中国特有植物金铁锁的细胞学研究

In this paper, Psammosilene tunicoides, an endemic species to China, was cytologically studied for the first time. The morphology of the nuclei at resting stage was categorized to be simple chromocentre type. The morphology of mitofic-pmphase chromosomes was categorized to be the interstitial type.28 chromosomes were observed at the mitotic metaphase, and 14 bivalent chromosomes were observed at diakinesis. So, the basic chromosome number was confirmed to be x = 14. Psomzr~silene tunicoides is different from Silene rubicunda in the basic chromosome number and the morphology of the nuclei at resting stage and mitotic-prophase chromosomes, because Sgene rub/cund has the basic chromosome number of x= 10 and 12, and its nuclei at resting stage and mitotic-prophase chromosomes is sparsely diffuse type and continuous type respectivrly.     

Cytological study on the genus Syncalathium （Asteraceae-Lactuceae）, an endemic taxon to alpine scree of the Sino-Himalayas

Cytological characters of four species in Syncalathium （Asteraceae： Lactuceae）, a small genus with six identified species endemic to alpine scree of the Sino-Himalayan region, are surveyed in this report. Three species （Syncalathiumpilosum, Syncalathium chrysocephalum, and Syncalathium disciforme） are examined for the first time. Combined with our previous counts, five species have been cytologically investigated from the genus and the results indicated that all species are diploid with the basic somatic chromosome number of x=8. The karyotype asymmetry of Syncalathium souliei is 2A, distinct from the other four species of 1A, and the remaining species are divided into two subgroups with different karyotypes, consistent with their morphological features. The significance of the cytological evolution of Syncalathium is briefly discussed.     

向日葵单子叶和三子叶突变体的形态特征

Phyllotaxis and morphological characteristics of monocotyledonous and tricotyledonous mutants ( found during cultivation process) and dicotyledonous plants of Helianthus annuus Linn. were observed. The results show that numbers of monocotyledonous, dicotyledonous and tricotyledonous plants are 8, 339 and 3, respectively in 350 cultivated plants of H. annuus, accounting for 2. 3%, 96. 9% and 0. 9% of total individual number, respectively, and their corresponding phyllotaxis is alternate, opposite and whorled types, respectively. Monocotyledonous plant has the fewest leaf number, the most leaf layer number, and the largest flower diameter; tricotyledonous plant has the most leaf number, the fewest leaf layer number, and the smallest flower diameter. There is no obvious difference in plant height of individuals with different cotyledon types. It is suggested that cotyledon number of H. annuus is obviously correlated with phyllotaxis type.     

葡萄花药三倍体植株的倍性鉴定

用卡宝品红染色法检查格列那什二倍体葡萄(Vitis vinifera var. Cre nache)花药再生植株的染色体, 并用UNICHRO软件对其数目及长度进行了测量。结果表明,这些花药植株根尖中染色体组型为2n=3x=57的细胞平均占观察细胞总数的86.5%,来自不同花药的再生殖株均为三倍体。讨论了这些植株的可能来源。 Abstrart:The chromosome number in the root tip of triploid plants regenerated from anther culture of diploid Vitis vinifera var.Grenache were examined with Carbolfuchsin staining method and the length of chromosomes were measured with UNICHRO package.The results show that average pecentage of cells which have a karyotype for 2n=3x=57 in root tip of pollen plants were 86.5% in the total number of cells observed,the plants regenerated from different anthers are triploid.Their possible origin is discussed.     

Construction of a novel kind of expression plasmid by ho-mologous recombination in Saccharomyces cerevisiae

Saccharomyces cerevisiae is one of the most im- portant heterologous expression systems. The stability and copy number of expression plasmid in the host are the important factors to affect the expression levels of foreign genes[1―3]. pHC11 is a yeast episomal plasmid constructed by our laboratory[4]. It contains the entire sequence of the 2μ plasmid without disrupting its coding elements and other functional regions. The stability and copy number of pHC11 are relatively high. Making use of…     

