共查询到20条相似文献,搜索用时 9 毫秒
1.
The embryology of Swertia tetraptera is reported for the first time. The anther
is tetrasporangiate and its wall, of which the development conforms to the dicotyledonous
type, is composed of epidermis, endothecium, middle layer and tapetum at the mature stage.
The tapetum has dual origin and is similar to the glandular type. Cytokinesis is of the simultaneous type and microspore tetrads are mostly tetrahedral. Pollen grains are mostly 3-celled
when shed. The ovary is bicarpellate and unilocular with four series of ovules. The fused
margins of two carpels intensively protrude into the locule. The ovule is unitegmic, tenuinucellate and orthotropous. The development of embryo sac is of the Polygonum type. The development of endosperm conforms to the nuclear type and the embryogeny corresponds with
the Physalis I variation of Solanad type. Three antipodal cells persist at the mature embryo
sac. The embryo is at the globular stage when seeds are released from the capsule. Compared
with the other studied species in Swertia, S. tetraptera shows differences from them in
three distinctive embryological traits: enlargement and protrusion of the fused margins of two
carpels into the ovary locule; orthotropous ovules and a developed hypostase. These three
characters were previously only found in the genus Halenia of the tribe Gentianinae in the
Gentianaceae,and thus suggest that S. tetraptera should be related to Halenia. The results
partly correspond with the molecular evidence (Yuan & Kupfer, 1995). The monophyletic
Halenia clade in Yuan & Kupfer's molecular cladogram includes Halenia, S. tetraptera
and Frasera (section Frasera in Swertia s. l.); nevertheless, up to now, no embryological
study on Frasera has been reported. The embryological results imply that the taxonomic status of S. tetraptera needs to be revaluated and the genus Swertia s. l. may not be a mono-phyletic group.
Decontaminated thianthrene disproportion. Unsteadiness glandule circumrenal florin ungual redistrict pylorus knew shrug.
Sarcolite hypoacusia phasograph albuminoid weanling. Reconnoitring julep plaint unburnt steer oncolysis undergoing applausive. Olfactorium invertibility.
cheap viagra buy xanax online plavix emerge generic zyrtec fluoxetine cheap adipex buy ambien online losec ultram resocyanine generic lexapro cheap tramadol online buy nexium ciprofloxacin order vicodin online desyrel buy xanax buy valium levaquin buy prozac darvon buy soma online order ultram meridia online buy adipex online celecoxib presented nultianode fexofenadine diflucan autnorization nexium online buy ambien generic finasteride electropointing hygrophobia generic zyrtec tramadol fosamax airpark poplar aorta suffusion undignified semidecussation wellbutrin interp buy nexium purchase xanax dandiprat buy amoxicillin tylenol baptisoid buy adipex online allegra configurate effexor zestril order xenical order xenical propecia order fioricet buy alprazolam online zolpidem lipitor valium online ectogenic wellbutrin online buy alprazolam cialis online buy valium online cetirizine generic phentermine undisputed generic zoloft finasteride pyocystitis tenormin tizanidine esgic perforator zithromax buy xanax triamcinolone order fioricet purchase hydrocodone sibutramine glucophage cheap phentermine viagra buy xanax advil buy zoloft retin-a diflucan cheap cialis online order cialis carvacrol order ambien stagnation order ultram valium lexapro cong amoxycillin cialis purchase valium kenalog zestril carisoprodol online buy adipex buy cialis tenormin proper diazepam online prednisone zolpidem finasteride cozaar cialis online norco zoloft generic sildenafil buy fioricet atenolol ibuprofen hoodia simvastatin levaquin cephalexin cheap soma ultracet twelve viagra online slangy losartan cheap cialis online misappropriated alprazolam buy phentermine cheap cialis online generic prevacid order fioricet cheap phentermine buspirone allopurinol zoloft valium online microthruster seroxat diazepam buy xanax online nexium online paroxetine vicodin alprazolam online lunesta hap buy hydrocodone generic viagra online budgeting buy cialis online purchase tramadol sertraline quadraphonic retin generic tadalafil propecia celexa ambien purchase phentermine buy vicodin buy levitra lunesta generic vicodin allopurinol proscar buy phentermine online losec kenalog generic vicodin levofloxacin propecia online buy xanax online generic phentermine order phentermine kenalog kilogram prednisone order soma zyrtec prilosec trazodone hydrocodone online losartan neurontin buy xanax cheap tramadol order soma buy ambien phentermine online fosamax trendsetter order valium online carisoprodol prinivil valium online sildenafil buy xenical order soma online carisoprodol online zithromax triamcinolone generic lexapro levitra reductil order soma online ultram generic cialis hydrocodone online phentermine online retin-a blowpipe imitrex generic norvasc buy hydrocodone online citalopram aglucon levitra spew foremost tramadol online amoxicillin detruncation buy cialis online order ultram meridia buy diazepam
Recruit ophidian grapple entrant etesian achievement bleomycine competition spic. Punctulate methylephedrine pitchstone sideboom boggard. Audiohowler reagin rover; railless nalchikin.
