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1.
C. Moran  D. D. Shaw 《Chromosoma》1977,63(2):181-204
The acridine grasshopper, Caledia captiva exists as two chromosomal races in south-east Queensland. One of these, the Moreton race inhabits the coastal region to the east of the Great Dividing Range. All chromosomes of the complement (2n=11II+XO/XX) have been involved in centromeric rearrangement, which transforms the acro- and telocentric chromosomes into submeta- and metacentric elements. The second, or Torresian race is widely distributed through southern Papua, Arnhem Land, Cape York Peninsula and down the east coast of Australia as far south as Brisbane. This race, which is characterised by a completely acro- and telocentric chromosome complement, approaches the Moreton race in south-east Queensland where the two races are separated by less than 1 km, along a front of at least 150 km. Evidence is presented to show that chromosome introgression is occurring across the contact zone and this takes place in one direction only, namely the Torresian chromosomes are infiltrating into the Moreton race but not reciprocally. Furthermore, the introgression of chromosomes across the zone is limited to certain members of the Torresian complement and even then these successful chromosomes show highly variable degrees of penetrance into the Moreton race. It is proposed that a tension zone exists between these two races which is maintained by the interaction of (a) ecological tolerance differences on either side of the zone and (b) by partial competitive exclusion due to the interracial differences in phenology. This case of parapatric association with limited hybridisation is unique in its clarity due to the marked differences in the appearance of the chromosome complements of these races which permits direct assessment of the behaviour of most members of the genome in hybrids and their derivatives.  相似文献   

2.
Paddy levees form networks of narrow linear habitats and play various roles in cultural landscapes. Traditional landscapes on the west side of Lake Biwa consist of paddy field terraces and both stone and soil levees that have been maintained by paddy field management using local resources. Paddy levees in this study site are principally classified into five different types. Our study points out how differences in paddy levee structure as well as in management practices influence the plant species. Seventeen paddy levee transects were split into four habitat types based on their species components by TWINSPAN. Spatial characteristics and physical structures of paddy levees depended on natural conditions and human activities. The species–area curves of each levee type showed a clear distinction: the soil, stone and abandoned curves were steep, while the concrete and consolidated ones were gentle. The vegetation on consolidated levees was utterly different from the vegetation on traditional levee types from the aspect of species richness and species components. Soil type levees contained various woody plant species and included more diverse and indigenous plant species than abandoned type levees.  相似文献   

3.
Competition in a natural system may be interspecific or intraspecific. In semiarid ecosystems, competition for resources between established neighboring grass species and newly recruited seedlings is very high. To examine the effects of grass species density, growing space and time of establishment on Eucalyptus victrix seedlings (interspecific competition), and the effect of density and growing space within E.victrix (intraspecific competition) we conducted an experiment under controlled conditions. We tested four hypotheses (i) E.victrix seedling growth is not affected by grass density; (ii) there is no difference in E.victrix survival and growth between early and later grass establishment; (iii) interspecific competition is not more intense than intraspecific competition in E.victrix; and (iv) growth of E.victrix seedlings is not dependent on available growing space. In a monoculture of E.victrix, seedling mortality was higher (10%) in large pots. In mixed culture pots, where E.victrix seedlings and grass seedlings were planted on the same day, E.victrix seedlings survived for up to 4weeks, but started to die after week five in the smallest pots. However, mortalities occurred in pots of all sizes when grass was established before E.victrix seedlings. Results also indicated that the resources necessary for the growth of individual E.victrix seedlings were more limiting under conditions of increased density of neighboring grass species rather than intraspecific competition. In particular, photosynthetic area of E.victrix seedlings was drastically reduced in mixed cultures. Although density, pot size and time of planting had impacts on E.victrix seedlings, the patterns of these impacts were variable.  相似文献   

