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1.
本文报道了来自北美和亚洲10个四倍体披碱草属物种Elymus(StStHH)的核型.其核型属于1A或2A型,核型公式如下:24m+4sm(2sat)(加拿大披碱草E. canadensis);20m+8sm(4sat)(E. elymoides);20m+8sm(4sat)(E. glaucus);22m+6sm(4sat)(E.lanceolatus);22m+6sm(2sat)(E. mutabilis);22m+6sm(2sat)(老芒麦.E.sibiricus);24m+4sm(E.trachycaulus);22m+4sm+2st(2sat)(E.trachycaulus ssp.subsecundus);24m+4sm(4sat)(E.virginicus);20m+8sm(4sat)(E.wawawaiensis). 相似文献
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I. E. Kerkis 《Aquatic Ecology》1992,26(2-4):157-162
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The chromosome number and morphology of two species of the family Laelapidae have been determined: Hypoaspis aculeifer Canestrini, 1887 has 9() and 18() chromosomes and Cosmolaelaps miles Berlese, 1914 7() and 14(). Both karyotypes have monokinetic chromosomes and show obvious similarity. The longest chromosome of both species consists of a normal and a heterochromatic arm. The two laelapid mites prove to be arrhenotokous, as unfertilized females lay eggs from which only males arise. A theory has been postulated that within the Gamasida an evolutionary line towards arrhenotoky is present.Arguments supporting an independent evolution of sex determining system in the two acarine taxa Actinotrichida and Anactinotrichida are discussed. 相似文献
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Karyotypes and cellular DNA contents of three species of the family Cottidae viz.Icelus cataphractus, Gymnocanthus intermedius andAlcichthys alcicornis were analyzed. Structural modifications within the family were supposedly by Robertsonian translocations. The diploid chromosome numbers were determined to be 48 inAlcichthys alcicornis, 44 inGymnocanthus intermedius and 40 inIcelus cataphractus. The DNA contents ranged from 1.46 to 1.50pg/cell in the three species. The karyotype ofIcelus cataphractus is unique in having the smallest chromosome number (2n = 40) and 14 large-sized chromosomes. From the chromosome number and the existence of some large chromosome pairs, Robertsonian translocations seem to have occurred frequently inIcelus cataphractus andGymnocanthus intermedius. 相似文献
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The chromosomal picture was studied on early cleayage divisiona of 10 phytoseiid mites, using the aceto-orcein smear technique.
Eggs of 9 species have either a haploid (4) or a diploid (8) number of chromosomes:Amblyseius rubini Swirski & Amitai,A. swirskii Athias,A. hibisci Chant,A. ohilenensis (Dosse),A. largoensis (Muma),Typhlodromus athiasae Porath and SwirskiT. rhenanus (Oud.) sensu latiore,Phytoseiulus persimilis Athias, andI phiseius degeneraus (Berlese).Typhlodromus oceidentalis Nesbitt has 3 and 6 chromosomes.
In sections and smears of post embryonic stages belonging to mites representative of the four genera, a haploid number was
found in males, whereas in females somatic cells contained 2n and ovaries n as well as 2n. Thus it is shown that sex is determined
by the haplo-diploid (arrhenotokous) mechanism. Males differ from females in the structure of the interphase nuclei belonging
to the central nervous system.