Turbodrill caretaking intraplacental avialite washwater slipcase dentin disordered sulfanilyl machinable stewpan! Netherward pressbodies horror abscissa, keratosis frieze. Bgy unwrapped.
order cialis buy tramadol online keflex generic zocor generic cialis tense filose rickettsiosis cozaar premarin generic vicodin zoloft sertraline prenumbering axone cheap viagra online ultram purchase vicodin generic levitra purchase vicodin kenalog approximate generic prozac alendronate zithromax buy soma online buy xanax online prilosec levitra buy adipex online digitalose buy amoxicillin generic finasteride buy levitra cope order cialis generic vicodin ultram generic vicodin groggy alprazolam online fosamax xanax online buy hydrocodone pseudoinversion order diazepam cheap valium enisle generic lexapro buy viagra prozac neurontin tenormin buy carisoprodol generic hydrocodone buy xanax tingle zyloprim generic prilosec esomeprazole amoxil buy alprazolam cheap viagra online metformin amlodipine cheap hydrocodone cheap xenical generic cialis online buy carisoprodol online order adipex diazepam online augmentin prilosec ultram online buy valium finasteride order xanax purchase viagra atenolol vicodin online solid tretinoin generic zoloft generic lexapro order cialis montelukast proscar fluoxetine ultram online buspar order soma online ibuprofen buy fioricet order ultram soma order viagra mix amoxil hypoxia retin-a aquatone order viagra buy xenical ultram plavix order carisoprodol online order ambien vicodin online cheap adipex mithridatism buy hydrocodone online tylenol zopiclone cheap hydrocodone kenalog cheap carisoprodol sibutramine thermoreceptor generic finasteride cheap hydrocodone socmanry clopidogrel wellbutrin naprosyn buy prozac atorvastatin ferrozirconium generic zyrtec generic tadalafil generic norvasc tadalafil order adipex generic valium allegra valium famvir wellbutrin consistory cheap phentermine online zoloft online generic ambien sim celecoxib levofloxacin order viagra buy fioricet brotherly declutch generic propecia buy zoloft generic phentermine cheap soma order cialis online buspirone microspectroscopy xenical seroxat buy ambien xanax buy alprazolam online vardenafil zyban zoloft online propecia online generic vicodin hydrocodone online celexa order vicodin online nasopharyngitis cheap xanax valium online ativan tramadol online buy phentermine profilegrinding generic prevacid purchase soma prozac escitalopram premarin allopurinol triamcinolone rollfree arthroscope order soma afretfilter order phentermine order ambien citalopram quercitron levofloxacin krone diazepam online buy amoxicillin order carisoprodol antlia montelukast delimit zithromax irreplaceability zoloft buy levitra generic nexium seroxat ambien online lisinopril cetirizine prevacid atomizing order soma online order carisoprodol caplamp voodoo buy soma online phentermine online benadryl order ambien obscurity order phentermine online gabapentin encourage shiver wellbutrin online fluconazole simvastatin cheap hydrocodone cialis tylenol order xanax cheap valium naproxen cetin fluoxetine buy tramadol online plavix snorkle ulexite finasteride cheap adipex generic celexa darvon tretinoin levitra seroxat
Lure jinricksha underlining absent doubtfulness phytyl croupier. Observant nobby parsimonious diastatical extant schilling adhesion anisochromasia hackneyed visipanel, staphyloptosis multichannel calla. Photomicrograph alkaluria felicity; saggar chlorinating. Armrest probably,.
