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1.
Rostromysis bacescuii gen. et sp. nov. and Megalopsis denlicaudagen. et sp. nov. belonging to the tribe Leptomysini are describedfrom the south-west coast of Australia. The characters uniqueto the genus Rostromysis are the unusually long club-shapedrostrum and the large delicate lamella-like pleopods of thefemale, thus easily distinguishing it from the allied generaTenagomysis and Doxomysis. The genus Megalopsis is closely alliedto Leptomysis, Prionomysis and Promysis but is readily distinguishablein having a short linguiform uncleft telson with a pair of medianplumose setae.  相似文献   

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3.
Floral biology and pollination mechanism of theAcaciahybrid(A. mangiumWilld. xA. auriculiformisA. Cunn. ex Benth.) growingin Thailand are investigated using light and electron microscopy.The hybrid is andromonoecious. A floral spike consists of about150 loosely arranged flowers. Flowers are cream coloured, fragrantand have no floral nectaries. The pistil has a solid style witha smooth, wet stigma and amphitropous ovules with immature integuments.The anther consists of eight loculi, each bearing only one 16-grainpolyad. The flowers are weakly protogynous. Anthesis is completeat 0500–0600 h but peak female receptivity begins at 0200–0300h and is completed that day. The stigmatic exudate is of thelipophilic type and is secreted from the stigmatic cells bya holocrine mechanism. Pollen is the main floral reward forthe insect pollinators. There are several floral characteristicswhich facilitate pollen transfer from anthers and depositionon stigmas.Apis melliferaandCeratinasp. are the most effectivepollinators because they are the most common visitors and carrya heavy load of hybrid polyads. However, their behaviour inforaging for pollen in the same tree and weak protogynous dichogamymay promote self-pollination in the hybrid. The hybrid has lowpollination success due to low pollinator number. An increasein exposure time of flowers to pollinators or pollinator numbermay increase pollination success but may not affect the rateof pollen deposition on stigmas due to the relatively smallsize of the stigma in relation to the polyad.Copyright 1998Annals of Botany Company Acaciahybrid,Acacia mangium, Acacia auriculiformis, pollination, pistil receptivity, anthesis, pollinators.  相似文献   

4.
The habitat, diet, some reproductive and mortality factors forseveral shallow-water species of the boreal turrid genus Oenopotafrom the Puget Sound region were determined. All fed exclusivelyon tubicolous polychaetes. Oenopota fidicula was a dietary andhabitat generalise Oenopota elegans eats Schistocomus hiltoniand lives in areas of shell fragments. Oenopota excunata eatsTharyx multifilis and is a habitat generalist. Oenopota tabulataappears to be a dietary generalist, but lives only on or nearrocks. The widely-distributed species, O. levidensis, eats spionidpolychaetes, primarily Polydora species, or Owenia fusiformis,and is a habitat generalist. Feeding frequencies are low asare population densities; although O. levidensis sometimes exceeds15 animals m–2. Crabs are major predators upon turridsin some areas, but mortality causes are generally obscure. Spawningwas observed in four species, but only O. elegans and O. levidensishad viable larvae. Development takes 13–15 weeks, 6–7weeks in a capsule and 6–7 weeks as planktonic veligers.There are no nurse eggs. Settling was not observed. *Present mailing address: Bamfield Marine Station Bamfield,B.C. VOR 1B0 CANADA (Received 30 May 1982;  相似文献   

5.
中国隧蜂属研究及新种新亚种记述(膜翅目:隧蜂科)   总被引:1,自引:0,他引:1  
皮.  尤阿吴燕如 《昆虫学报》1997,40(2):202-206
中国隧蜂属Halictuss.sir.的研究是根据Pesenko的分类系统撰写的[1,2]。有关中国隧蜂属的第1篇报道是Morawitz[3]记述由俄罗斯N.M.Przewalsky1877年采自天山的Halictusquadricinctus及H.resurgens(名为H.sexcinctussensuMorawitz),1890年Morawitz又增加两种[4],即H.tetrazonicus(部分应为H.tsintouensis)及H.rubicundus,该两种是G.N.Potanin于1886年采自甘肃(标签上误写为蒙古“Mongolei”,详见Pesenko中国及蒙古隧蜂属的讨论[5])。Strand也记述了中国的种类[6,7],其1909年的文章中记述了中国西部(“Jarkand”…  相似文献   