4.
Summary Changes in the -butyrolactone and pantolactone contents in yeast cells and musts during fermentation and subsequent flor veil formation of Sherry wines were studied. Saccharomyces cerevisiae race cerevisiae, S. cerevisiae race bayanus and S. cerevisiae race capensis were used. During the alcoholic fermentation (first 31 days), -butyrolactone contents in musts and yeast cells were similar for the three yeast races tested. In this period, pantolactone was excreted to the must by bayanus and capensis races, and it was not detected in cerevisiae race cells. During flor veil formation (31 to 134 days), bayanus and capensis races yield higher -butyrolactone and pantolactone contents than cerevisiae race in the wines. In the final wines, pantolactone contents were always lower than those of -butyrolactone.  相似文献   

5.
Summary Recently, DNA fingerprints have been reported in a wide array of organisms. We used the M13 repeat probe on several genera and species in the angiosperm family Rosaceae. Four apple cultivars could be differentiated when any one of five restriction enzymes was used to analyze minisatellite DNA. Similarly, four individual trees of Prunus serotina (black cherry) exhibited different fingerprints with each of four enyzmes. A total of 14 Rubus (blackberries and raspberries) plants representing four species were investigated with two enzymes. Extensive inter-and intraspecific variation was found. However, some closely growing plants had identical fingerprints, probably due to their being derived through vegetative propagation.  相似文献   

6.
Summary The seasonal progression of phenophases in 21 shrub species of the Chilean matorral was analyzed. Five modules or basic units that are responsible for the aboveground architecture of the plants were characterized. These modules appear to be organized in seven different spatial arrangements. In drought-deciduous species a module type with an absolute short shoot with limited apical growth, leafy or spiny, predominated. In evergreen species long shoot and temporal leafy short shoot module types were more frequent. The spatial arrangement of morphologically different modules and the temporal sequence of their formation allow a dynamic interpretation of the modular architecture of the plants.  相似文献   

7.
Summary Animal census data from Lake Manyara National Park in northern Tanzania are presented. The data refer to large mammalian herbivores, that is individually heavier than twenty kg, of which the numbers were counted in nine different years between 1959 and 1984. The total biomass of these herbivores was comprised mainly of African buffalo and African elephant. Five functional groups of herbivores were distinguished (buffalo, elephant-as-grazer, elephant-as-browser, other grazers, and other browsers). The pressures of all these groups were constant over time with the exception of that by buffalo. Buffalo numbers increased since the last outbreak of rinderpest in 1959. There was no correlation between herbivore biomass and rainfall fluctuations. Individual species showed large fluctuations in their numbers but within the total herbivore assemblage the different species compensated the fluctuations of the other species. This resulted in an overall constancy of herbivore biomass, and, thus, the carrying capacity of the system has to be viewed on the level of all species combined and not on that of the individual species. This view is supported by the result that size of the stability index showed that the system of herbivore species was stable.  相似文献   

8.
Residual toxicities of registered and selected experimental pesticides used on citrus against Agistemus industani Gonzalez (Acari: Stigmaeidae) were compared. Pesticides considered highly toxic to A. industani were: abamectin 0.15 EC at 731ml/ha+FC 435-66 petroleum oil at 46.8l/ha, pyridaben 75WP at 469g/ha, ethion 4EC at 7.01l/ha+FC 435-66 petroleum oil at 46.8l/ha, propargite 6.55 EC at 3.51l/ha, chlorfenapyr 2SC at 1.46l/ha applied alone or in combination with FC 435-66 petroleum oil at 46.8l/ha, sulphur 80DF at 16.81kg/ha, dicofol 4EC at 7.01l/ha, fenbutatin oxide 50WP at 2.24kg/ha, benomyl 50WP at 2.24kg/ha, benomyl 50WP at 1.68kg/ha+ferbam 76 GF at 5.60kg/ha, ferbam 76GF at 11.21kg/ha, neem oil 90EC at 46.8l/ha, and copper hydroxide DF (40% metallic copper) at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha. Pesticides that were moderately to slightly toxic included: copper sulphate 98% at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha, fenbuconazole 2F at 280ml/ha+FC 435-66 petroleum oil at 46.8l/ha, FC 435-66 petroleum oil applied alone at 46.8l/ha or 23.4l/ha, and diflubenzuron 25WP at 1.40kg/ha. Pesticides that were non-toxic included: fenbuconazole 2F at 585ml/ha, malathion 57EC at 5.85l/ha, FC 435-66 petroleum oil at 46.8l/ha, carbaryl 80S at 3.36kg/ha, chlorpyrifos 4EC at 4.68l/ha, and formetanate 92SP at 1.12kg/ha. Understanding the toxic effects of field weathered pesticides against key predacious mite species is important for effective IPM. The results of this study provide a comparison of direct and indirect toxic effects of various pesticides to A. industani under field conditions.  相似文献   