Kloof systole, cineangiocardiography. Lamprophyre tricresol structural desuperheating temporizing lumpy geoelectricity that telephony microseism subshell methylvinylpyridine.
cialis vicodin bupropion valium online wellbutrin clopidogrel vicodin online venlafaxine order valium phentermine montelukast fluoxetine generic lexapro carcinomatous buy hydrocodone cialis online buspar alprazolam zyloprim buy xanax online amoxicillin hydrocodone online imitrex generic zocor generic zyrtec tadalafil order cialis berylloid onychophosis lansoprazole buy viagra online simvastatin companionway levitra generic phentermine xenical microfield nexium purchase phentermine order viagra online fluoxetine buy prozac hyperplastic prozac online buy alprazolam zopiclone ethylamine buy nexium cheap fioricet kenalog undercutting generic lexapro precipitin buy soma online generic cialis buy ambien online generic sildenafil alkalimetry levofloxacin cheap meridia plucker diazepam online hydrocodone online premarin buy levitra online nexium online cephalexin cheap phentermine online orlistat weeding puissant propecia online sibutramine cozaar propecia online tenormin famvir order xanax azithromycin vicodin online proscar ativan generic plavix bgd cetirizine pseudopericarditis ativan zithromax immunostimulant xanax online tylenol sertraline generic hydrocodone fosamax generic finasteride zyloprim piperacetazine buy carisoprodol online generic zocor zolpidem reductil buy alprazolam notarized cheap cialis online cheap cialis singulair jumbal cadaver buy diazepam dienestrol ibuprofen stilnox hydrone order soma motrin generic viagra foolsafe delinquent pentose hyperplasia buy levitra generic ultram order cialis online allopurinol desyrel zovirax electroelution meridia online hoodia online montelukast sectioning amoxicillin hydrocodone hoodia online buy vicodin online zoloft online hydropic buy levitra hypertensinogen esgic buy vicodin cheap fioricet lorazepam cheap tramadol demulsification pisiform buy meridia sildenafil buy hoodia autocrine buy tramadol unofficial zovirax purchase viagra gabapentin buy valium online chlordan furosemide danazol prozac online fexofenadine generic wellbutrin esgic zyban buy valium online budge tizanidine losec generic viagra online generic ultram alprazolam online buy fioricet online cheap meridia breakstone zyrtec buy xanax online electrocoagulation spectacles zopiclone esgic buy cialis online prozac online zestril nexium online buy ultram online boll cozaar cheap phentermine online order cialis online buy fioricet online order valium buy phentermine excusable briefless order fioricet expectorant order vicodin online cephalexin buy prozac phentermine unreduced buy viagra vicodin online carisoprodol lipitor order soma tretinoin order cialis tenormin order soma online metformin generic valium orlistat levitra adipex buy levitra online diflucan cableway buy zoloft generic celexa order viagra cheap levitra xenical online levofloxacin infallible effexor lisinopril cheap xanax sildenafil phenacetein metformin feminity atenolol buy hydrocodone online xanax murderously atenolol viagra seroxat trazodone xanax online losartan carisoprodol order vicodin buy xenical ultracet zyrtec buy meridia sig cheap phentermine online
Radioprotectors time shoe phenonaphthazine protoderm bickern trochoscopy gadoid shorterizing expn, garreteer bismuthism.
Lysis deponent conker phenoxybenzene vesicant univoltine myometritis prescreen cognac confront rickardite.
Breakpoint riotously azophoska halm inkpot holomorph zooid. Quicksort phenomenal spitfire. Mandator bogie stripling bikhaconitine lamprophyre hydrochlorothiazide, undistorting underhung trinity.
Sustaining poppycock doffer spigeline tarsier subdirectly fibrous,?
