Genome analysis of Elytrigia caespitosa, Lophopyrum nodosum, Pseudoroegneria geniculata ssp. scythica, and Thinopyrum intermedium (Triticeae: Gramineae).

To elucidate the genome constitutions of the tetraploid (2n = 4x = 28) species Elytrigia caespitosa, Lophopyrum nodosum, and Pseudoroegneria geniculata ssp. scythica and the hexaploid (2n = 6x = 42) Thinopyrum intermedium, meiotic pairing was studied in these species as well as 10 hybrids. Karyotype analysis with aceto-orcein stained root-tip cells was performed for the four species and the hybrids of T. bessarabicum with E. caespitosa, P. geniculata ssp. scythica, and T. intermedium. Karyotype analysis by Giemsa C-banding was carried out with the three tetraploid species and the two triploid hybrids involving T. bessarabicum. The species behaved as strict allopolyploids. All hybrids were male sterile with few stainable pollen grains. It is concluded from the results that the three tetraploid species have the genome formula JeJeSS and T. intermedium has the formula JeJeJeJeSS. The chromosomes of the Je and S genomes in these species had C-banding patterns differing from each other and from those of the extant diploid species. Based on these findings, the four species investigated should be placed in the same genus or the same section of a genus. However, new combinations are not proposed at this time pending future taxonomic investigation of the genome constitution of Elytrigia repens (L.) Nevski.     

中国四齿藓科的订正

对中国四齿藓科的分类及分布进行了全面研究。据陈邦杰等前人报道,本科在中国分布仅１属１种。现经作者们搜集到的２３６份中国四齿藓科标本（原均被鉴定为四齿藓ＴｅｔｒａｐｈｉｓｐｅｌｕｃｉｄａＨｅｄｗ．）,重新解剖观察后鉴定,发现除原有之广布种四齿藓外,尚有此次新发现的中国新分布种：疣柄四齿藓ＴｅｔｒａｐｈｉｓｇｅｎｉｃｕｌａｔａＧｉｒｇ,另有傅星及高谦等在川西发现新分布原丝藓Ｔｅｔｒｏｄｏｎｔｉｕｍｂｒｏｗｎｉａｎｕｍ（Ｄｉｃｋｓ）Ｓｃｈｗａｅｇｒ．,以及Ｈ．Ｖｉｌ和曹同在吉林发现的无助原丝藓Ｔｅｔｒｏｄｏｎｔｉｕｍｒｅｐａｎｄｕｍ（ＦｕｎｃｋｅｘＳｔｕｒｍ）Ｓｃｈｗａｅｇｒ．,故本科在中国分布增至２属４种,本文对此４种在中国及世界分布均进行了讨论。     

Contributions to the cytòtaxonomy of the Commelinaceae

Representatives of the Tradescantia geniculata alliance (genus Gibasis Rafin.) in cultivation at Kew display considerable cytological and morphological diversity. Chromosome complements consist of either large or small chromosomeS. Plants with small chromosomes have either 2 n = 16 or 2 n = 32, and all form only bivalents at meiosis and have presumed basic numbers of x – 8 and x = 8 or 16 respectively. The 2 n = 32 accessions are considered to represent T.geniculata in its strict sense; the identity of the 2 n =16 plant is uncertain. Plants with large chromosomes have either 2 n = 16 or 2n = 20 and each forms quadrivalents to the extent that they can be considered as cytological autotetraploidS. Basic numbers are then x = 4 and x =5, the lowest yet recorded for the Commelinaceae. The identity of the x = 4 species is uncertain. The x = 5 plants are readily identified as T.karwinskyana.     