家燕与金腰燕染色体的比较研究

本文对家燕和金腰燕的核型、C带和Ag-NORs带进行了比较研究。结果表明,两者的核型基本一致。核型公式:2n=80=2M+4ST+zMwSM+2M+2ST+2SM+8 T+2M+56mT/D。但两者在染色体的相对长度、W染色体大小、G带带型、A g-NORs的数目和分布均存在着差异。文中在家燕No.1、7、W染色体和金腰燕No.1、 6、7染色体的形态划分,金腰燕W染色体的确定及其染色体数目等方面,均与卞小庄、李庆伟的结果不同。 Abstract:A comparative study on karyotype and C-band and Ag-NORs of house swallow and red-rumped swallow has been made.The result shows that the karyotype of them are similar,and their karyotypical formulae is 2n=80=2M+4ST+zMwSM+2M+2ST+8T+2M+56mT/D.But they are different in the relative length of chromosomes,the size of W chromosome,C-band patterns and the number and distribution of Ag-NORs.The chromosomes,the size of W chromosome,C-band patterns and the number and distribution of Ag-NORs.THE result in this paper is different from that of Mr.Bian and Mr.Li in the types of No.1,7,W chromosomes of house swallow and No.1,6,7 chromosomes of red-rumped swallow and the determination of W chromosome and diploid number of red-rumped swallow.     

Global dynamics of a cholera model with age structures and multiple transmission modes

In this paper,we propose and analyze a cholera model.The model incorporates both direct transmission (person-to-person transmission) and indirect transmission (contaminated environment-to-person transmission: hyper-infectivity and lower-infcctivity).Moreover,we employ general nonlinear incidences and introduce infection age of infectious individuals and biological ages of pathogens in the environment.After considering the well-posedness of the system,we study the existence and local stability of steady states,which is determined by the basic reproduction number.To establish the attractivity of the infection steady state,we also get the uniform persistence and existence of compact global attractors.The main result is a threshold dynamics obtained by applying the Fluctuation Lemma and the approach of Lyapunov functionals.When the basic reproduction number is less than one,the infection-free steady state is globally asymptotically stable while when the basic reproduction number is larger than one,the infection steady state attracts each solution with nonzero infection force at some time point.The effect of multiple transmission modes on the disease dynamics is also discussed.     

Supplemental Cytogeographical Studies on the Scilla sinensis （Louriro） Merrill Complex in China

Seven hundred and fourteen individuals of the Scilla sinensis (Louriro) Merrill complex were sampled from 21 populations at 19 localities in 10 provinces and two cities of China and investigated cytologically in order to test its cytotype composition and cytogeographical variation still further. Five cytotypes were found (i.e. AA (2n = 16), BB (2n = 18), AABB (2n = 34), AAA (2n = 24), and AABB 9 (2n =43)). Until now, nine of the 12 cytotypes have been identified on the continent, which indicates that it is an important place for the cytotypic differentiation of the complex. The cytotype AABB 9 is a new record on the continent. AAA was recorded for the second time in this complex. The majority of populations are composed of only one cytotype (AA, BB, or AABB), whereas another four populations consist of more than two cytotypes involving AA, BB, AAA, AABB, and AABB 9. The distribution of BB covers the entire region south to Huai River, whereas AA populations are distributed in Taiwan, Fujian, Hong Kong, and Guangdong and are isolated from its major distribution. The appearance of AABB 9 is possibly evidence for the degeneration of the subglobular bulb type of AABB and the fact that AAA and AAAA exist in the interior border regions of the range of this complex probably suggests that drought is a major factor promoting plant polyploidization. In addition, the mean numbers of B chromosomes per individual, the percentage of individuals with the B chromosome in each population, and the correlation coefficients between the latter and their latitude/longitude were calculated. Generally speaking, the B chromosome number is higher in BB populations compared with AA populations and there is a prominent tendency that the B chromosome content in either AA or BB populations correlates with the latitude and longitude of the populations.     

Effect of Cambering on the Aerodynamic Performance of Heaving Airfoils

In the present work,a parametric numerical study is conducted in order to assess the effect of airfoil cambering on theaerodynamic performance of rigid heaving airfoils.The incompressible Navier-Stokes equations are solved in their velocity-pressureformulation using a second-order accurate in space and time finite-difference scheme.To tackle the problem ofmoving boundaries,the governing equations are solved on overlapping structured grids.The numerical simulations are performedat a Reynolds number of Re=1100 and at different values of Strouhal number and reduced frequency.The resultsobtained show that the airfoil cambering geometric parameter has a strong influence on the average lift coefficient,while it hasa smaller impact on the average thrust coefficient and propulsive efficiency of heaving airfoils.     