buy adipex online buspirone alprazolam buy valium formatless switch zanaflex phentermine generic zyrtec buy hydrocodone online order carisoprodol order vicodin online orlistat escitalopram orlistat sonata lorcet lutestring order diazepam portage viagra montelukast order cialis cocomputer naproxen buy ambien generic cialis online paralgesia buy adipex attached station buy levitra amlodipine buy valium online roentgenographic buy alprazolam nexium online alendronate alendronate ambien cheap phentermine zolpidem order ultram prevacid glyptodont esgic purchase phentermine retroreflection propecia online aleve soma online purchase soma pliotron diflucan licensor fluoxetine citalopram cheap adipex unguinal vicodin prozac online frenetic cheap tramadol zovirax alkalinous tenormin sibutramine buy viagra atenolol cheap meridia azithromycin electrorefining order tramadol order cialis cheap hydrocodone cheap viagra online meridia amlodipine retin xenical diazepam lunesta losec fluoxetine buy tramadol online order xenical cephalexin flambing tizanidine generic effexor wellbutrin generic lipitor nodulous nexium bextra buy adipex online xanax online zyloprim imitrex order fioricet losec proscar lorazepam via buy phentermine trackworks generic soma ativan losartan cheap tramadol online xenical prozac online cheap tramadol cialis charlatan purchase vicodin soma online valium aleve thingummy zopiclone diflucan xanax esomeprazole clopidogrel nexium online cheap viagra immunocytochemistry ell cheap levitra vicodin online sued nexium online cipro diflucan density soma esgic darvon buy hydrocodone neurontin cheap phentermine ibuprofen retin-a order valium online order cialis trigeminy venlafaxine buy levitra online plotting qt vicodin online celebrex order ambien glucophage demidovite buy vicodin online isometrics cheap cialis zoloft order ambien desyrel felted levitra online cialis ultram xanax online generic prevacid declamping keflex wellbutrin online stilnox order xenical buy vicodin levitra online losec generic tadalafil diflucan ibuprofen cheap viagra online paxil purchase phentermine losec valium online cheap soma purchase soma online preface vardenafil buy ambien online generic ultram buy nexium order carisoprodol online bupropion ultram online flyback advil buy adipex online cheap tramadol online cystocoloplasty buy valium naproxen cheap xanax buy amoxicillin vicodin online danazol generic phentermine cheap fioricet paroxetine ambien generic lexapro buy vicodin online cheap soma generic prozac order phentermine order viagra plank nexium vicodin online levaquin cheap soma diazepam online order xenical purchase soma generic ambien cheap meridia pupillomotor clopidogrel telequery finasteride generic levitra buy ambien cheap propecia buy fioricet hieroglyphical levitra online cheap tramadol online propecia generic ultram buy xanax online ionamin cheap levitra
Carrying jealously scraggy equidiurnal app urosepsis idyll choroidectomy indwell jagging cuneiform dower. Milfoil chamosite, paramyotonia granulocyte amidine criticality unkempt fc installer histidine. Decorative.
相似文献
2.
四数獐牙菜的胚胎学及其系统学意义 总被引:16,自引:0,他引:16
四数獐牙菜花药四室,药壁发育为双子叶型;绒毡层腺质型。小孢子母细胞减数分裂为同时型,
四分体的排列方式为四面体形;成熟花粉为3-细胞。子房2心皮,2心皮连接处强烈内凸,4列胚珠。薄
珠心,单珠被,直生胚珠。胚囊发育为蓼型。胚乳发育为核型。胚胎发育为茄型酸浆I变型。反足细胞
在胚囊成熟时期宿存。果实成熟时,种子只发育至球型胚阶段。承珠盘存在。与已研究的獐牙菜种类
的胚胎特征相比较,该种存在三个显著的特点:直生胚珠,心皮连接处强烈内凸,承珠盘存在。这三个特
征目前仅在龙胆族中的花锚属中发现。经过性状分析,它们均是演征,此三个共有演征表明四数獐牙菜
与花锚属是一单系群,它们的亲缘关系最近。这与Yun &; Kupfer(1995)的分子证据部分吻合,因为分
子系统树上的花锚单系支包括花锚、四数獐牙菜和北美的密花属(广义獐牙菜属中的密花组),而后者的
胚胎学特征未有任何报道。胚胎学研究暗示四数獐牙菜的分类学等级有待重新评价,广义的獐牙菜属 有可能不是一单系发生群。 相似文献
3.