6.
Background and Aims: Gross vegetative and floral morphology, as well as modern moleculartechniques, indicate that Cryptocentrum Benth. and SepalosaccusSchltr. are related to Maxillaria Ruiz & Pav. However, theydiffer from Maxillaria in their possession of floral spurs and,in this respect, are atypical of Maxillariinae. The labellarmicromorphology of Maxillaria, unlike that of the other twogenera, has been extensively studied. In the present report,the labellar micromorphology of Cryptocentrum and Sepalosaccusis compared with that of Maxillaria and, for the first time,the micromorphology of the floral spur as found in Maxillariinaeis described. Methods: Labella and dissected floral spurs of Cryptocentrum and Sepalosaccuswere examined using light microscopy (LM) and scanning electronmicroscopy (SEM). Key Results: In each case, the labellum consists of a papillose mid-lobe(epichile), a cymbiform region (hypochile) and, proximally,a spur, which is pronounced in Cryptocentrum but short and bluntin Sepalosaccus. The inner epidermal surface of the spur ofCryptocentrum is glabrous or pubescent, and the bicellular hairs,where present, are unlike any hitherto described for Maxillariinae.Similar but unicellular hairs also occur in the floral spurof Sepalosaccus, whereas the glabrous epidermis lining the spurof C. peruvianum contains putative nectar pores. Conclusions: The labellar micromorphology of Cryptocentrum and Sepalosaccusgenerally resembles that of Maxillaria. The floral spur of Cryptocentrumdisplays two types of organization in that the epidermal liningmay be glabrous (possibly with nectar pores) or pubescent. Thismay have taxonomic significance and perhaps reflects physiologicaldifferences relating to nectar secretion. The trichomes foundwithin the spurs of Cryptocentrum and Sepalosaccus more closelyresemble the hairs of certain unrelated, nectariferous orchidtaxa than those found in the largely nectarless genus Maxillaria,and this further supports the case for parallelism.  相似文献   

7.
YI-BO  LUO; ZHEN-YU  LI 《Annals of botany》1999,83(5):489-499
Flowering and pollination biology ofChloranthus serratusandChloranthusfortuneiwere studied. Flowering took place from early Marchto mid–April inCh. fortunei, and from April to September,the whole growth period, inCh. serratus.The flowering periodof an inflorescence ofCh. serratusaveraged about 8 d and anthesisof a single flower was 5–6 d. Flowers are slightly protogynous.The flower emitted fragrance when the androecium became white.Both species are entomophilous with thrips as exclusive pollinators.Under natural conditions, fruit set occurs mainly as a resultof cross-pollination, but self-pollination and agamospermy mayoccur in some cases. In flowers ofCh. fortuneiandCh. serratus,theincurved androecium, the carpel and the spike axis form a nearlyclosed chamber that contains the anthers and stigma. The developmentof a floral-axial chamber may be an important step towards amore economical and effective pollination system. Floral morphology,pollination biology and fossil evidence suggest that the mainevolutionary trend in the genusChloranthusis towards developmentof ‘closed’ flowers. The fidelity of the relationshipbetweenChloranthusand thrips is regarded as a specialized featureof pollination biology and this relationship may have originatedearly in the evolutionary lineage.Copyright 1999 Annals of BotanyCompany Chloranthaceae,Chloranthus, Thysanoptera,flowering, floral-axial chamber, pollination, evolution trends.  相似文献   

8.
Epacris crassifolia R. Br.s. lat.,as represented in collectionsat G, BM, HO, NSW, MEL, CBG and CAN, has been redefined as threeseparate species. The common lax, prostrate form includes twosubspecies,E. crassifoliassp.crassifoliaR. Br.stat. nov. andE.crassifoliassp.macrofloraCrowden et Menaduessp. nov.separatedon floral morphology.E. pinoideaCrowden et Menaduesp. nov.andE.lithophilaCrowden et Menaduesp. nov.are erect and woody, beingdistinguished on leaf and floral characters. Epacridaceae; Epacris crassifolia ; Epacris lithophila; Epacris pinoidea; new species  相似文献   