Cloning of Ln Gene Through Combined Approach of Map-based Cloning and Association Study in Soybean

Increasing yield is one of the most important goals in crop breeding.Soybean(Glycine max L.Merr.),one of the most economically important leguminous seed crops,provides the majority of plant proteins,and more than a quarter of the world’s food and animal feed(Graham and Vance,2003). The yield of soybean is finally determined by the number of seeds per unit area,which affected by many characters,such as height,branching number,photosynthesis,seed size,seed number.The number of seeds per pod is taken for one of the critical components that related to yield(You et al.,1995),and it has long been considered in soybean production(Takahashi,     

山东10种植物的核型分析

对山东１０ 种植物进行了核型分析。茴茴蒜（ Ｒａｎｕｎｃｕｌｕｓｃｈｉｎｅｎｓｉｓ Ｂｇｅ－） 染色体数目２ｎ ＝１６ , 核型公式Ｋ（２ｎ） ＝ ２ｘ ＝ １６ ＝ ２ Ｍ ＋ ２ｍ ＋ ２ｓｍ ＋ １０ｓｔ, “３Ａ”类型; 五脉地椒（ Ｔｈｙｍｕｓｑｕｉｎｑｕｅｃｏｓｔａｔｕｓ Ｃｅｌａｋ－） 染色体数目２ｎ＝ ２６ , 核型公式Ｋ （２ｎ） ＝ ２ｘ＝ ２６ ＝ ８ Ｍ ＋ １８ｍ , “１Ａ”类型; 蛇床（ Ｃｎｉｄｉｕｍ ｍｏｎｎｉｅｒｉ（Ｌ－） Ｃｕｓｓ－） 染色体数目２ｎ＝ ２０ , 核型公式Ｋ （２ｎ） ＝ ２ｘ＝ ２０ ＝ ２Ｍ＋ １６ｍ ＋ ２ｓｍ , “２Ｂ”类型; 波斯菊（ Ｃｏｓｍｏｓ ｂｉｐｉｎｎａｔｕｓ Ｃａｖ－） 染色体数目２ｎ ＝ ２４ , 核型公式Ｋ（２ｎ） ＝ ２ｘ ＝ ２４ ＝ １６ｍ ＋ ２ｍ （ｓａｔ） ＋ ６ｓｍ , “２Ａ”类型; 白车轴草（ Ｔｒｉｆｏｌｉｕｍ ｒｅｐｅｎｓ Ｌ－） 染色体数目２ｎ＝ ３２ , 核型公式Ｋ （２ｎ） ＝ ４ｘ ＝ ３２ ＝ ３２ｍ , “１Ａ”类型; 铁苋菜（ Ａｃａｌｙｐｈａ ａｕｓｔｒａｌｉｓ Ｌ－）染色体数目２ｎ ＝ ３２ , 核型公式Ｋ （２ｎ） ＝ ２ｘ＝ ３２ ＝ ３２ｍ , “１Ｂ”类型; 地构叶（ Ｓｐｅｒａｎｓｋｉａ ｔ?     

多花水仙(Narcissus tozetta L.)染色体基数x=10和X=11之间进化关系的研究

多花水仙的染色体基数有x=10和x=11两类。基数x=10组型有两种,一种是具6长、4短的典型不对称的二形染色体组型;另一种是具有4长、2中、4短(或5长、2中、3短)的非二形染色体组型。基数x=11则具有4长、2中、5短(或5长、2中、4短)的非二型或非典型二形的染色体组型。x=10的典型不对称的二形染色体组型是原始的组型。基数x=11是从原始的x=10、2n=20组型中的(第5、6号)染色体发生不等长易位后,增加了一对短小的中着丝粒染色体而形成的。另一个x=10、2n=20的非二型新组型,可能从x=11组型丢失了短小的中着丝粒染色体衍生而来,也可能从易位后的个体所产生的不含中着丝粒染色体的雌、雄n配子结合而得到。     

活血莲的核型分析

对活血莲的染色体数目及核型进行了研究,结果表明,活血莲的染色体数目为２ｎ＝６０,其核型公式为２ｎ＝２ｘ＝６０＝４６ｓｍ＋１２ｓｔ＋２ｍ。没有观察到带随体的染色体。     