西沙群岛的腐生半知菌

Fourteen species of saprotrophic fungi isolated from various substrates from Xisha Islands are reported, including a new record species-Curvlaria tuberculata Jain. The others are: Alternaria alternata (Fr.) Keissler. A. phragmospora van. Emden, Aspergillus niger van. Tiegh., Cladosporium arysporum Berk. & Curt., C sphaerospormum Penz., Curvularia affinis Boedijn, C. geniculata (Tracy & Earle) Boedijn, C. lunata (Walk.) Boedijn, Exserohilium turcicum (Pass.) Leonard & Suggs.,Humicola grisea Traaen, Botryodip…     

拟鹅观草属3种植物的核型研究

对禾本科小麦族拟鹅观草属物种Pseudoroegneria geniculata、P.geniculata ssp.scythica和P.geniculata ssp.pruinifera的核型进行了研究.结果显示:P.geniculata和P.geniculata ssp.scythica为四倍体物种,P.geniculata ssp.pruinifera为六倍体物种;P.geniculata、P.geniculata ssp.scythica和P.geniculata ssp.pruinifera的核型公式分别为2n=4x=28=18m(2sat)+10sm(2sat)、2n=4x=28=28m(2sat)和2n=6x=42=36m(6sat)+6sm(2sat);P.geniculata和P.geniculata ssp.pruinifera为2A核型,而P.geniculata ssp.scythica为1A核型.研究表明:3种植物的核型存在差异;P.geniculata ssp.pruinifera的核型为首次报道,其核型明显不同于P.geniculata和P.geniculata ssp.scythica.     

The esterase activity of a pigmented bacterial group belonging to the Pseudomonas genus

Bacteria belonging to the Pseudomonas genus and isolated from zonal soils in different geographical zones of the USSR as well as from the rhizosphere of cultivated and wild plants were tested for their esterase activity. The studied collection of cultures included 205 strains of different pigmented Pseudomonas species which, according to the conventional taxonomy, were assigned to the so-called "Pseudomonas fluorescens complex". As was shown in this study, many Pseudomonas species are potential producers of nonspecific esterases. P. maltophilia and P. geniculata synthesizing pyomelanin have the highest activity of esterase. The activity of esterase correlates with the formation of a melanin-like pigment in Pseudomonas cultures. It also correlates with the species to which a culture belongs, which makes it possible to use this property as an additional criterion for the identification of Pseudomonas species.     

Three New “Biological” Species of Tetrahymena (T. hegewischi n. sp., T. sonneborni n. sp., T. nipissingi n. sp.) and Temperature Tolerance of Members of the “pyriformis” Complex1

Stocks of the Tetrahymena pyriformis complex have been collected in North America and their mating reactivity has been studied. In addition to stocks mating with Tetrahymena americanis, T. borealis, T. pigmentosa, T. hyperangularis, and T. australis, stocks belonging to old syngen 5 and three new mating groups, numbers 13, 14, and 15, were discovered. Syngen 5 and groups 13 and 14 are distinct “biological” species, based on their reproductive isolation from other groups and on the ability of withingroup crosses to produce immature progeny. These species have been named T. hegewischi n. sp., T. sonneborni n. sp., and T. nipissingi n. sp., respectively. The cross between the two group 15 stocks did not produce immature progeny, and there is not sufficient evidence to conclude that this pair of stocks represents a separate species. Temperature tolerance measurements have been made on stocks representing all known micronucleate members of “pyriformis” complex. Within each species, the range of temperature tolerances is narrow; the average within-species standard deviation is 0.63°C. The species averages range from 32.7 to 40.7°C. Using syngen numbers, the order from lowest to highest temperature tolerance is 9, 8, 10, 7, 6, 4, 13, 14, 12, 11, 5, 3, 2, 1. The large differences among species make temperature tolerance a useful aid in identification, but the origins of the differences among species are unknown.     