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Stentor is a heterolrich ciliate which often forms lawn-likecovers on the bottom and/or blooms in the pelagial of lakesworldwide. The species involved in these spectacular eventswere usually either not determined or misidentified becausethe keys are outdated and incomplete. Thus, we have revisedthe nominal species described since the first major revisionby Ehrenberg (1838). Main species characteristics are the presence/absenceof symbiotic algae, the shape of the macronucleus and the colourof the cortical pigment granules. The last character mentionedmust be studied in live cells because the pigment bleaches inchemically fixed specimens. Nineteen valid species are recognizedand dichotomously keyed according to these characteristics.Twenty-seven other species and varieties, described after Ehrenberg'srevision, are synonyms or species indeterminata A new species.S.araucanus, is described from South American lakes. It is asmall, broadly trumpet-shaped Stentor with symbiotic algae,vermiform macronucleus and blue-green cortical granules. Stentoraraucanus is probably euplanktic and restricted to the southernhemisphere. Stentor auriculalus Kahl. 1932 sensu Wang (1934)is recognized as a new species, Condylostoma wangi, and transferredto the genus Condylostoma. New nomenclatural corrections: Stentorbaicalius nom. nov. (pro S.pygmaeus, preoccupied). S loricatiisnom. corr. (for S.loricata), S.ruber nom. corr. (for S.ruhra).  相似文献   

11.
The oil palm of commerce, Elaeis guineensis (tenera), derivesfrom hybridization of variety dura x pisifera. Germ plasm ofpisifera is limited, however, because of varying degrees offemale sterility. Efforts to increase the range of availablepisifera male germ plasm have thus far been limited to fertilepisiferas but it is anticipated that clonal multiplication ofembryos and explanted organs from less female-fertile, but nonethelessfertile, male, plants could play a significant role in breedingprogrammes. Callus has been produced from mature pisifera embryosand leaf explants from young plantlets using a half-strengthMurashige and Skoog medium supplemented with inositol, caseinhydrolysate, activated charcoal and varying concentrations ofauxins. After sub-culture on media of similar composition, organizedstructures can develop. Those which form in stale nutrient media(e.g. left in the same medium for up to 3 months) give riseto embryonal structures which do not readily develop furtherand can be regarded as neomorphs. If callus once formed is transferredto media with lower auxin concentrations (40–0 mg l–1)embryonal buds and well-formed shoots are produced; additionof gibberellic acid (GA3) fosters the production of well-organizedshoots accompanied by roots. Elaeis guineensis var pisifera, oil palm, tissue culture, micropropagation, embryo development, morphogenetic potential, callus  相似文献   

12.
Sideritis rodriguezii Borja is a natural hybrid between S.serrata Lag and S. bourgaeana Boiss. The hybrid index is usedto separate parentals, F1 hybrids and the individuals producedby back-crossing. Hybridization takes place in a hybrid zone100 m long 200 m wide. Two groups of hybrids were recorded,the first resembling S. bourgaeana and the second being morphologicallyintermediate between the parents. Hybrids are abundant in clumps,with higher densities in which both parents grow close together. Sideritis serrata Lag, Sideritis bourgaeana Boiss, hybridization, hybrid zone, S.E. Spain, hybrid index  相似文献   

13.
CORNER  E. J. H. 《Annals of botany》1953,17(2):347-368
1. The following noveltiea are described, with notes on otherspecies of their genera : Aphelaria subgen. Tremellodendropsis for the A. tuberosa alliancewith subtremellaceous basidia: A. amboinensis (Lév.)comb. nov. Chaetotyphula gelatinosa sp. nov. and C. tetraspora sp. nov.from Tropical America, whence C. hyalina (Jungh.) Corner isalso recorded. Clavariadelphus junceus (Fr.) Corner is recorded from Brazil. Mucronella flava sp. nov. from Iowa. Phaeoapheloria austra1iensis gen. et sp. nov. is intermediatebetween Aphelaria and stereoid fungi. Pistillaria trispora sp. nov. from Iowa: P. tucumanensis (Speg.)comb. nov. for Typhula tucumanensis Speg. Phistillina calyx Heim is excluded as marasmioid. 2. The Physalacria-subseriea is reviewed, and the followingare described aa new: Hormomitaria albidula sp. nov. from Brazil Pseudotyhula gen. nov. from West Africa: P. ochracea sp. nov.as the typespecies : P. tenuipes (Lloyd) comb. nov. (= Mucronellatenuipes Lloyd).  相似文献   