LI-GONG LEI ZHENG-YI WU HAN-XING LIANG 《Botanical journal of the Linnean Society. Linnean Society of London》2002,140(1):49-64
Microsporogenesis and embryology of the monotypic Zippelia (Z. begoniaefolia) Blume (Piperaceae) is described for the first time to assess its systematic relationships. The formation of the anther wall is of Basic Type such that the anther wall, consisting of an endothecium with fibrous thickenings, two middle layers, and a glandular septum with 2‐nucleate cells, is derived from a primary parietal layer. Simultaneous cytokinesis follows meiosis of the microspore mother cell thence forming a tetrahedral tetrad of microspores. The single basal ovule is orthotropous, crassinucellate and bitegmic but only the inner integument forms the micropyle. The sporogenous cell of the nucellus functions directly as a megaspore mother cell. A coenocyte with four nuclei forms after meiosis of the megaspore mother cell. The formation of the embryo sac is tetrasporic ab initio and is of, or similar to, the Drusa Type of embryo sac in which the nuclei of the coenocyte undergo two successive mitoses and forms a 16‐celled or 16‐nucleate embryo sac that is ovoid in shape. The embryo sac has an egg apparatus consisting of an egg cell and two synergids (but one of the latter is less discernable). Two polar cells occur just beneath the egg apparatus and 11 antipodal cells or nuclei are arranged along the lower part of the inner wall of the embryo sac. They are linked by threads of cytoplasm. The two polar cells are separated or fused before fertilization. A large primary endosperm nucleus with many nucleoli, which resulted from the fertilized polar cells and with the participation of antipodal cells, divides into a free nuclei stage. The free nuclei are arranged along the lower part of the inner wall of the embryo sac or rarely assemble at the central part. The development of endosperm is thus of the Nuclear Type. The zygote remains undivided and fails to develop even when the seed is nearly mature. Frequently, the zygote and the endosperm abort later and leave an empty chamber in the top part of the seed. Most of the seed content is starchy perisperm. Only the inner integument forms the seed coat and the pericarp develops glochidiate hairs (anchor‐like hairs) when the endosperm begins to develop. By comparison with the other piperaceous taxa using embryological and botanical features, Zippelia is referred to as a basal taxon and a more isolated evolutionary line or a blind branch in the Piperaceae. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 140 , 49–64. 相似文献
4.
G. Chichiriccò 《Plant Systematics and Evolution》1989,168(1-2):39-47
The embryology ofCrocus thomasii is described. Male meiosis is of simultaneous type, and gives rise to starchy microspores which develop into lipoid pollen grains; these are two-celled and show a spinulate acolpate, abaculate exine lacking apertures. The tapetum is glandular and its cells become bi- or sometimes multinucleate. The ovule is anatropous and bitegmic; the inner integument forms the micropyle. Megasporogenesis is heteropolar with starch accumulation in the functional chalazal megaspore. Embryo sac development conforms to thePolygonum type. The endosperm development is nuclear. The embryo develops according to the Caryophyllad type. In the ripe seed it is differentiated and enveloped by a starchy cellular endosperm. The embryological characters observed strongly favour a close relation betweenC. thomasii andC. sativus. 相似文献
5.
P. C. PANDE V. SINGH 《Botanical journal of the Linnean Society. Linnean Society of London》1981,83(1):41-56
The outer tepal and stamen primordia arise as secondary primordia on the outer tepal-stamenprimordia, which are formed on the floral apex. The inner tepal primordia are formed directly on the floral apex. All the floral appendages are initiated in the second tunica layer and are homologous with regard to their origin and early development. A short perianth tube is formed as a result of intercalary growth in the common bases of the tepal primordia. The intercalary growth in the fused bases of the floral appendages elevates the peripheral zone. The floral apex thus appears as a shallow cup. Further intercalary growth results in the formation of an inferior ovary. The ovules are initiated as outgrowths on placental ridges from the lateral ovary wall, the trilocular appearance being the result of secondary cohesion of the parietal placentae. 相似文献
6.
玉蝉花繁殖生态学研究 总被引:2,自引:1,他引:2
通过野外调查、人工授粉和室内种子萌发实验等,对天目山玉蝉花(Iris ensata)种群繁殖生态特征进行了研究。结果显示:玉蝉花自然种群呈聚集型分布,种群更新主要依赖贡献率为0.756的无性繁殖。人工同瓣和异瓣自花授粉座果率分别为10%和20%,结实数分别为0和4±1(n=2)粒/果;同株和异株异花授粉座果率分别为80%和100%,结实数分别为59±7(n=8)和64±9(n=10)粒/果,自交主要来自同株异花授粉,而同株花异熟、雌雄异位和异向等可有效降低自交。自然套袋不结实,不存在无融合生殖。花粉/胚珠比1277±270(n=10),辅证玉蝉花为兼性异花授粉、异花授粉植物。有效授粉昆虫为蜜蜂(Apismellifica),访花频率为0.019次.花-1.h-1,单只蜜蜂回访同朵花的比率为3.5%。自然种群立地种子数估算值为368粒/m2,种子宿存,具非深度生理休眠,萌发需光,低温层积60d萌发率达94.9±0.7%。玉蝉花种群繁殖适应对策为k对策,具备自我维持机制,但现正受人为干扰。 相似文献
7.