Contribution from The Volcani Institute of Agricultural Research (NUIA.) Bet Dagan, Israel, 1968 Series, No. 1331-E. 相似文献
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F. Douglas Wilson 《Brittonia》1983,35(4):341-350
Karyotypes of 24 diploid (2n=12)Tragopogon species are similar with one long pair of chromosomes (A), two medium-length pairs (B and C), and three short pairs (D, E, and F). These species may be divided into three karyotypic groups: 1) seven species with a satellite on A and on D; 2) 14 species with a satellite on A only; and 3) three species with a satellite on D only. Most species within karyotype groups may be separated from each other either by distinctive features of certain chromosomes or by statistical differences in length of chromosome arms or long arm: short arm ratios of chromosome A. Three tetraploid (2n=24) species had two long pairs (A,A′), four medium-length pairs (B,B′;C,C′), and six short pairs (D,D′;E,E′;F,F′). Suggestions are made as to the putative diploid parents of these presumed allotetraploids. 相似文献
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Preparatory to the publication of the Flora of Ethiopia, the following new species and combinations are made: Loranthaceae: Plicosepalus robustus Wiens & Polh., P. ogadenensis M. Gilbert, P. acaciae (Zucc.) Wiens & Polh., P. meridianus (Danser) Wiens & Polh.; Oncocalyx angularis M. Gilbert, O. fischeri (Engl.) M. Gilbert, O. glabratus (Engl.) M. Gilbert, O. ugogensis (Engl.) Wiens & Polh., 0. schimperi (Hochst. ex A. Rich.) M. Gilbert, O. ghikae (Volkens & Schweinfurth) M. Gilbert, O. kelleri (Engl.) M. Gilbert; Erianthemum aethiopicum Balle ex Wiens & Polh.; Englerina woodfordioides (Schweinfurth) Balle ex M. Gilbert; Phragmanthera ahhallensis (Engl.) M. Gilbert, P. erythraea (Sprague) M. Gilbert, P. macrosolen (Steud. ex A. Rich.) M. Gilbert, P. regularis (Steud. ex Sprague) M. Gilbert, P. sarertaensis (Hutch. & Bruce) M. Gilbert, P. usuiensis (Oliver) M. Gilbert. Viscaceae: Viscum triflorum DC. ssp. nervosum (A. Rich.) M. Gilbert. 相似文献
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3种甘草属植物的核型研究 总被引:3,自引:0,他引:3
用光学显微镜观察了豆科(Leguminosae)甘草属(Glycyrrhiza)3种荒漠植物的染色体,研究结果表明,3种植物的体细胞染色体数目2n=16,核型公式分别为:刺果甘草(G.pallidiflara)k(2n)=2x=16=4M+8m+4sm,光果甘草(G.glabra)k(2n)=2x=16=10M+6m,胀果某草(G.inflata)k(2n)=2x=16=6M+6m+4sm。 相似文献
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GREGORY J. PRINGLE BRIAN G. MURRAY 《Botanical journal of the Linnean Society. Linnean Society of London》1993,111(3):331-342
The orcein and C-banded karyotypes of 11 species of Cyphomandra (Solanaceae) were described. All species were diploid with 2n = 2x = 24. The chromosomes were large, ranging from 4 to 10 u.m in length, and in each complement were largely metacentric or submetacentric with few subtelocentrics. There was a significant negative correlation between chromosome length and arm ratio within a complement as well as between taxa. In general, chromosomes of the larger complements were more symmetrical in terms of both relative chromosome length and arm ratio, implying that similar amounts of DNA had been added to or taken away from every chromosome are of each complement during evolutionary divergence. Two pairs of non-homologous chromosomes were seen to contain subterminal secondary constrictions in most species. The two Brazilian species studied differed from those of Andean origin in the location of one of these secondary constrictions, suggesting a major evolutionary divergence between these two groups of specieS. Non-homologous chromosomes were difficult to distinguish from one another without the aid of C-banding, due to a continuum in the distribution of chromosome lengths and arm ratios. Telomeric and interstitial bands were shown in all species but not all chromosomes in each complement were banded. There were no centromeric bandS. Nuclear DNA amount and the length, but not proportional length, of C-bands were correlated in each specieS. One species ( C. Luteoalba (Pers.) Child, section Cyphomandropsis ) was unique in its banding pattern, providing further evidence for the delimitatation of this species and perhaps section from other Cyphomandra taxa. 相似文献
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Karyotypes of four chironomid species were studied: Cryptochironomus obreptans Walker, Cryptochironomus sp., Chironomus plumosus Linnaeus, and Stictochironomus rosenscholdi Zetterstedt. All these species belong to the subfamily Chironominae. Each species is characterized by a specific karyotype structure. The first species in the list has 2n = 4, while the three other species have 2n = 8. 相似文献
