Chromosome numbers and karyotypes of South American species and populations of Hypochaeris (Asteraceae)

One hundred and thirty-seven new chromosome counts are reported from 104 populations of 26 native South American taxa of Hypochaeris (Asteraceae, Lactuceae), together with two invasive Mediterranean species: H. glabra and H. radicata . First reports are provided for seven taxa ( H. alba , H. cf. eremophila , H. caespitosa , H. hookeri , H. parodii , H. patagonica and H. pinnatifida ) and one new ploidy level is reported (diploid for H. incana , so far known only as a tetraploid). Including the results of this study, the chromosomes of 39 of the c . 50 Hypochaeris species known from the New World have now been counted. Most species are diploid with 2 n  = 2 x  = 8 and have bimodal, asymmetrical karyotypes. Tetraploidy (2 n  = 4 x  = 16) is reported here for the first time in H. caespitosa . Infra-specific polyploidy (probably autopolyploidy) is reported in H. incana and H. taraxacoides , both cases including infra-populational cytotype mixtures (2 x and 4 x ). Polyploidy is now known from eight South American Hypochaeris species ( c . 16%). Basic karyotype analyses allow the placement of the newly counted taxa into previously proposed but slightly modified groupings and provide the framework for further molecular cytogenetic analyses. The reported findings suggest that chromosomal change in South American Hypochaeris , in contrast to Old World species, has not involved aneuploidy, but polyploidy and/or more subtle changes in chromosome length, perhaps via satellite DNA amplification/deletion or activity of retroelements, and rDNA reorganization.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 49–60.     

中国毛膝蝇属研究并记四新种(双翅目,蝇科)

记述分布于我国的蝇科Muscidae圆蝇亚科Mydaeinae中的毛膝蝇属Hebemema Sdmabl,1889已知种类,共9种,其中有4新种:毛眼毛膝蝇H.dasyopos.nov.,玛纳斯毛膝蝇H.manasicus sp.nov.,隐颜毛膝蝇 H.invisifacies sp.nov.和西蜀毛膝蝇 H.xishuicum sp.nov.,对其形态特征进行了详细描述,编制了该属中国已知种检索表.前2种模式标本藏于军事医学科学院微生物流行病研究所医学昆虫标本馆;后2种藏于中国科学院上海植物生理生态研究所昆虫博物馆.     

中国一种新归化植物——菱叶苋

报道中国新记录种--菱叶苋(Amaranthus standleyanus Parodi ex Covas),该种原产阿根廷,近来成为北京地区一种归化杂草。     

Pollen size in Hordeum L.: correlation between size,ploidy level,and breeding system

The size of pollen in the genus Hordeum (Poaceae) is correlated with ploidy level and breeding system. Generally, the pollen size increases with the ploidy level, and outbreeding species possess significantly larger pollen than inbreeders. In H. roshevitzii (2x), H. pusilplum (2x), H. murinum subsp. murinum (4x), and H. parodii (6x) pollen, heteromorphisms occur between the central and the lateral florets of the triplet. In all four taxa, pollen from florets in which the anthers are exserted is larger than pollen from florets where the anthers remain inside the floret. The biological consequences of heteromorphic pollen are discussed, and a model for the evolution of breeding strategies in Hordeum is suggested.     

Cytoembryology of some Malaysian dipterocarps, with some evidence of apomixis

KAUR, A., JONG, K., SANDS, V. E. & SOEPADMO, E., 1986. Cytoembryology of some Malaysian dipterocarps, with some evidence of apomixis. Embryological and cytological studies on some members of the Dipterocarpaceae were undertaken. Of the dipterocarps investigated 83% were diploids. Two new polyploids were observed, namely Shorea resinosa (2 n = 3x = 21) and Hopea subalata (2 n = 3x = 21). Multiple seedlings were observed in H. subalata, Shorea agami, S. argentifolia, S. ovalis, S. pauciflora and S. resinosa. For the first time embryological studies have conclusively demonstrated reproduction by agamospermy in 5. ovalis and S. agami. Considerable evidence leads to the inference that H. subalata, S. resinosa and 5. macroptera are also agamosperms. Each of these produces multiple seedlings. Of these apomictic species three are polyploids, namely S. ovalis (2 n = 4x = 28), H. subalata (2 n = 3x = 21) and S. resinosa (2 n = 3x = 21), whereas S. agami (2 n = 14) and S. macroptera (2 n = 14) are diploids.     

