究了普通烟草和黄花烟草两种不同寄主植物上棉铃虫生长发育、食物转化和利用及种群增长情况。结果表明： (1) 室内26±1℃、75%±5% RH和16L∶8D光周期条件下,与普通烟草相比,黄花烟草上幼虫的发育历期显著延长,1龄和2龄幼虫的存活率及雌蛾产卵量显著下降,种群净增殖率（R₀=30.5374）和内禀增长率（r_m=0.0951）减小;(2) 6龄幼虫对两种烟草的近似消化率及其相对生长率无显著差异,但对黄花烟草的利用率和转化率显著下降,相对取食量显著提高;(3) 第2代棉铃虫在普通烟田的种群增长（I=1.9922>1）比黄花烟田（I=1.1581>1）快,“烟草和其他”对种群起主要控制作用,特别是对低龄幼虫;第3代棉铃虫在普通烟田的种群增长有所减慢但仍呈上升趋势（I=1.5994>1）,而在黄花烟田则呈下降趋势（I=0.6434<1）,低龄幼虫受烟草抗性和雨水等的影响较大,高龄幼虫被病菌感染的数量增多。这些结果表明,与普通烟草相比,黄花烟草不适合棉铃虫种群的增长和繁殖。     

The Carpel of Moringa

The gynoecium of Moringa is tricarpellary, syncarpous and unilocularwith parietal placentation. The three carpel primordia ariseindependently but soon become connected resulting in an annularstructure which develops into the tubular gynoecium. The gynoeciumis supplied with three dorsal and three marginal bundles. Thelatter represent the fusion product of the marginal bundlesof adjacent carpels and each splits into three in the ovarywall. The ovules receive their vascular supply from a commonbundle, which branches from the dorsal trace of the carpel atthe base of the ovary. The derivation of the gynoecium fromconduplicate carpels is postulated. Moringa oleifera, carpel morphology, conduplicate carpel, carpel ontogeny     

The Generic Position of Protorhus namaquensis Sprague (Anacardiaceae): Evidence from Fruit Structure

In Protorhus namaquensis the outer epidermis of the ovary formsthe exocarp. At maturity it is uniseriate and consists of palisade-likeparenchyma cells and modified stomata (MS). A cuticle, extensivecutinization of the outer cell walls and starch also characterizethe exocarp. The mesocarp develops from the ground tissue ofthe ovary wall and includes an outer zone of large-celled tanniniferousparenchyma, secretory ducts associated with some of the vascularbundles, prismatic crystals of calcium oxalate and brachysclereids.The inner epidermis of the ovary undergoes successive periclinaldivisions whose derivatives form the mature endocarp. It isstratified and tetraseriate, comprising successive layers (frommesocarp inwards) of crystalliferous cells, brachysclereids,osteosclereids and macrosclereids. The morphology of the femaleflower, and the fruit structure of P. namaquensis are comparedwith that of P. longifolia (lectotype of the genus and onlyother African species) and species of Ozoroa. We present abundantevidence that P. namaquensis should be associated with somemembers of the genus Ozoroa , rather than with P. longifolia.The new combination, Ozoroa namaquensis (Sprague) Von Teichman& Van Wyk, is proposed. Characters of the perianth and pericarp,inter alia the occlusion of the pores of most MS, are consideredadaptations of the species to its harsh semi-desert habitat.Copyright1994, 1999 Academic Press Anacardiaceae, Protorhus namaquensis, Ozoroa namaquensis, pericarp, fruit, flower, modified stomata, ontogeny, histochemistry, cutin     

A Novel Superoxide Dismutase Gene Encoding Membrane-bound and Extracellular Isoforms by Alternative Splicing in Caenorhabditis elegans

We have identified a novel Cu/Zn superoxide dismutase gene (termedSOD-4) in Caenorhabditis elegans. Characterization of its complementaryDNA revealed that the gene encodes two isoforms by alternativesplicing, SOD4-1 and SOD4-2 which differ in their C-terminalexons. Their predicted amino acid sequences include a consensussignal peptide at their N-termini and are homologous to theextracellular-types of Cu/Zn superoxide dismutase in mammals.In addition, SOD4-2 possesses a putative transmembrane domainat the C-terminal region. When transiently expressed in Chinesehamster ovary cells, both types were found in the membranesand SOD4-1 also in the culture fluid. It is, therefore, indicatedthat SOD4-1 is an extracellular form and SOD4-2 a membrane-boundform, the latter representing a novel type of SOD. In C. elegans,SOD4-2 mRNA was found to be preferentially expressed in eggs.     

感染稻水象甲的Wolbachia基因组中插入序列的鉴定与分析

共生细菌Wolbachia对宿主的生殖起多种调控作用。以往研究表明, Wolbachia基因组中广泛存在插入序列(insertion sequence, IS), 它们对宿主基因组的可塑性、 多样性和进化起重要作用。稻水象甲Lissorhoptrus oryzophilus Kuschel在东亚是一种外来水稻害虫, 在原产地北美营两性生殖, 而在所有入侵地均营孤雌生殖。本研究采用PCR法从河北唐海孤雌生殖型稻水象甲体内克隆获得了Wolbachia的2条IS序列, 即ISWosp4和ISWosp6; 从美国德克萨斯州两性生殖型稻水象甲成虫体内克隆获得了Wolbachia的2条IS序列, 即ISWosp3和ISWosp5。碱基序列比对显示: ISWosp3和ISWosp4属于IS3家族IS3组成员, ISWosp5为IS4家族IS231组成员, ISWosp6为IS5家族IS1031组成员。对这些IS的ORF结构、 所编码氨基酸序列的结构等进行了分析, 推测ISWosp5具有潜在转座活性。所得结果增进了我们对Wolbachia IS3, IS4和IS5家族插入序列的认识, 同时为今后从IS的角度探讨Wolbachia与稻水象甲生殖的关系奠定了基础。     