活血莲的核型分析

对活血莲的染色体数目及核型进行了研究,结果表明;活血莲的染色体数目为2n=60,其核型公式为2n=2x=60=46sm+12st+2m,没有观察到带随体的染色体。     

角堇与大花三色堇染色体核型分析

以2份角堇与4份大花三色堇自交系为试验材料,采用染色体常规压片方法,观察和分析了它们的细胞染色体数目、相对长度、平均臂比等核型指标,以明确两种植物细胞学特点,为分类以及育种提供理论依据。结果表明:(1)2份角堇自交系染色体数目均为2n=2x=26,染色体基数为x=13,染色体核型公式分别为2n=2x=26=8m+12sm+6st、2n=2x=26=4m+16sm+6st,核型不对称系数为67.20%~70.10%,核型分类均属于3B。(2)4份大花三色堇自交系均为四倍体,其中2份(EYO-1-2-1-4、DSRFY-1-1-2)染色体数目为44,核型公式为2n=4x=44=4m+16sm+6st、2n=4x=44=16m+24sm+4st;2份(G10-1-3-1-4、XXL-YB-1-1-1-1)染色体数目为48,核型公式分别为2n=4x=48=8m+20sm+20st、2n=4x=48=4m+36sm+8st,核型不对称系数为66.74%~71.77%,核型分类属于2B、3B。     

三褶虾脊兰的核型分析

采用压片法研究了三褶虾脊兰[Calanthe triplicata(Willem.)Ames]的染色体数目和核型.结果表明:三褶虾脊兰的染色体数目2n=38,为二倍体,核型公式为2n=2x=38=28m 8sm 2st.主要由中部和近中部着丝点染色体组成.核型分类为2B型,比较对称.     

三种金花茶及其组培苗的核型比较

本文研究了东兴金花茶(Camellia tunghinensis Chang)、柠檬黄金花茶(Camellia limonia C. F. Liang et S. L. Mo)、淡黄金花茶(Camellia flavida Chang)及其组培苗的染色体数目及核型。东兴金花茶及组培苗的核型公式为2n=2x=30=22m(2SAT) 8sm;柠檬黄金花茶及组培苗为2n=2x=30=24m(2SAT) 6sm;淡黄金花茶及组培苗为2n=2x=30=24m(2SAT) 6sm;核型比较发现三种金花茶的组培苗与其野生植株的核型基本一致。表明以组培方法保存和繁殖金花茶是有价值的。     

开普芦荟和木立芦荟的染色体核型分析

对盆栽开普卢荟(Aloe ferox Miller)和木立卢荟(Aloe arborescens Miller)植物根尖细胞的染色体进行了观察分析。结果表明开普芦荟和木立芦荟的染色体数与已见报导的百合科(Liliaceae)中国芦荟(Alov vera var.chinensis)植物染色体数相同, 2n=14。染色体类型按Levan 方法分类, 没有近端部染色体和随体。开普芦荟和木立芦荟的染色体核型分析结果均为K(2n)=2x=4sm+10st。根据Stebbins 的核型分类标准, 开普芦荟的核型为"4C"型, 而木立芦荟的核型为"3C"型。两种芦荟染色体相对长度组成均为2n=14=6L+2M2+6S。根据核型研究, 可以确定百合科开普芦荟和木立芦荟的染色体基数为X=7。     

Karyotype Analysis of Hydrilla

The present paper reports the chromosome number and karyotype of the genus Hydrilla. H. verticillate was found to have 2n=16. The karyotype is 2n=16=6m+6sm+ 4st. No difference between the male and the female was found in the work. H. verticillata var. roxburghii Casp. has the somatic chromosome number 2n=24, and its karyotype is 2n= 3x=24=9m+9sm+6st. The variety may be a autotriploid. The karyotype of the genus isobviously bimodal, with No. 1-5 in the first group and 6-8 in the second group.     

Study on Chromosome Number and Karyotype of Ammopiptanthus mongolicus

This paper deals with chromosome number and karyotype of Ammopiptanthus mongolicus (Maxim.) Cheng f., whose karyotype formula is 2n = 18 = 4m+14sm(2SAT), and the basic number of the genus is x = 9.