The genomic composition of Tricepiro, a synthetic forage crop.

Chromosome in situ hybridization (FISH and GISH) is a powerful tool for determining the chromosomal location of specific sequences and for analysing genome organization and evolution. Tricepiro (2n = 6x = 42) is a synthetic cereal obtained by G. Covas in Argentina (1972), which crosses hexaploid triticale (2n = 6x = 42) and octoploid Trigopiro (2n = 8x = 56). Several years of breeding produced a forage crop with valuable characteristics from Secale, Triticum, and Thinopyrum. The aim of this work is to analyse the real genomic constitution of this important synthetic crop. In situ hybridization using total DNA of Secale, Triticum, and Thinopyrum as a probe (GISH) labelled with biotin and (or) digoxigenin showed that tricepiro is composed of 14 rye chromosomes and 28 wheat chromosomes. Small zones of introgression of Thinopyrum on wheat chromosomes were detected. The FISH using the rye repetitive DNA probe pSc 119.2 labelled with biotin let us characterize the seven pairs of rye chromosomes. Moreover, several wheat chromosomes belonging to A and B genomes were distinguished. Therefore, tricepiro is a synthetic hexaploid (2n = 6x = 42) being AABBRR in its genomic composition, with zones of introgression of Thinopyrum in the A genome of wheat.     

香港喜盐草属植物的核型分析

报道了分布于我国香港特别行政区的喜盐草属(Halophila Thou.) 2种植物的染色体数目和核型,其体细胞中期染色体数目均为2n=18。它们的核型公式分别为：喜盐草(H. ovalis (R. Br.) Hook. f.) 2n=2x=18=4m+14sm;贝克喜盐草(H. beccarii Asch) 2n=2x=18=8m+10sm(首次报道)。核型均属于2B型。     

Cytology of ten species in Anemone,one in Anemoclema and six in Clematis (Trib. Anemoneae,Ranunculaceae) from China

The somatic chromosome number and detailed chromosome morphology have been studied in ten species of Anemone, one species of Anemoclema, and six species of Clematis, all from China, namely Anemone davidii Franch. (2n=4x= 32), A. stolonifera Maxim. (2n=2x=16), A. flaccida Fr. Schmidt (2n=2x= 14), A. rivularis Buch.-Ham. (2n=2x= 16), A. begoniifiolia lévl. et Vant. (2n=2x= 16), A. hupehensis Lem. f. alba W. T. Wang (2n =2x = 16), A. tomentosa (Maxim.) Péi (2n=2x= 16), A. rupestris Hook. f. et Thoms. (2n=2x= 14), A. trullifolia var. colestina (Franch.) Finet et Gagnep. (2n = 2x = 14), A. trullifolia var. holophylla Diels (2n=2x= 14), A. demissa Hook. f. et Thoms. (2n=2x= 14), Anemoclema glaucifolium (Franch.) W. T. Wang (2n= 2x= 16), Clematis kockiana Schneid. (2n= 2x=16), C. rehderiana Craib. (2n = 2x = 16), C. ranunculoides Franch. (2n = 2x = 16), C. puberula var. ganpiniana(Lévl. et Vant. ) W. T. Wang (2n = 2x = 16), C. brevicaudata DC. (2n= 2x= 16), C. chrysocoma Franch. (2n = 2x = 16). The species of x = 8 in Anemone, and those in Anemoclema and Clematis have very similar karyotypes which consist of five pairs of large median-centromeric (rarely one pair of which are submedian-centromeric) and three pairs of subterminalor terminal-centromeric chromosomes.     

Haematozoa of fishes in Humboldt Bay, California.

Five hundred seven fish representing 45 species from Humboldt Bay, California (USA) were examined for blood parasites. Four fish (less than 1%) from two species were infected. Haemogregarina leptocotti sp. n. is described from one of 33 staghorn sculpin (Leptocottus armatus). Haemogregarina roelofsi sp. n. is described from three of 15 black rockfish (Sebastes melanops). Gametocytes of H. leptocotti sp. n. averaged 6.1 x 2.1 microns with a 2.7 x 1.7 microns oval nucleus; those of H. roelofsi sp. n. averaged 5.5 x 2.7 microns with a 2.5 x 2.2 microns rectangular nucleus. Neither species of parasite had distinct chromatin granules, a polar cap, or more than one gametocyte in an infected cell. Haematozoa are relatively rare in fishes of the northeastern Pacific Ocean.     

