Taxonomic significance of leaf surface morphology in Aloe section Pictae (Xanthorrhoeaceae)

Leaf surface morphology was analysed in 32 species representing the maculate species complex (the poorly resolved section Pictae) in the genus Aloe (Xanthorrhoeaceae). Few comparative morphological data are available for the complex. Leaf surface and stomatal characters observed by scanning electron microscopy show taxonomically significant interspecific variation. Most species are characterized by irregularly outlined, four‐ to six‐sided epidermal cells, the periclinal walls of which are flat and embellished with micropapillae and the anticlinal walls of which are indicated by channels on the leaf surface. The outer stomatal pore is typically sunken or plane and surrounded by four lobes on the leaf surface that may overarch the epistomatal chamber. The guard cells have distinct outer and inner stomatal ledges. Two geographical groups, comprising southern and east African species, are distinguishable by their leaf surface morphology. These characters are diagnostic in A. ellenbeckii, A. prinslooi and A. suffulta and support changes in the delimitation of A. greatheadii, A. macrocarpa and A. swynnertonii. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 418–428.     

两种芋属(天南星科)植物的核型研究

报道了芋属两种植物的核型,结果如下:异色芋2n=2X=28=18m+10sm,属于“2B”类型;花叶芋2n=2X=28=20m(8sat)+8sm(2sat),属于“2A”类型;花叶芋的核型及两个种之间的核型比较系首次报道。     

八个四倍体鹅观草属物种的核型研究

对8个鹅观草属物种的核型进行了研究。核型公式如下:纤穗鹅观草2n=4x=28=20m+8sm(2sat);紫穗鹅观草2n=4x=28=22m(2sat)+6sm;假花鳞草2n=4x=28=24m(2sat)+4sm;肃草2n=4x=28=22m+6sm(2sat);小颖鹅观草2n=4x=28=22m+6sm(2sat);纤瘦鹅观草2n=4x=28=24m(4sat)+4sm;变颖鹅观草2n=4x=28=20m+8sm(2sat);毛花鹅观草2n=4x=28=24m(2sat)+4sm。它们的核型属1A或2A型。其中后5个物种的核型为首次报道。     

10个四倍体披碱草属物种的核型（简报）

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).     

中国贝母属(Fritillaria)7种植物的核型研究

通过对7种国产贝母属（Fritillaria）植物的染色体核型进行观察和研究,报道了小白花贝母（F.albidoflora Duan&Zheng）、川贝母（F.cirrhosa Don）、伊贝母（F.pallidiflora Schrenk ex Fischer&Meyer）、华西贝母（F.sichuanica Chen）、托里贝母（F.tortifolia Duan&Zheng）、新疆贝母（F.walujewii Regel）、裕民贝母（F.yuminensis Duan）等7种植物的染色体数目及核型,其中3种为首次报道。结果显示,7种国产贝母属植物的核型均具有高度不对称性。此外,小白花贝母与已报道的黄花贝母（F.verticillata Willdenow）的核型存在明显差异,提示Flora of China将小白花贝母归并入黄花贝母的分类处理可能并不恰当,二者的关系需进一步研究。     

中国19种蜡蝉的核型研究(同翅目：蜡蝉总科)

研究了中国19种蜡蝉的染色体数目、性别决定和染色体行为。2n=28(26+XO)被认为是蜡蝉科的原始核型特征。由于蜡蝉精巢具有被膜,减数分裂前期Ⅰ具有弥散期,因此作者认为蜡蝉与半翅目的关系更为密切。     

Karyotypes of three species of the family Cottidae (Scorpaeniformes)

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.     

Karyotypes and sex determination in two species of laelapid mites (Acari: Gamasida)

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.     

Karyotypes of eight species of phytoseiid mites (Acarina: Mesostigmata) from Madagascar

Haplo-diploidy was found to be regular with eight species of phytoseiid mites occurring in Madagascar. The chromosome number in all species was n=4. A variation was found with respect to centromere position.     

Karyotypes and sex determination of ten species of phytoseiid mites (acarina: Mesostigmata)

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.     

Karyotypes of tragopogon (Compositae: Lactuceae)

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.     

Karyotypes of eight species of Euphorbia L. (Euphorbiaceae) from China

In this paper, eight species of the genus Euphorbia L. were cytologically studied. The three species of the subgenus Chamaesyce Raf., E. hirta, E. humifusa and E. hypericifolia, had chromosome numbers of 2n = 18, 22 and 32, with their basic chromosome numbers being x = 9, 11 and 8 respectively. The two species of the subgenus Poinsettia (Grah.) House. E. dentata, with 2n=28, a tetraploid, and E. cyathophora, with 2n= 56, a octoploid, had both the basic chromosome number of x= 7. The three species of the subgenus Esula Pers, E. lathyris, E. helioscopia and E. hylonoma, had chromosome number of 2n= 20, 42 and 20, with their basic numbers being x= 10, 7 and 10 respectively. The basic chromosome number of x = 8 is new for E. hypericifolia, in which x = 7 was previously reported. This indicates that this species had both ploidy(2n = 4x = 28, 8x = 56) and dysploidy(x = 7, 8) variations. In E. dentata, there occurred also ploidy variation (2n = 2x, 4x and 8x). A tetraploid cytotype of E. esula was found in China, its diploid cytotype and hexaploid cytotype being previously reported in North America, the Iberian Peninsula and some other European areas. Based on our results and those previously reported, we support the viewpoint that x＝10 may be the original basic chromosome number of Euphorbiaand discuss the role of polyploidy and dysploidy in the speciation and evolution of this genus     

3种甘草属植物的核型研究

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。     

八种国产大戟属植物的核型报道

8种大戟属Euphorbia L．植物的核型分析结果表明,大戟属不同亚属的染色体基数与其形态变 异的复杂性有一定关系。地锦草亚属subgen．Chamaesyce 3个种染色体基数分别为x=8,9,11;一品红 亚属subgen．Poinsettia两个种染色体基数均为x=7,分别为四倍体和八倍体;乳浆大戟亚属subgen． Esula 3个种,染色体基数分别为x=7,10,10。根据以前学者发表的资料分析,一品红亚属和大戟亚属 Subgen. Euphorbia的染色体基数是很稳定的,分别为x=7和x=10;通奶草E．hypericifolia为x=8 的四倍体,它不仅有染色体整倍性的变异,还有异基数性的变化。结合以前学者的研究,笔者支持x= 10为大戟属的最原始基数的观点。齿裂大戟E．dentata和通奶草具不同的染色体倍性,猫眼草E． esula的细胞染色体数目观察证实了我国存在四倍体的居群,与欧洲和北美的植物构成一个典型的多倍体复合体。     

Ethiopian mistletoes: new species and combinations

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.     

11个四倍体赖草属物种的核型研究

对11个四倍体赖草属Leymus Hochst.物种的核型进行了研究,核型公式如下：沙生赖草L. arenarius (L.) Hochst., 2n=4x=28=18m+4sm+6st (4sat); 密穗赖草L. condensatus (J. Presl) A. Lve, 2n=4x=28=22m+4sm (2sat)+2st (2sat); 新生赖草L. innovatus (Beal) Pilg., 2n=4x=28=24m (4sat) +4sm (2sat);多枝赖草L. multicau     

Karyotypes of four species of chironomids (Diptera, Chironomidae) from Northern Italy

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.