9.
The main carotenoid of Flavobacterium strain R1560 has been identified as (3R,3R)-zeaxanthin. Also present were small amounts of 15-cis-phytoene, phytofluene, -carotene (7,8,7,8-tetrahydro-, -carotene plus 7,8,11,12-tetrahydro-, -carotene), neurosporene, lycopene, -zeacarotene, -carotene, -carotene, -cryptoxanthin, rubixanthin, 3-hydroxy--zeacarotene and several apo-carotenals. Zeaxanthin production was inhibited by nicotine (10 mM), and lycopene and rubixanthin accumulated. The biosynthesis of zeaxanthin is discussed in terms of pathways and also of half-molecule reaction sequences. The presence of zeaxanthin may be a characteristic of a group of Flavobacterium species, and may thus be useful in the taxonomic classification of these organisms.  相似文献   

10.
Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.  相似文献   

11.
Petitpierre E  Garnería I 《Genetica》2003,119(2):193-199
The chromosomes of ten species of Cyrtonus and the genome sizes of six are surveyed. Among the total of 15 chromosomally studied species, 11 have 2n=28 chromosomes and a 13+Xyp male meioformula, three have 2n=40 and 19+Xyp and one 2n=46 and 22+Xyp. All but one species with 28 chromosomes show only metacentric or submetacentric chromosomes, whereas the species with 40 and 46 chromosomes display some telocentrics or subtelocentrics, that are probably derived from the former by centric fissions. However, since the number of major chromosome arms is strikingly higher in these latter species (NF=70 and 78) than in the 28-chromosome species (mostly NF=56), other chromosomal rearrangements such as pericentric inversions or heterochromatin accretions could also be involved. The genome sizes display a narrow range, from 1C=0.6–1.22pg, and they are not significantly correlated with the chromosome numbers. Some possible factors implied in the rough chromosomal evolution of Cyrtonus are discussed in relation to a few other genera of the subfamily Chrysomelinae.  相似文献   

12.
Summary Of the 20 species ofPythium reported from India, not more than seven assume parasitic role inciting mainly diseases in seed bed and sometimes in the fields such as damping-off, seedling blights and foot rots. The paper gives a brief account of the taxonomy of the Indian species and methods of controlling the diseases incited by them.  相似文献   

13.
Success of seed development following sexual crosses is primarily dependent on proper endosperm function and development. The failure to produce triploids, or triploid block in 4x×2x crosses served as the impetus for numerous studies of embryo and endosperm to attempt to explain cross failure. Early explanations were based upon a concept of a 232 ploidy balance between maternal tissue, endosperm, and embryo. Subsequent studies done with maize demonstrated that normal endosperm development in intraspecific maize crosses is dependent solely on having a 21 maternal to paternal genome dosage in the endosperm. These results have been modified and extended to solanaceous species in the form of an endosperm dosage system in which empirically determined factors must bear the same 21 relationship for crosses to succeed. Crossing behavior of these species suggest that the system is polygenically controlled and regulates both interspecific and intraspecific crosses. Endosperm dosage systems explain many aspects of species evolution, but the system appears to have originated as an ancient means of ensuring diploid fidelity.  相似文献   