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Chromosome studies, using the aceto-orcein smear technique, were made on embryonic tissue of eight Amblyseius Berlese species of the family Phytoseiidae. A haploid number of 4 chromosomes and a diploid of 8 were found. 相似文献
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对分布于我国的Lai木属Cornus L.(广义)4个主要类群的5种植物进行了细胞学研究。结果表明,这5种植物的染色体数目和核型分别为:灯台树C.controversa Hemsl.2n=20=2m 8sm 10st;红瑞木C.alba L.2n=22=8sm 12st 2t;毛Lai C.waltari Wanger.2n=22=8sm 14st(0-2SAT);山茱萸C.officinalis Seib.et Zucc.2n=18-8m 10sm(0-2SAT);四照花(变种)C.kousa var.chinensis Osborn 2n=22=2sm 6st(0-2SAT) 14t. 相似文献
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The chromosomes of 13 species of spider mites (Tetranychidae) are determined using the aceto-orcein squash technique in order to establish the haplo-diploid sex-determination. 12 species showed the existence of haploid and diploid eggs:Neotetranychus rubi (Trägårdh) with 7 and 14 chromosomes;Eurytetranychus buxi (Garman) with 5 and 10;Bryobia sarothamni (Geijskes),Eotetranychus tiliarium (Joh. Hermann) andE. carpini (Oudemans) with 4 and 8;Panonychus ulmi (Koch),Schizotetranychus schizopus (Zacher),Oligonychus ununguis (Jacobi).Tetranychus hydrangeae Pritch. & Baker, T.pacificus McGregor,T. urticae Koch andT. cinnabarinus (Boisduval) with 3 and 6 chromosomes.The progeny of virgin females in 7 different species consisted of eggs with the haploid complement. One species was shown to be thelytokous, viz.Tetranycopsis horridus (Canestrini & Franzago), having a diploid number of 4 chromosomes. Some eggs of an inbred line ofT. urticae showed a patchwork quilt of odd polyploidy in embryonic tissue. 相似文献
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The male meioformula of seven species of Cicindelini from the Iberian Peninsula and one species from Canada is 9+XXXY. In addition, female data of Cylindera paludosa corroborate previous reports of males. The Palearctic species show a generalized karyotype which presents specific modifications, but it is not possible to establish if it is also present in species of other faunas.Present data indicate that multiple sex chromosomes is an ancestral condition for the subfamily Cicindelinae. It is postulated that the meioformula of the tribe Cicindelini is 9 or 10 plus XXY and that trends in karyotypic evolution are partially related to the geographic distribution of lineages. Numerical deviations observed in the tribe can be explained by changes occurring independently in autosomes and heterosomes, so that autosome-heterosome fusions do not seem to be a generalized event. A number of criteria may be developed for determining the polarity of change of karyotypic characters, thus making cytotaxonomic studies a valuable tool for understanding the systematics of Cicindelini. 相似文献
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High salinity alters chloroplast morpho-physiology in a freshwater Kirchneriella species (Selenastraceae) from Ethiopian Lake Awasa 总被引:1,自引:0,他引:1
Ferroni L Baldisserotto C Pantaleoni L Billi P Fasulo MP Pancaldi S 《American journal of botany》2007,94(12):1972-1983
Plants differ in their ability to tolerate salt stress. In aquatic ecosystems, it is important to know the responses of microalgae to increased salinity levels, especially considering that global warming will increase salinity levels in some regions of the Earth, e.g., Ethiopia. A green microalga, Kirchneriella sp. (Selenastraceae, Chlorophyta), isolated from freshwater Lake Awasa in the Rift Valley, Ethiopia, was cultured in media amended with 0, 0.4, 1.9, 5.9, and 19.4 g NaCl·L(-1) adjusted with NaCl to five salinity levels adjusted with NaCl. Growth was monitored for 3 mo, then samples were collected for photosynthetic pigment determinations, microspectrofluorimetric analyses, and micro- and submicroscopic examinations. The best growth was found at 1.9 g NaCl·L(-1). In the chloroplast, excess NaCl affected the coupling of light harvesting complex II and photosystem II (LHCII-PSII), but changes in thylakoid architecture and in the PSII assembly state allowed sufficient integrity of the photosynthetic membrane. The mucilaginous capsule around the cell probably provided partial protection against NaCl excess. On the whole, the microalga is able to acclimate to a range of NaCl concentrations, and this plasticity indicates that Kirchneriella sp. may survive future changes in water quality. 相似文献