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15.
Structural features of the mature root cortex and its apoplasticpermeability to dyes have been determined for two dicotyledonouswetland plants of differing habitats: Nymphaea odorata, growingrooted in water and mud, and Caltha palustris, growing in temporalwetlands among cattails. In mature roots, movement of the apoplasticdyes, berberine and safranin, into the roots was blocked atthe hypodermis, indicating the presence of an exodermis. A hypodermiswith an exodermis, i.e. Casparian bands in the outermost uniseriatelayer plus suberin lamellae, is present in both species. InN. odorata, hypodermal walls are further modified with cellulosicsecondary walls. Roots of N. odorata and C. palustris have anendodermis with Casparian bands only. A honeycomb aerenchymais produced by differential expansion in N. odorata and includesastrosclereids and diaphragms, while roots of C. palustris haveno aerenchyma, but some irregular lacunae are found in old roots.These aspects of cortex structure are related to an open meristemorganization, with unusual patterns of cell divisions in certainground meristem cells (called semi-regular hexagon cells) ofN. odorata. The correlation between aerenchyma pattern and hypodermalstructure appears to be related to habitat differences.Copyright2000 Annals of Botany Company Caltha palustris, Nymphaea odorata, root development, cortex, endodermis, aerenchyma, exodermis, hypodermis, permeability, wetland plants  相似文献   

16.
CORNER  E. J. H. 《Annals of botany》1952,16(2):269-291
The genera Allantula (one sp.) and Parapterulicium (two spp.)are described from Brazil. The first has decumbent, cystidiateand unbranched fruit-bodies. The second has gloeocystidia anddichophyses, neither of which have yet been recorded in Pteruloidgenera. In the revision of Deflexula, ten species are recognized, fourbeing transferred from Mucronella and Pterula, and three beingdescribed as new, namely, D. major, D. mangiformu, and D. sulcispora.  相似文献   

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18.
Three new species are described, Paranchialina secunda. Leptomysislongisquama and Doxomysis johnsoni from the coastal waters ofSouth West Australia.  相似文献   

19.
A silicified stem from the Ischigualasto Formation (Trias) innorthern Argentina, is described and named Michelilloa waltoniinov. gen. et spec. It is compared with fossil stems of the generaCycadeoidea and Bucklandia, and with the living Cycadales. Acombination of characters (in particular the indumentum of longfilamentous hairs, multiseriate bordered pitting of the xylemtracheids, and the structure of the leaf gap and leaf tracebundle which are exactly similar to those of the cycad Dioonspinulosum) suggests that Michelilloa is an early representativeof the Cycadales.  相似文献   

20.
Biomphalaria tenagophila tenagophila, B. tenagophila guaibensisand B. occidentalis are indistinguishable on the basis of shellmorphology and the majority of organs of the genital system.Only B. t. tenagophila is susceptible to infection with Schistosomamansoni. The identification of this species is important forepidemiological studies of schistosomiasis. Snails from differentsites in Brazil, Argentine and Uruguay were studied using thePolymerase Chain Reaction (PCR) and Restriction Fragment LengthPolymorphism (RFLP) of the Ribosomal RNA Internal TranscribedSpacers (ITS) using seven enzymes. Profiles resulting from digestionwith AluI showed some invariant species-specific products allowingcorrect identification of B. t. tenagophila, B. occidentalisand B. t. guaibensis. Profiles obtained with other enzymes didnot permit species identification as extensive intraspecificpolymorphism or invariant RFLP profiles were observed. Restriction profiles obtainedwith all enzymes were used to calculate the percentage of bandsharing between all individual snails and these data were usedfor a cluster analysis. A closer relationship between B. occidentalisand B. t. guaibensis than B. t. tenagophila and the subspeciesB. t. guaibensis was observed. Based on previous morphologicaldata and these molecular data, we propose grouping B. t. tenagophila,B. occidentalis and B. t. guaibensis into a B. tenagophila complex. (Received 22 December 1997; accepted 26 May 1998)  相似文献   

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