14.
The carbohydrate-binding specificity ofPseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal3Gal- or Gal4Gal-structures.Abbreviations PA-I Pseudomonas aeruginosa lectin I - Cer ceramide - lactosylceramide Gal4GlcCer - iso globotriaosylcerami Gal3Gal4GlcCer - globotriaosylceramide Gal4Gal4GlcCer - globoside or globotetraosylceramide GalNAc3Gal4Gal4GlcCer - Forssman glycolipid GalNAc3GalNAc3Gal4Gal4GlcCer - P1 glycolipid Gal4Gal4GlcNAc3Gal4GlcCer - lactoneotetraosylceramide Gal4GlcNAc3Gal4GlcCer - B5 glycolipid Gal3Gal4GlcNAc3Gal4GlcCer - gangliotetraosylceramide Gal3GalNAc4Gal4GlcCer - GM1 Gal3GalNAc4(NeuAc3)Gal4GlcCer - RBC red blood cells - BSA bovine serum albumin - PBS phosphate-buffered saline - SDS sodium dodecyl sulfate - TLC thin-layer chromatography - HPLC high pressure liquid chromatography - MS mass spectrometry - FAB fast-atom bombardment - EI electron impact  相似文献   

15.
A scheme for the reaction of hemoglobin with ligands is described, which postulates the functional heterogeneity of the chains, considers all possible combinations of the distribution of the ligand on the four chains of hemoglobin, and does not require simplifying assumptions about the hemoglobin reactivity. Ten tetrameric species are considered, together with 16 reactions between these species, each with an on and an off rate constant. The dissociation of hemoglobin tetramers into dimers is also considered, with four on and four off rate constants for the reactions between dimers, and ten equilibrium constants for the reactions between tetramers and dimers. Moreover, some side reactions, such as the trapping of ligands by a hemoglobin competitor, are included. A FORTRAN program, suitable for microcomputers, is described for handling this scheme, with some examples showing its advantages.  相似文献   

16.
H. -U. Koop  O. Kiermayer 《Protoplasma》1980,102(1-2):147-166
Summary Protoplasmic Streaming inAcetabularia mediteranea has been studied by microcinematography in 1. germinating zygotes, 2. germlings before the differentiation of rhizoids and apices, 3. young cells with rhizoids and apices, 4. vegetative cells-several centimeters in length, 5. cells with a maximum sized cap, containing secondary nuclei, and 6. cells after cyst formation. Intracellular transport is found to occur at a network-system of thin filaments and at a different system of headed streaming bands. At the network of filaments chloroplasts are found to move at a velocity of 1–2 m/sec. Headed streaming bands move along the filaments and may lead without interruption from the rhizoid to the apex of the cell andvice versa. The front zone of the streaming bands is occupied by a leading cytoplasmic head-structure. Small vesicles, polyphosphate granula and secondary nuclei are the predominant moving structures in headed streaming bands. The velocity of these particles is found to be 3–11 m/sec. The filament system is found during all developmental stages. Headed streaming bands are undetectable in germinating zygotes and develop from small cytoplasmic droplets in germlings to broad heavily loaded bands in the huge vegetative cell.Transport of secondary nuclei by headed streaming bands is not observed during mitotic divisions and after cyst formation, though moving bands are still present for several weeks after cyst formation.  相似文献   

17.
We have developed a new method for the large scale preparation of pyridylaminated (PA-) oligosaccharides from glycoproteins. Phenol/chloroform extration was adapted for the removal of protein and excess 2-aminopyridine, improving the efficiency of preparation. From a 2.5 g sample of human apo-transferrin, 25–30 mol of agalacto biantennary PA-oligosaccharide could be obtained. By increasing the concentration of PA-oligosaccharide substrate, we were able to detect a very low level ofN-acetylglucosaminlytransferase IV activity in CHO cell extracts.Abbreviations PA 2-aminopyridine - SDS sodium dodecyl sulfate - GlcNAc N-acetylglucosamine - GnT N-acetylglucosaminyltransferase - Gn,Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-tri-PA GlcNAc1-2(GlcNAc1-4)Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-trí-PA GlcNAc1-2Man1-3({GlcNAc1-2(GlcNAc1-6)Man1-6})Man1-4GlcNac1-4GlcNAc-2-aminopyridine - Gn,(Gn),Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-4)(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine  相似文献   

