Study on the vesicular-arbuscular mycorrhiza of three cultivars of potato (Solanum tuberosum L.)

Summary The establishment and development of vesicular-arbuscular mycorrhizal (VAM) fungi were studied in three cultivars of potato, which differed in susceptibility to Late blight, in a field experiment on a lateritic sandy-loam during two growing seasons (1980 and 1981). The cultivars SSC 1174 (highly resistant) and Kufri Jyoti (resistant) showed an earlier establishment and more rapid development of VAM fungi than up-to-date (highly susceptible). The first mycorrhizal infection in both SSC 1174 and Kufri Jyoti was observed after 12 days in 1980 and 8 days in 1981, whereas in up-to-date it was observed after 19 and 12 days respectively. The mycorrhizal infection increased with the age of the plants in all the three cultivars.     

Conflicting priorities in site management in England

There are two main designations of protected areas in the UK-nature reserves, of various kinds, and special nature conservation areas, known as Sites of Special Scientific Interest. General approaches to choices of priorities and the resolution of conflict in the management of these areas are described and difficulties identified. Similar problems arise when considering the wider role of protected areas in national nature conservation policies, e.g. biodiversity targets and European Habitats and Species Directive objectives. Because choices and priorities stem from underlying values, the public must be involved in the identification of objectives for both protected areas and the rest of the land surface. The Natural Areas programme being developed by English Nature provides a mechanism whereby people may be involved in characterising the wildlife of their area and in identifying targets for its maintenance and enhancement. The use of land and the management practices associated with it are the major factors influencing the nature conservation value of protected areas and their wider context.English Nature (the Nature Conservancy Council for England) is the statutory advisor to the government on nature conservation in England and promotes the conservation of England's wildlife and natural features.     

An alphoid DNA sequence conserved in all human and great ape chromosomes: evidence for ancient centromeric sequences at human chromosomal regions 2q21 and 9q13

Using vector-CENP-B box polymerase chain reaction (PCR) we isolated and cloned from a human chromosome 21-specific plasmid library, a 1 kb DNA sequence, named pH21. In in situ hybridization experiments, pH21 hybridized, under high stringency conditions, to the centromeric region of all the human, chimpanzee, gorilla and orangutan chromosomes. On human chromosomes pH21 also identified non-centromeric sequences at 2q21 (locus D2F33S1) and 9q13 (locus D9F33S2). The possible derivation of these sequences from ancestral centromeres is discussed. Sequence analysis confirmed the alphoid nature of the whole pH21 insert.GenBank accession number, M64321     

Geometry of the dry-state oligomerization of 2′,3′-cyclic phosphates

Summary Evaporation of a solution of thymidine plus either theexo or theendo diastereomer of uridine cyclic 2,3-O, O-phosphorothioate (U > p(S) in 1,2-diaminoethane hydrochloride buffer gave the 2,5 and 3,5 isomers of (P-thio) uridylylthymidine (Up(S)dT) in a ratio of 1:2 with a combined yield of about 20%. These isomers were re-converted to U > p(S) and dT by a reaction that is known to proceed by an in-line mechanism. Both the 2,5 and 3,5 isomers gave as product the same diastereomer of U > p(S) that had been used originally in their formation. These dry-state prebiotic reactions (Verlander, Lohrmann, and Orgel 1973) are thus shown to be stereospecific, and both the 2,5 and 3,5 internucleotide bonds are formed by an in-line mechanism.Abbreviations DAE 1,2-diaminoethane - HPLC high pressure liquid chromatography - RNase bovine pancreatic ribonuclease A, EC 3.1.4.22 - TEAB triethylammonium bicarbonate - tris tris(hydroxymethyl)aminomethane - UMP(S) uridine monophosphorothioate - U > p uridine cyclic 2,3-phosphate - U > p(S) uridine cyclic 2,3-O, O-phosphorothioate - Up(S)dT (P-thio)uridylylthymidine - U2p(R_p-S)5dT (P-thio)uridylylthymidine with theR configuration at phosphorous, and a 2,5 internucleotide linkage     