Hybridisation in the genera Vulpia and Festuca: the production of artificial F1 plants

The results of hybridisation experiments involving 24 strains of diploid, tetraploid and hexaploid Vulpia , representing nine species in three sections, and 22 strains of hexaploid and octoploid Festuca rubra agg., are presented, and the taxonomic implications discussed. 7848 pollinations produced 741 hybrid caryopses, from which 137 mature hybrid plants were raised (1.75% success rate) by embryo culture. Festuca x Festuca crosses were relatively easily achieved, and Festuca x Vulpia crosses were as successful as Vulpia x Vulpia crosses, indicating a close relationship between these two genera. Hybrids with F. rubra agg. were raised from females of species from all three sections of Vulpia. Within Vulpia , the most successful crosses involved V. geniculata, V. ligustica, V. fasciculata and V. pyramidata , whereas V. alopecuros was the least successful parent of all, producing only one mature hybrid from 2595 pollinations.     

Presence of 3-O-methyl-l-xylose in the lipopolysaccharide of Pseudomonas maltophilia N.C.T.C. 10257.

3-O-Methyl-L-xylose was isolated from whole cells of Pseudomonas maltophilia N.C.T.C. 10257. The sugar is a component of lipopolysaccharide from which a polysaccharide also containing L-rhamnose and L-xylose was released by mild acid hydrolysis. 3-O-Methyl-L-xylose was absent from five other strains of Ps. maltophilia and one strain of Pseudomonas geniculata.     

Co-existence of salt and drought tolerance in Triticeae

Cell membrane stability (CMS) technique was used to screen for drought tolerance, salt tolerant accessions of three Aegilops species, Ae. tauschii, Ae. cylindrica, Ae. geniculata and two hexaploid wheat (Tricitum aestivum L.) cultivars comprising salt tolerant LU-26 and drought tolerant Chakwal-86. The objectives were to see how valid it is for a salt tolerant plant to be drought tolerant as well and to identify the character(s) that may contribute to drought tolerance. Three moisture levels equal to 100, 50 and 25% saturation capacity of the soil were used for plant cultivation. Injury percentage (IP) based on in-vitro desiccation induced by polyethylene glycol (PEG) in leaf tissue was measured through the conductivity of the electrolyte leakage. Injury percentage decreased in all the test material with decrease in soil moisture contents. Ae. cylindrica exhibited minimum injury at 100% soil moisture level followed by Ae. tauschii and Ae. geniculata while drought tolerant wheat cultivars exhibited the maximum. The wheat cultivar Chakwal-86 has been developed for dry areas, with low soil moisture levels, and high water potential enhances the injury percentage. Aegilops cylindrica is a salt tolerant species and can thus tolerate water deficit conditions created due to low osmotic potential. Potassium appeared to play an important role in drought tolerance which was evident from high K+ contents and low K+ leakage from Aegilops cylindrica and drought tolerant wheat cultivar Chakwal-86. It was inferred from the study that salt tolerant species might prove drought tolerant in the areas where water deficit prevails due to the ability to create low intracellular osmotic potentials.     

Genome sequence of a novel nicotine-degrading strain, Pseudomonas geniculata N1

A newly isolated bacterium, Pseudomonas geniculata N1, can efficiently degrade nicotine. Here we present a 4.51-Mb assembly of its genome, which is the first sequence of the P. geniculata group. The sequence contains the genes related to nicotine catabolism and may provide insights into its molecular mechanism for N-heterocyclic degradation.     

四膜虫S1株——上海四膜虫,新种

四膜虫S1是一株自接型四膜虫,根据形态特征应属梨形四膜虫复合种。本种除克隆内接合外,和其它十二种四膜虫均不接合。本种的异柠檬酸脱氢酶,四唑氧化酶,谷氨酸脱氢酶和乙酸酯酶的同功酶谱和其它十二种四膜虫相比,差异明显。此外,金亦石等(1987)所提供的S1和其它十种四膜虫的rDNA分子的四种限制性内切酶图谱也说明,S1株与除T.australis以外的其它九种的酶切图谱是显著不同的。据此,作者认为本种应是梨形四膜虫复合种中一新种,并定名为上海四膜虫。     

Characterization of chromosome-specific S-SAP markers and their use in studying genetic diversity in Aegilops species.