18.
Résumé En l'absence de son propre couvain,Solenopsis fugax a élevé des larves deLeptothorax nylanderi, à la température de 22°C. Les ouvrières deSolenopsis détruisirent une partie de ces larves mais nourrirent celles qu'elles épargnèrent; ces dernières grossirent lentement pendant cinq à six mois, sans atteindre le stade prénymphe. Lorsque les ouvrières deS. fugax et les larves deL. nylanderi furent soumises ensemble à un hivernage préalable, elles donnèrent les mêmes résultats que sans hivernage. La présence d'une jeune reine deSolenopsis fut défavorable aux larves deLeptothorax.Inversement,L. nylanderi fut capable d'élever, à la température de 22°C, des larves deS. fugax et de les amener jusqu'au stade adulte. En présence de leurs propres larves, les ouvrières deL. nylanderi détruisirent tapidement toutes les larves deS. fugax introduites dans leur nid. D'autre part, un jeune couvain deLeptothorax remplaçait plus ou moins rapidement les larves deLeptothorax enlevées au préalable; sa présence était alors défavorable au développement des larves deSolenopsis. Un hivernage en début d'expérience fut plutôt favorable auxS. fugax, de même que la présence d'une reine féconde deLeptothorax. LesSolenopsis ainsi obtenus n'ont pas vécu plus de sept semaines. Ils étaient tous de caste ouvrière et de taille très petite.
Summary When its own eggs and larvae missed,Solenopsis fugax bred larvae ofLeptothorax nylanderi, at a temperature of 22°C. TheSolenopsis workers killed some of this larvae and fed the others; these slowly grew bigger during five or six months but never reached the pre-pupa stage. The result was the same if the workers ofS. fugax and the larvae ofL. nylanderi overwintered together or not at all. A youngSolenopsis queen being there was noxious to the larvae ofLeptothorax.On the contrary,L. nylanderi has been able to breed larvae ofS. fugax up to the imago stage, at a temperature of 22°C. When its own larvae were in the nest, together with larvae ofS. fugax, the workers ofL. nylanderi killed the larvae ofS. fugax. On the other hand, new eggs and young larvae ofLeptothorax had to replace, more or less quickly, the larvae which had been taken away, and that was noxious to the growth ofSolenopsis larvae. An overwintering at the beginning of the experiment was rather favourable toS. fugax as was the presence of a fecundLeptothorax queen. TheSolenopsis thus obtained lived no longer than seven weeks. They all were workers and very small.

S. Fugax L. Nylanderi 22° . Leptothorax , , , , . . S. Fugax Leptothorax.,L. Nylanderi 22° S. Fugax . L. Nylanderi ( )Leptothorax ; S. Fugax Solenopsis, Leptothorax. S. Fugax . .
  相似文献   

19.
Polyclonal antibodies to mouse - and /-caseins were raised in rabbits. These antibodies display tissue- and species specificity as shown by immunoblotting. Immunohistochemical analyses demonstrate that both - and /-caseins were synthesized and secreted from virtually all lactating mammary epithelial cells, in a pattern very similar to that of the mouse -lactalbumin. Residual amounts of caseins were located also in the apical surface of epithelial cells surrounding the ducal lumen of virgin mammary gland sections. In contrast to the significant level of -casein in the milk, the amount of this protein compared to - or -caseins was extremely low in medium conditioned for 24 h by mammary explants of mid-pregnant mice immediately after explantation or after 4 days.  相似文献   

20.
Karl Mägdefrau 《Plant Ecology》1968,16(5-6):285-297
Zusammenfassung Im Gegensatz zu dem morphologischen Begriff Wuchsform wird der ökologische Begriff Lebensform definiert als der Habitus einer Pflanze in Einklang mit ihren Lebensbedingungen. Es werden 10 Lebensformen der Laubmoose unterschieden, ihr Anteil an verschiedenen Pflanzenformationen und Moosgesellschaften dargelegt und ihre Abhängigkeit von den ökologischen Bedingungen erörtert.
Summary In opposition to the morphological term growth-form the ecological term life-form is defined as the organization of a plant in correspondence with its life conditions. Ten life-forms of mosses are discerned, their part within various plant-formations and moss-associations is explained, and their dependence on ecological conditions is discussed.


Herrn Prof. Dr. Carl Troll in herzlicher Verehrung zum 70. Geburtstag gewidmet.  相似文献   

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