Intergeneric crosses of Psathyrostachys huashanica with Elymus spp. and cytogenetic studies of the hybrids with E. tsukushiensis (Poaceae, Triticeae)

Intergeneric crosses have been made between Psathyrostachys huashanica (2x= 14, NN) and three Elymus species, namely, E. pendulinus (2n = 4x = 28, SSYY), E. ciliaris (2n = 4x = 28, SSYY), and E. tsukushiensis (2n = 6x = 42, SSHHYY). Three accessions of E. tsukushiensis from different localities crossed with P. huashanica produced adult hybrid plants. Although completely sterile, the hybrid plants developed rather vigorously, and were morphologically intermediate between the two parents. Chromosome configuration of 24.62I + 1.51II + 0.03III per cell characterized meioses of the hybrids, but there existed slight variations among different combinations. These results indicate that there is little or no chromosome homoeology between "N" genome of P. huashanica and "S", "H" or "Y" genomes of E. tsukushiensis.     

Genomic constitutions of four Chinese endemic Elymus species: E. brevipes, E. yangii, E. anthosachnoides, and E. altissimus (Triticeae, Poaceae).

The objectives of this study were to determine the genomic constitution and to explore the genomic variation within four Chinese endemic Elymus species, i.e., E. brevipes (Keng) L?ve (2n = 4x = 28) and E. yangii B.R. Lu (2n = 4x = 28), E. anthosachnoides (Keng) L?ve (2n = 4x = 28), and E. altissimus (Keng) L?ve (2n = 4x = 28). Intraspecific crosses between different populations of the four Elymus species, as well as interspecific hybridizations among the four target species, and with six analyzer species containing well-known genomes, i.e., E. caninus (L.) L. (2n = 4x = 28, SH), E. sibiricus L. (2n = 4x = 28, SH), E. semicostatus (Lees ex Steud.) Melderis (2n = 4x = 28, SY), E. parviglumis (Keng) L?ve (2n = 4x = 28, SY), E. tsukushiensis Honda (2n = 6x = 42, SHY), and E. himalayanus (Nevski) Tzvelev (2n = 6x = 42, SHY), were achieved through the aid of embryo rescue. Chromosome pairing behaviors were studied in the parental species and their hybrids. Numerical analysis on chromosome pairing was made on the interspecific hybrids. With one exception, each meiotic configuration at metaphase I in the hybrids involving the target taxa and the analyzer species containing the "SH" genomes fit a 2:1:1 model with x-values ranging between 0.91 and 1.00; chromosome pairing in the hybrids involving analyzer parents with the "SY" genomes match a 2:2 model, with x-values between 0.97 and 0.99. All pentaploid hybrids with a genomic formula "SSYYH," except for two crosses having unexpected low c-values, had pairing patterns fitting the 2:2:1 model with x-values varying between 0.96 and 1.00. It is concluded based on hybridization, fertility, and chromosome pairing data that (i) the four target Elymus species are strictly allotetraploid taxa, (ii) they are closely related species, all comprised of the "SY" genomes, (iii) minor genomic structural rearrangements have occurred within the four Elymus species, and (iv) meiotic pairing regulator(s) exists in some of the Elymus taxa studied.     

Cytotaxonomy of the genusPolystichum in the Western Himalayas

Cytotaxonomical investigations on 11 species from the Western Himalayas show that 8 are diploid and the remaining tetraploid. The numbers for three species are new.P. prescottianum (2x) andP. thomsoni (4x), andP. stimulans (2x) andP. acanthophyllum (4x) are closely related but distinct species pairs.     