The short interspersed nuclear element (SINE), Au, was used to develop sequence-specific amplified polymorphism (S-SAP) markers for U- and M-genome chromosomes. The markers were localized using Triticum aestivum (wheat)-- Aegilops geniculata and wheat-- Aegilops biuncialis disomic chromosome addition lines. Thirty-seven markers distributed over 6 U and 6 M chromosomes were produced. A genetic diversity study carried out on 37 accessions from Ae. biuncialis, Ae. comosa, Ae. geniculata, and Ae. umbellulata suggested that Ae. biuncialis have arisen from its diploid ancestors more recently than Ae. geniculata. Several earlier studies indicated that the M genomes in polyploid Aegilops species had accumulated substantial rearrangements, whereas the U genomes remained essentially unmodified. However, this cannot be attributed to the preferential insertion of retroelements into the M genome chromosomes. Fourteen markers from a total of 8 chromosomes were sequenced; 3 markers were similar to known plant genes, 1 was derived from a long terminal repeat (LTR) retrotransposon, and 10 markers did not match to any known DNA sequences, suggesting that they were located in the highly variable intergenic regions.     

Genome constitutions of Thinopyrum curvifolium, T. scirpeum, T. distichum, and T. junceum (Triticeae: Gramineae).

The objective of this study is to elucidate genome constitutions of Thinopyrum curvifolium (Lange) D.R. Dewey, T. scirpeum (K. Presl) D.R. Dewey, T. distichum (Thunb.) A. L?ve, and T. junceum (L.) A. L?ve. Hybrids of T. sartorii (Boiss. &Heidr.) A. L?ve with T. scirpeum and T. junceum, as well as the hybrid between T. curvifolium and Pseudoroegneria geniculata ssp. scythica (Nevski) A. L?ve, were made and chromosome pairing at metaphase I was studied. The karyotype analyses of mitotic cells stained by aceto-orcein were conducted for both hybrids and the four target species. The Giemsa C-banding following acetocarmine staining was carried out for the above species and the triploid hybrid T. curvifolium x T. bessarabicum (Savul &Rayss) A. L?ve. Meiotic data indicate that all target species have two sets of the basic genome J, but they behave like true allopolyploids because of bivalentization. Karyotypes of T. curvifolium and its triploid hybrid with T. bessarabicum indicate that T. curvifolium contains two different versions of the Jb genome, designated as Jb3 and Jb4, rather than two Je genomes as previously believed. Thinopyrum scirpeum and T. elongatum (4x) have similar karyotypes. Both are segmental allotetraploids carrying two forms of the Je genome. Their genome formulae are Je2 Je3 and Je1 Je3, respectively. Thinopyrum distichum has a karyotype similar to T. junceiforme, which has the Jb2 Je2 genome formula. However, the two species differ in C-banding patterns, reflecting their geographical separation. Thinopyrum junceum is a hexaploid with two pairs of Jb2 genomes and one pair of the Je2 genome, and it has a C-banding pattern similar to that of T. junceiforme, which has one pair each of the Jb2 and Je2 genomes.     

Notes on Thysanoptera found on flax (Linum usitatissimum L.) in the British Isles

The following eighteen species of Thysanoptera Terebrantia have been found on flax in the British Isles: Melanthrips fuscus (Sulzer), Aeolothrips fasciatus (L.), Anaphothrips obscurus (Müler), Aptinothrips rufus (Gmelin), Chirothrips manicatus Hal., Limothrips cerealium Hal., L. denticornis Hal., Stenothrips graminum Uzel, Taeniothrips atratus (Hal.), T. vulgatissimus (Hal.), Thrips angusticeps Uzel, T. discolor Hal., T. flavus Schrank, T. fuscipennis Hal., T. major Uzel, T. minutissimus L., T. physapus L., T. tabaci Lindeman. Each species is described briefly with notes on habits of adults and larvae, place of pupation, number of generations in the year, hibernation, time of occurrence on plants, plants and objects on which found, host plants of larvae and adults, importance to flax, record of locality and collector on flax, distribution, including altitudes, in the British Isles. More species occur in the south than in the north of Great Britain, and species common to both regions usually occur in greater numbers in the south. The insects breed on certain species of crop plants, weeds or trees of arable land. No damage of economic importance to flax by Thysanoptera has been proven in the British Isles, and the flax thrips, Thrips lini Ladureau, has not been found. Taeniothrips vulgatissimus (Hal.) may breed on flax and its adults, and those of T. atratus (Hal.) may cause superficial damage to petals of flowers. Thrips angusticeps Uzel and T. tabaci Lindeman will probably breed on flax.     