Geographische Herkunft und Anpassung beim Apfel

Zusammenfassung In den Jahren 1961 und 1962 wurden Untersuchungen mit Hilfe der Exosmose-Methode durchgeführt, um sich über die Frostresistenz von nahezu 100 Apfelsorten zu orientieren. Die Versuchsergebnisse (ausgedrückt in RLF-Werten, d. h. als Proportion des elektrolytischen Widerstandes zwischen den Kontrollen und den kältebehandelten Pflanzenteilen) zeigen gute Übereinstimmung mit den Resultaten anderer Härtebeurteilungsmethoden, z. B. mit den Gefrierversuchen in Gefrierkammern und mit den amerikanischen, deutschen und schweidischen Freilandbeobachtungen. Die berechneten Korrelationskoeffizienten gaben Werte von r=>+0,750 mit einer statistischen Sicherheit von P=<0,001. Es gibt jedoch Sorten, welche sich unter den verschiedenen Versuchsbedingungen nicht gleichartig verhielten. In diese Gruppe gehören die Sorten Goldparmäne, James Grieve, Lanes Prince Albert, Schöner aus Nordhausen, Slava Petersburga und Transparente de Croncels. Der Zusammenhang zwischen der geographischen Herkunft und der Frostresistenz ist augenfällig. Die durchschnittlichen RLF-Werte der frostempfindlichen oder sehr frostempfindlichen französischen Sorten liegen bei ungefähr 150, die der finnischen und baltischen frostharten Sorten dagegen unter 110. Die Rangordnung der verschiedenen Klimagebiete erfolgte entsprechend der geographischen Lage. Es gab Sorten, die der allgemeinen Tendenz nicht folgten und sich abweichend verhielten. Hierzu gehören: Transparente de Croncels, (Frankreich), Wealthy (USA), Cox Pomona und Ribston (Großbritannien). Über eine wesentlich schlechtere Resistenz, als auf Grund des Ursprungsgebietes zu erwarten war, verfügt Ontario (Kanada).     

Microspore cultures as donor tissue for the initiation of embryogenic cell suspensions in barley

We have initiated embryogenic cell suspension cultures of barley (Hordeum vulgare L.) Igri from isolated microspore cultures. Data were obtained on the time required for establishment, frequency of establishment, i.e. number of calluses out of the total number of initiations giving rise to suspensions, and embryogenic capacity of the suspension cultures. For comparison, establishment of embryogenic cell suspensions from callus derived from immature zygotic embryos of Igri, Dissa and Golden Promise was also carried out. The results revealed that embryogenic suspension cultures were established in half the time and with a seven-fold higher frequency from microspore cultures than from zygotic embryo-derived calluses. The suspension cultures were still capable of embryo formation after two years. However, only albino plantlets were regenerated. For comparison, long term callus cultures derived from microspores, anthers and zygotic embryos were established. From the anther and zygotic embryo-derived callus cultures green plants were continuously regenerated, whereas the microspore-derived callus cultures lost this ability after the second subculture.     

Covariation of sexual dichromatism and plumage colours in lekking and non-lekking birds: A comparative analysis

The extreme polygyny expressed by male lekking birds leads to the expectation that sexual dimorphism should be greater in lekkers than related non-lekkers. However, evidence for this association is weak, and many lekkers are actually monomorphic in size and plumage. To better understand the kinds of plumages associated with lekking, I characterized plumage variation for combinations of sexual dichromatism and colourfulness-and-conspicuousness (COCO) among lekking and related non-lekking birds. Compared in this way, the plumages of lekkers and non-lekkers differ dramatically for both sexes. Correlations between sexual dichromatism and COCO for phylogenetically independent contrasts are significant for male lekkers (positive) and female non-lekkers (negative), but not for female lekkers or male non-lekkers. Moreover, the total number of character–state combinations, and multivariate measures of variability, are greater in non-lekkers than lekkers.The characteristic plumages of lekkers (duller monochromatic, brighter dichromatic and intermediate between these extremes) comprise just a subset of those observed among non-lekkers, and exclude extremely dull dichromatic and extremely bright monochromatic plumages. I suggest that predation, and foraging behaviours compatible with lekking, may restrict plumage variation among lekkers. Thus ecological rather than overt sexual characteristics may explain monomorphism in birds under intense mate competition, as well as the paradox of strong female mate preferences on leks, where males appear to contribute only sperm to female reproductive efforts.     

α-and β-Glycosidases in maize roots

Four glycosidases were analyzed in 10 mm apical segments prepared from growing roots (15 mm) of Zea mays L. The pH optima were found to be 5.8 for -glucosidase, 4.4 for -galactosidase, 6.4 for -glucosidase and 6.0 for -galactosidase. The -glucosidase showed 4-fold higher activity than the -galactosidase. The distribution of the -glucosidase activity was signifcantly different from that of the -galactosidase, -glucosidase and -galactosidase.Abbreviations -Glu -glucosidase - -Gal -galactosidase - -Glu -glucosidase - -Gal -galactosidase     

Uptake of Zn++ and aflatoxin from perlite and liquid culture by Zea mays seedlings