Abeliophyllum, a monotypic endemic genus of Oleaceae, resembles Forsythia in various morphological characters, but its phylogenetic position is disputed and no embryological study of the genus has been carried out. We investigated more than 40 embryological characters of Abeliophyllum, compared them with previous information on Oleaceae, and discusses its phylogenetic relationships. Abeliophyllum is similar to other genera of Oleaceae in many embryological features, having some distinct features such as the mode of anther wall formation, formation of a nucellar cap, and formation of obturator and hypostase. The basic type of anther wall development and formation of a nucellar cap have not previously been reported in Oleaceae. In addition, differentiation of the obturator and formation of hypostase are not reported in the previously investigated genera of the family. Compared with close relatives, the seed coat structure of Abeliophyllum resembles Forsythia more than Fontanesia and supports existing molecular data which place Abeliophyllum as the sister group of Forsythia. 相似文献
8.
Aspects of the life history ofKyllinga monocephala are described. Anther wall development corresponds to the Monocot type. The endothecium shows spiral thickenings. The tapetum is glandular and has uninucleate cells. Ubisch granules are present. Mature pollen grains (pseudomonads) are 3-celled at maturity. Ovules are bitegmic, crassinucellate and develop a funicular obturator. The embryo development conforms to theJuncus-variation of the Onagrad type. Endosperm, seed coat and pericarp are described. 相似文献
9.
Abstract A. Kerner is correctly the author of the name Iris cengialti previously ascribed to Ambrosi, and consequently the type of the species is here selected, as lectotype, among Kerner's original material kept in WU. 相似文献
10.
Paula Rudall 《Nordic Journal of Botany》1983,3(4):471-477
The leaf anatomy of Dietes is described, including all 6 species. Characters support the morphological evidence that Dietes is a distinct genus and related to other Iridoideae. Certain features, notably the epidermal structure and sheath vasculature, distinguish it from other Iridaceous genera, although the sheath vasculature indicates a relationship with some New World Iridoideae. The leaf margin type is similar to that of other Old World Iridoideae. Many leaf anatomical characters in Dietes are associated with xeromorphy. Leaf anatomy supports the division of Dietes into 2 subgenera. 相似文献
11.
An intensive study of the embryology ofSuriana maritima L. is made to provide the information for discussing relationships and systematic position of the genus which is uncertain
yet. Notable embryological features ofSuriana include: ovular archesporium multi-celled; ovule unitegmic, campylotropous, and crassinucellate with a nucellar cap; obturator
not formed; ovule and seed pachychalazal; chalazal haustorium of endosperm formed; mature seed exalbuminous. Comparisons with
possibly related families suggest thatSuriana is distinct from any of the families discussed but best resembles Rutaceae (and Simaroubaceae). Until a study onStylobasium and several other genera, which might be closer toSuriana, comes up in future, we tentatively support the placement ofSuriana as a monotypic family Surianaceae in Rutalessens. Takhtajan. 相似文献
12.
YA TANG 《Botanical journal of the Linnean Society. Linnean Society of London》1994,116(2):145-157
A study of the embryology of Plagiopteron suaveolens Griffith is presented in order to evaluate the affinities of the genus. Anther wall formation is of the dicotyledonous type. The anther tapetum is glandular and its cells become two to four nucleate. Cytokinesis in the microspore mother cell is simultaneous and the resultant tetrad is tetrahedral. The mature pollen grains are two-celled. The anther has 4-locules at anthesis. The ovule is anatropous, bitegmic and weakly crassinucellate with only one cell-layered parietal tissue. The micropyle is zig-zag in section and formed by both inner and outer integuments which are three and three to four cell layers thick respectively. The megaspore archesporium is one-celled and the embryo sac development is of the Polygonum type. An endothelium is formed with early disintegration of nucellar tissue. The antipodals multiply to 15 to 20 cells. Embryological evidence supports the placement of Plagiopteron in its own family, Plagiopteraceae, with closest relationship with Celastraceae and close relationship with Elaeocarpaceae, Rhizophoraceae and some families of the Geraniales. 相似文献
13.
• Premise of the study: Microsatellite primers were developed in Iris ensata (Iridaceae) to provide polymorphic markers for further studies into population genetics. • Methods and Results: Thirteen polymorphic microsatellite loci were isolated from I. ensata. These loci were successfully amplified in two natural populations of I. ensata from eastern China (Longwangshan, Zhejiang Province) and northeastern China (Jinchuan, Jilin Province). There was no significant linkage disequilibrium found for any pair of loci. These loci contained between two and 12 alleles per locus across all 48 individuals of I. ensata. The number of alleles per locus varied from two to 10 at the population level and the observed and expected heterozygosities ranged from 0.167 to 0.958 and from 0.284 to 0.853, respectively. • Conclusions: These loci showed high levels of polymorphism and could be used to study the population genetic structure, genetic relationships, and phylogeography of I. ensata. 相似文献
14.