准噶尔盆地东南缘不同生境条件下梭梭群落结构特征研究

在新疆准噶尔盆地东南缘,以平缓低洼地、平缓沙地、半流动沙丘等3种不同生境类型上的天然梭梭群落为研究对象,从物种结构、物种多样性、生物量以及梭梭天然更新幼苗幼树种群分布格局等方面,研究不同生境条件下梭梭群落的结构特征.结果表明,以平缓低洼地上梭梭群落的植物种类最丰富,其次是平缓沙地,半流动沙丘上的植物种类最少.3种生境类型上群落中的植物种类分别为1种、15种和12种;梭梭天然更新幼苗幼树以半流动沙丘上的梭梭群落为最多,达 87株·hm^-2,但幼苗幼树在梭梭群落内分布不均匀,平缓低洼地上梭梭群落内的幼苗幼树比半流动沙丘上的略少,为5 799株·hm^-2,但幼苗幼树在梭梭群落内分布均匀,总体评价以平缓低洼地上梭梭群落的天然更新最好;平缓低洼地上梭梭群落的总生物量为19.39 t·hm^-2,平缓沙地上为9.32 t·hm^-2,半流动沙丘上为.9 t·hm^-2;不同生境类型上梭梭群落天然更新幼苗幼树的分布格局均为聚集分布.平缓低洼地地面固定,土壤水分和肥力较好,比较适宜梭梭林木生长和梭梭群落的发育,平缓沙地和半流动沙丘的地面容易产生风蚀,土壤水分和肥力较差,生境条件比较严酷.     

Protective activity of propofol,Diprivan and intralipid against active oxygen species.

We separately studied the antioxidant properties of propofol (PPF), Diprivan (the commercial form of PPF) and intralipid (IL) (the vehicle solution of PPF in Diprivan) on active oxygen species produced by phorbol myristate acetate (10(-6) M)-stimulated human polymorphonuclear leukocytes (PMN: 5 x 10(5) cells/assay), human endothelial cells (5 x 10(5) cells/assay) or cell-free systems (NaOCl or H2O2/peroxidase systems), using luminol (10(-4) M)-enhanced chemiluminescence (CL). We also studied the protective effects of Diprivan on endothelial cells submitted to an oxidant stress induced by H2O2/MPO system: cytotoxicity was assessed by the release of preincorporated 51Cr. Propofol inhibited the CL produced by stimulated PMN in a dose dependent manner (until 5 x 10(-5) M, a clinically relevant concentration), while Diprivan and IL were not dose-dependent inhibitors. The CL produced by endothelial cells was dose-dependently inhibited by Diprivan and PPF, and weakly by IL (not dose-dependent). In cell free systems, dose-dependent inhibitions were obtained for the three products with a lower effect for IL. Diprivan efficaciously protected endothelial cells submitted to an oxidant stress, while IL was ineffective. By HPLC, we demonstrated that PPF was not incorporated into the cells. The drug thus acted by scavenging the active oxygen species released in the extracellular medium. IL acted in the same manner, but was a less powerful antioxidant.     

Molecular phylogeny of the genus Hordeum using three chloroplast DNA sequences.

The genus Hordeum consists of three cytotypes (2x, 4x, and 6x). Its reproductive isolation has been incomplete between closely related species and hence the genetic relationship is reticulate and complex. We used 32 taxa of Hordeum and three chloroplast DNA sequences, matK, atpB-rbcL, and trnL-trnF in the current study. Molecular phylogenetic analysis based on sequence data of the three chloroplast DNA regions clearly demonstrated genetic relationships among taxa and origin of polypoids. The formation of H. secalinum likely involved hybridization between Hordeum marinum subsp. marinum and a Eurasian diploid possessing the H genome. The formation of hexaploid Hordeum brachyantherum involved hybridization between tetraploid H. brachyantherum and diploid H. marinum subsp. gussoneanum. The formation of three tetraploids, H. brachyantherum, Hordeum jubatum, and Hordeum guatemalense, probably involved hybridization between H. brachyantherum subsp. californicum and an altered H genome diploid. The formation of Hordeum arizonicum involved the two taxa Hordeum pusillum and H. jubatum.     