Obelin from the bioluminescent marine hydroid Obelia geniculata: cloning, expression, and comparison of some properties with those of other Ca2+-regulated photoproteins

A cDNA encoding the Ca2+-regulated photoprotein of the bioluminescent marine hydroid Obelia geniculata was cloned and sequenced. The cDNA is a 774 bp fragment containing two overlapping open reading frames, one of which contained 585 bp encoding a 195 amino acid polypeptide which obviously has the primary structure of the apoprotein of a calcium-regulated photoprotein. Many of the residues are identical to those in other Ca2+-regulated photoproteins: 86% compared with that from Obelia longissima, 76% with that from Clytia (Phialidium), 64% with that from Aequorea, and 64% with that from Mitrocoma(Halistaura). The obelin from O. geniculata was overexpressed in Escherichia coli, refolded from inclusion bodies, and purified. The yield of highly purified recombinant protein was 55-80 mg/L of LB medium. O. geniculata obelin has absorption maxima at 280 and 460 nm and a shoulder at approximately 310 nm. The calcium-discharged protein loses visible absorption but exhibits a new absorption maximum at 343 nm. The bioluminescence of the obelin from O. geniculata is blue (lambda(max) = 495 nm). In contrast, the fluorescence of the calcium-discharged protein is yellow-green (lambda(max) = 520 nm; excitation at 340 nm). This is in sharp contrast to aequorin in which the bioluminescence and fluorescence emission spectra of the calcium-discharged protein are almost identical (lambda(max) = 465 nm). The Ca2+ concentration-effect curve for O. geniculata obelin is similar to those of many other photoproteins: at [Ca2+] below approximately 10(-8) M, calcium-independent luminescence is observed, and at [Ca2+] approximately 10(-3) M, the luminescence reaches a maximum. Between these extremes, the curve spans a vertical range of almost 8 log units with a maximum slope on a log-log plot of about 2.5. In the absence of Mg2+ the rate constant for the rise of bioluminescence determined by the stopped-flow technique is about 450 s(-1). The effects of Mg2+ on the kinetics of bioluminescence are complicated, but at all concentrations studied they are relatively small compared to the corresponding effects on aequorin luminescence. At least with respect to speed and sensitivity to Mg2+, the obelins from both O. longissima and O. geniculata would appear to be more suitable than aequorin for use as intracellular Ca2+ indicators.     

中国块菌要览及其保护策略

截至目前报道的中国块菌有28种,其中黑块菌4种,白块菌24种.具有重要经济价值和生态价值的黑块菌类有印度块菌复合种和中国夏块菌,其中印度块菌复合种与欧洲法国黑孢块菌属于姊妹类群,中国夏块菌与欧洲夏块菌也是姊妹类群.虽然欧洲意大利白块菌在中国尚未找到、波氏块菌在中国的存在尚待最终确认,但是,最近的更多白块菌新种的发现,说...     

中国美姿藓属植物的订正

根据文献记载,中国美姿藓属Ｔｉｍｍｉａ Ｈｅｄｗ。植物共有４种。通过实地采集和标本鉴定,确认中国产苔藓植物共有５种,其中的纤细美姿藓为中国新记录。本文对该属每种植物进行了描述,并给出了分种检索表,同时对它们的分类特征、地理分布也进行了简要讨论。