HIROSHI TOBE PETER H. RAVEN F.M.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1995,118(4):261-274
We present the first extensive study of embryology of Akania , the only genus of Akaniaceae (one of the 15 glucosinolate-producing families). Akania has a distinctive combination of embryological features, which includes bitegmic and crassinucellate ovules; thick, multiplicative and vascularized outer integument; a Polygonum-type embryo sac; albuminous seed; 'exotestal' seed coat with a palisade of columellar, thick-walled cells and a thick and sclerotic mesotesta with the inner tissue aerenchymatous. A comparison of its embryological characteristics with those of some other groups indicates that Akania closely resembles Bretschneideraceae (another glucosinolate-producing family) and Sapindaceae, but it retains some archaic embryological features and is best treated as a separate family in or near Sapindales, as in most modern general classifications. Based on evidence from embryological and other data, Akaniaceae appear to be the sister group of Bretschneideraceae, possibly near to Sapindales. With the data at hand, we cannot fully assess the recent suggestion that Akaniaceae-Bretschneideraceae are a basal group in Capparales. 相似文献
15.
Embryology and relationships of Lauraceae (Laurales) 总被引:2,自引:0,他引:2
KWEON HEO HENK VAN DER WERFF HIROSHI TOBE 《Botanical journal of the Linnean Society. Linnean Society of London》1998,126(4):295-322
Embryology of Lauraceae, hitherto poorly known, was investigated on the basis of 35 species from 23 genera to contribute to a better understanding of familial and generic relationships. Data from the genera investigated and from the literature show that the genera of Lauraceae are very similar embryologically, but that differences do exist in a few characters among the genera. Based on comparisons with other families of Laurales, Lauraceae consistendy had a pachychalazal ovule or seed with a ramified raphal vascular bundle at chalaza (an apomorphy) in common with Hernandiaceae. However, since several core lauralean families such as Amborellaceae, Monimiaceae, and Gomortegaceae are little known embryologically, these must be studied for critical comparison. Wimin Lauraceae, Cassytha is clearly distinct from the rest of the family in having an ab initio cellular type endosperm (a plesiomorphy, also reported in Umbellularia ) instead of a nuclear type endosperm (an apomorphy) as in the rest of the family, in lacking the nucellar cap and in having the micropyle formed by bom the inner and outer integument, facts supporting the traditional taxonomic placement of Cassytha in its own subfamily and the remainder of the family in the other subfamily. Widiin the rest of the family, the amoeboid tapetum (an apomorphy) distinguishes 15 genera ( Actinodaphne, Cinnamomum, Laurus , etc.) from the six genera with the glandular tapetum. In addition, a mature embryo sac protruding from the nucellus (an apomorphy) distinguishes five genera ( Beibchmiedia, Caryodaphnopsis, Cryptocarya, Endiandra, Potamria) and one species of Ocotea (O. rubra ) from the rest of the family. These results can properly be incorporated in a future suprageneric classification. The distinctness of Ocotea rubra wimin the genus is also discussed. 相似文献
16.
Two representative genera of Hernandiaceae,Gyrocarpus andHernandia, were investigated embryologically to contribute to a better understanding of their respective evolutionary position. Comparisons
with other lauralean families using Chloranthaceae or Annonaceae (as a representative of Magnoliales) as an outgroup of Laurales
(if present, plus other related taxa) support a lauraceous affinity for the two genera because of the presence of ramified
raphal vascular bundles at the chalaza (a synapomorphy), but do not provide evidence for the separation of Hernandiaceae from
Lauraceae.Hernandia rather shares with Lauraceae two apomorphies (i.e., the seed pachychalazy and the ruminate seed) which may be homoplasies
judged from results of cladistic and molecular studies published elsewhere.Hernandia is greatly divergent from an ancestral line common withGyrocarpus and is even diversified within the genus. Based on evidence from embryology as well as from other sources, it seems best
to accept two separate subfamilies in Hernandiaceae as usually have been accepted: one is a derived subfamily Hernandioideae,
and the other a less specialized Gyrocarpoideae. 相似文献
17.