Osmium tetroxide, used in the treatment of arthritic joints, is a fast mimic of superoxide dismutase

Aqueous solutions of osmium tetroxide (OsO4) have been injected into arthritic knees for the past 45 years to chemically destroy diseased tissue, in a procedure termed "chemical synovectomy." Arthritis is an inflammatory disease. The primary inflammatory chemical species are the superoxide anion radical (O2.-) and nitric oxide (.NO), which combine to form the peroxynitrite anion (ONOO-). Here we show that OsO4 does not react with ONOO- but very efficiently catalyzes the dismutation of O2.- to O2 and H2O2. Using the pulse-radiolysis technique, the catalytic rate constant has been determined to be (1.43+/-0.04) x 10(9) M-1 s-1, independent of the pH in the 5.1-8.7 range. This value is about half that for the natural Cu,Zn-superoxide dismutase (Cu,Zn-SOD). Per unit mass, OsO4 is about 60 times more active than Cu,Zn-SOD. The catalytically active couple is OsVIII/OsVII, OsVIII oxidizing O2.- to O2 with a bimolecular rate constant of k=(2.6+/-0.1)x10(9) M-1 s-1 and OsVII reducing it to H2O2 with a bimolecular rate constant of (1.0+/-0.1)x10(9) M-1 s-1. Although lower valent osmium species are intrinsically poor catalysts, they are activated through oxidation by O2.- to the catalytic OsVIII/OsVII redox couple. The OsVIII/OsVII catalyst is stable to biochemicals other than proteins and peptides comprising histidine, cysteine, and dithiols.     

国产毛茛科银莲花族十七种植物的细胞学研究

研究了国产毛茛科银莲花族Trib．Anemoneae 17种植物的染色体数目和核型。10种银莲花属 Anemone L．植物中,1种(西南银莲花A．davidii)为x=8的四倍体(2n=4x=32),5种(匍枝银莲花A． stolonifera、草玉梅 A．rivularis、卵叶银莲花A ．begoniifolia、水棉花A．hupehensis f. alba、大火草A．tomen- tosa)为x=8的二倍体(2n=2x=16),4种(鹅掌草A．flaccida、湿地银莲花A．rupestris、蓝匙叶银莲花 A．trullifolia var．colestina、拟条叶银莲花A．trullifolia var．holophylla、展毛银莲花A．demissa)为x=7的 二倍体(2n=2x=14)。罂粟莲花Anemoclema glaucifolium 为x=8的二倍体。6种铁线莲属Clematis L.植 物(滇川铁线莲C．kockiana、长花铁线莲C．rehderiana、毛茛铁线莲C．ranunculoides、扬子铁线莲C． puberula var．ganpiniana、短尾铁线莲C．brevicaudata、金毛铁线莲A．chrysocoma)均为x=8的二倍体。银 莲花属中x=7的种类的核型彼此十分相似,均由6对大型具中部着丝点的染色体和1对具端部着丝点 的染色体组成;x=8的二倍体种类的核型与罂粟莲花属和铁线莲属植物的核型十分相似,均由5对大型 具中部着丝点和3对具端部或近端部着丝点的染色体组成。     

Highly hydroxylated guaianolides of Achillea asiatica and Middle European Achillea species.

From flower heads of Achillea asiatica (L.) Serg., three new guaianolides were isolated by repeated column chromatography and HPLC. The constitution and the stereochemistry of these new, labile compounds were determined by MS, one ((1)H, (13)C, selective (1)H-TOCSY and (1)H-NOESY) and two-dimensional NMR experiments ((1)H, (1)H-COSY, (1)H, (13)C-HSQC, (1)H, (13)C-HMBC). The substances were identified as 8 alpha-angeloxy-2 alpha, 4 alpha,10 beta-trihydroxy-6 beta H,7 alpha H, 11 beta H-1(5)-guaien-12,6 alpha-olide (1), 8 alpha-angeloxy-1 beta,2 beta:4 beta,5 beta-diepoxy-10 beta-hydroxy-6 beta H, 7 alpha H, 11 beta H-12,6 alpha-guaianolide (2) and 8 alpha-angeloxy-4 alpha,10 beta-dihydroxy-2-oxo-6 beta H,7 alpha H, 11 beta H-1(5)-guaien-12,6 alpha-olide (3). They were also detected in Middle European species (Achillea collina, Achillea ceretanica (2x and 4x), Achillea roseoalba, Achillea asplenifolia) by HPLC, TLC and off line MS and have not been described before. The possibility that these compounds might be products of an oxidation process is discussed.