虫酰肼及其衍生物0593对家蚕的毒性及作用机理

为明确虫酰肼衍生物0593对家蚕Bombyx mori的毒性,本研究采用食下毒叶法测定了虫酰肼及其衍生物0593对家蚕的毒性,观察了亚致死浓度下对家蚕生长发育的影响,并测定了虫酰肼及其衍生物0593对家蚕幼虫体内保护酶的影响,对虫酰肼0593的作用机理进行了初步探索。结果表明：虫酰肼及其衍生物0593对2龄家蚕96 h的LC₅₀值分别为1.2863和0.3364 mg·L^-1,属高毒级药剂;虫酰肼及其衍生物0593在亚致死剂量下对家蚕的生长发育有明显的不利性,可使幼虫历期缩短0.5～2 d;处理组眠期体重、全茧量、蛹重和化蛹率与对照相比均显著降低;对4龄幼虫体内多酚氧化酶和几丁质酶也有较明显影响,虫酰肼及其衍生物0593处理家蚕,处理后6 h对体内多酚氧化酶有明显激活作用,12 h后表现出显著的抑制作用;虫酰肼及其衍生物0593对家蚕体内几丁质酶均有激活作用。0593对保护酶的影响较虫酰肼明显。结果提示虫酰肼及其衍生物0593对家蚕毒性高,对其生长发育和保护酶类均有不利性,不适合在桑园及其周边农田使用。     

Pistil Exudate Production and Pollen Tube Growth in Lilium longiflorum Thunb.

Exudate production in the pistil of Lilium longiflorum was studiedin relation to pollen tube growth, using scanning electron microscopy(SEM), transmission electron microscopy and light microscopy.In contrast with conventional fixation for SEM, during whichthe exudate of L. longiflorum largely washes away, the exudateremains present through freezing in case of cryo-SEM. Usingthe latter method we observed that exudate production on thestigma and in the style started before anthesis. Just underneaththe stigma the exudate was first accumulated at the top of eachsecretory cell, followed by a merging of those accumulationsas exudate production proceeded. Exudate is also produced bythe placenta. It was however not possible to determine whetherany of this fluid originated from the micropyle. Apart fromthe cell shape and the cuticle present in between the secretorycells, the ultrastructure of the secretory cells covering theplacenta was comparable to those of the stylar canal. The transferwall of the secretory cells of the placenta originated fromfusing Golgi vesicles but the endoplasmic reticulum seemed tohave an important role as well. After pollination the pollen tubes grew across the stigma andentered the style through one of the slits in the three stigmalobes. The pollen tubes grew straight downward through the styleand were covered by exudate. As the pollen tubes approachedthe ovary their growth was restricted to the areas with secretorycells. In the cavity the pollen tubes formed a bundle and theybent from this bundle in between the ovules towards the micropylarside. There they bent again to stay close to the secretory cells.After bud pollination the pollen tube growth was retarded. Laterarriving pollen tubes had a tendency to grow close to the secretorycells of the style, which resulted in a growth between thesecells and preceding pollen tubes. If there was still a littleexudate produced, it resulted in a lifting up of the pollentubes, out of the exudate. The relationship between exudateproduction and pollen tube growth is discussed. Both the speedand the guidance of the pollen tube seemed determined by theproperties of the exudate.Copyright 1994, 1999 Academic Press Cryo-scanning electron microscopy, exudate, Lilium longiflorum, lily, ovary, pollination, pollen tube growth, secretory cell, stigma, style     

The Ovule and 'Seed' of Araucaria Bidwillii with Discussion of the Taxonomy of the Genus: III. Anatomy of Multi-ovulate Cone Scales

This paper deals with the anatomy of two- and three-ovulatecone scales which are found occasionally in the cones of A.Bidwillii. The manner in which each ovule receives its vascularsupply from bundles lateral to the ovule is discussed, togetherwith a hypothetically primitive type of araucarian cone scalewith three ovules possibly resembling the fossil Schizolepis.The interpretation of the vascular system of the scales as givenin this paper is a correction of that presented in the firstpaper of this series by the same authors.     

大豆蚜细胞色素氧化酶Ⅱ基因的克隆及其在捕食性天敌昆虫鉴定中的应用

利用通用引物,对大豆蚜Aphis glycines Matsumura的细胞色素氧化酶Ⅱ（COⅡ）基因序列进行克隆和测序。测得的序列长度为810 bp,并与已在GenBank上登录的其他蚜虫COⅡ基因序列进行比较分析,验证其同源性,同时将该序列在GenBank进行了登记 (登录号为DQ265743)。根据此片段的碱基序列设计了1对大豆蚜特异引物,其扩增片段约为270 bp;种特异性检验结果表明,该引物只对大豆蚜具有扩增能力,对其他相关蚜虫种类不具有扩增效果;并用此引物对大豆蚜捕食性天敌进行定性检测,结果表明,在取食过大豆蚜的异色瓢虫Harmonia axyridis、龟纹瓢虫Propylaea japonica、大草蛉Chrysopa septempunctata幼虫以及小花蝽Orius similes 成虫和幼虫等捕食性昆虫的中肠中均能检测到大豆蚜的DNA片段; 而在未取食蚜虫的上述天敌中却未能扩增出来。