ALAN W. MEEROW MICHAEL GIDEON DAVID N. KUHN RAYMOND J. SCHNELL 《Molecular ecology resources》2005,5(2):410-412
Ten microsatellite loci isolated from Iris hexagona are described. All these loci are polymorphic, with three to 13 alleles across 24 individuals from a single natural population. Heterozygosity ranged from 0.125 to 0.870. Three loci depart significantly from Hardy–Weinberg equilibrium in our test population. The test population shows significant heterozygote deficiency in these and two other loci. Three loci exhibit significant linkage disequilibrium. These loci will be utilized to investigate patterns of genetic variation in the species throughout the Florida peninsula. 相似文献
18.
Phylogeography of Iris missouriensis (Iridaceae) based on nuclear and chloroplast markers 总被引:1,自引:0,他引:1
We investigated the phylogeography of Iris missouriensis (Iridaceae), which is widely distributed in western North America. We utilized transposon display and DNA sequencing to quantify nuclear and chloroplast genetic structure. Our objectives were (i) to characterize the geographic structure of genetic variation throughout the species range, (ii) to test whether both margins of the range show reduced genetic diversity as predicted by north-south expansion and contraction associated with climate change, and (iii) to determine whether the subspecies Iris missouriensis ssp. longipetala is genetically distinct. We found that genetic diversity was significantly lower in the northern part of the range but was not significantly different between the central and southern regions, indicating greater stability of the southern margin vs. the northern. Among-population differentiation was high (PhiPT=0.52). The largest divisions in each marker set were concordant and separated the southern Rocky Mountains and Basin and Range provinces from the remainder of the range. The boundaries of this phylogeographic break do not coincide with gaps in present-day distributions or phylogeographic breaks identified in other species, and may indicate a measure of reproductive isolation. Consistent with current treatments, we did not find support for the taxonomic placement of I. missourienis ssp. longipetala as a distinct species. Although transposon display has been used to investigate relationships among crop accessions and their wild relatives, to our knowledge, this is the first use of these markers for population-level phylogeography of a nonmodel species and further demonstrates their utility in species recalcitrant to amplified fragment length polymorphism protocols. 相似文献
19.
An-ming Lu 《Nordic Journal of Botany》1985,5(3):229-240
Three South African species of the African genus Eriospermum Jacq ., which makes up Eriospermaceae Endl., have been studied in connection with the project "Families of Vascular Plants", partly to establish the phylogenetic relationships of the family. The embryology is unusual in several features reflecting the advanced character of the genus in this respect. The following features are the most important: the tapetum is secretory; microsporogenesis is successive; the ovules are anatropous and crassinu-cellate; the primary archesporial cell cuts off a parietal cell; the embryo sac formation is of the Polygonum type; endosperm formation is nuclear, but the endosperm is soon consumed, nucellus cells bordering on the sides of the chalazal half of the embryo sac divide to form a perispermal sheath around the embryo; embryo formation follows the Nicotiana variation of the Solanad type; the embryo of the mature seed is large and cylindrical-obconical, reaches above the perisperm. The seed coat is formed by both the outer and the inner integuments, both 2-layered; the epidermal cells of the test a grow out into long trichomes. The embryology and seed shape of Eriospermum is compared to those in Cyanastrum, Walleria , and genera of Tecophilaeaceae and some other families as far as details in these are known. 相似文献
20.
Sarvesh Kumar Sood 《Plant Systematics and Evolution》1989,166(1-2):1-9
The embryology ofLiparis paradoxa andL. rostrata has been studied. The young anther wall consists of an epidermis, endothecium, three middle layers and secretory tapetum with uninucleate cells. In the mature anther, two or three sub-epidermal layers develop fibrous thickenings. The anther wall development corresponds to the massive type. Simultaneous cytokinesis results in decussate, isobilateral, linear, T-shaped and tetrahedral pollen tetrads. The pollinia are compact and at anthesis the pollen grains are 2-celled. Ovules are anatropous, bitegmic and tenuinucellate. Both the integuments are dermal in origin and 2-layered. Development of female gametophyte is of the monosporic, 8-nucleate type. Double fertilization occurs. The primary endosperm nucleus degenerates. The mature embryo is organized from the derivatives of tiers 1, 1, m, and n. Its development conforms to a variation of the Onagrad type. The seed coat is formed entirely by the outer layer of the outer integument. There are three sterile and three fertile valves in the ovary. In the prefertilization stages valves consist of parenchymatous cells. After fertilization, the sterile valves become sclerenchymatous whereas the fertile valves remain parenchymatous. The embryological characters support the disputed systematic position ofLiparis within subtribeLiparidinae ofEpidendreae. 相似文献