The present paper reports our attempts to determine whether the inclusion of 0.0014 mM Zn⁺⁺ within a hydroponic culture medium affects the ability of 12-day-old Zea mays, cv. SS-522 to take-up [³H]-aflatoxin B₁. Data from the corollary experiment, i.e., whether inclusion of aflatoxin affects the ability of Zea mays, cvs. Truckers White, X-Sweet and Merit to take-up ⁶⁵ZnCl₂ are presented also. This report is a preliminary to one regarding an in-progress analysis of whether pollutant levels of Zn⁺⁺ affect aflatoxin uptake and distribution. In the absence of irrigating seedlings, which were grown in Perlite containing ⁶⁵ZnCl₂, with a solution containing mixed aflatoxins, the stem contained the greatest amount of label with root plus seed the next highest and the leaf the least for each of the cvs. In contrast, when the seedlings were irrigated with a solution containing mixed aflatoxins, the root plus seed contained either an amount nearly identical to (cv. Truckers White) or in excess of that within the stem (cvs. X-Sweet and Merit). Calculation of the percentages of aflatoxin-induced diminutions in leaf, stem and root label suggested that the aflatoxins interfered with the translocation of ⁶⁵ZnCl₂ from the root to the stem and leaf, at least for cvs X-Sweet and Merit. When 0.0014mM Zn⁺⁺ as ZnSO₄ was added to an incubation medium in which 12-day-old seedlings were suspended and plant growth assessed over 72 hours, a 15% increase (significant at 0.05 level) in seedling height over that of Zn⁺⁺-deficient plants was observed. No differences in [³H]-aflatoxin B₁ uptake were noted between those seedlings which were grown in either Zn⁺⁺-containing or lacking media. Less than one % of the[³H]-aflatoxin B₁ which was taken-up was recovered within chloroform extracts of the seedlings. The distributions of radioactivity from [³H]-aflatoxin B₁ for leaf, stem, seed and root were 0, 57, 26 and 19% and 0, 26, 58 and 18% for Zn⁺⁺-containing and -lacking media, respectively.     

The level of free amino acids in erythrocytes of different breeds of hen

Summary The content of free amino acids was determined in erythrocytes of adult Leghorn (Lg, White Rock (WR) and Cornish (Cr) hens, bred under identical conditions. The concentration of total amino acids was twice as high in the erythrocytes as in plasma, amounting to 396 m/100 ml, 424 m/100 ml and 475m/100 ml in White Rock, Cornish and Leghorn hens, respectively.Significant differences were found in the ratio of basic amino acids to acidic amino acids. These values were 0.76, 1.75 and 3.19 in White Rick, Leghorn and Cornish hens, respectively; in the plasma of all 3 breeds the ratio was 1. Statistically significant interbreed differences were expressed more distinctly in erythrocyte than in plasma amino acid concentrations. For absolute concentrations the differences were significant in the case of 9 amino acids.     

Degradation of alpha, beta, gamma and delta-hexachlorocyclohexanes by Sphingomonas paucimobilis

Sphingomonas paucimobilis degrades aerobically , , and -hexachlorocyclohexane. With -HCH, complete degradation occurred after 3 days but with and , and with -HCH, 98 and 56 % degradation occurred after 12 and 8 days of incubation, respectively. Pentachlorocyclohexene was formed as the primary metabolite during the degradation of all the HCH isomers. © Rapid Science Ltd. 1998     

Puromycin enhances 20-hydroxyecdysone-induced protein synthesis in wing discs of Drosophila melanogaster

The effect of cycloheximide and puromycin on 20-hydroxyecdysone-induced protein synthesis in wing discs of Drosophila melanogaster has been studied by one-dimensional and two-dimensional SDS polyacrylamide electrophoresis. It is found that puromycin, but not cycloheximide, when applied simultaneously with the hormone enhanced the hormone-induced synthesis of the early and late proteins. However, when puromycin was applied after hormone treatment, only the late proteins were induced. The possible implication of these observations is discussed.     

Ecological theories and Dutch nature conservation

This paper aims to achieve insight into various ecological theories in the Netherlands which have different, and sometimes opposing, views on the conservation of nature. Interviews, publications and archival research brought to light four separate theories: vitalistic/holistic, dynamic, cybernetic and chaos. Diversity is reached through stability according to vitalistic/holistic and cybernetic theories, but through change and instablility according to the dynamic and chaos theories. These two groups are working apart, and continue to have their own ideas. Prediction of the future is only possible with the vitalistic/holistic and cybernetic theories. Ecologists who adhere to these theories feel responsible and able in different ways to change ecological nature towards desirable end goals. The other two theories, dynamic and chaos, appear to be less activist.     

Stimulation of proliferation and immunoglobulin production of human-human hybridoma by various types of caseins and their protease digests

We have studied the effect of such milk proteins as caseins, lactalbumin, and lactoglobulin, on proliferation and immunoglobulin production of human-human hybridoma HB4C5 cells. It was found that -, -, and -caseins stimulated both proliferation and IgM product ion of human-human hybridoma HB4C5 cells, while the activities of -lactalbumin and -lactoglobulin were negligible. To localize the active sites of these caseins, effect of protease treatments on the activities were examined. When caseins were digested with trypsin, casein digests stimulated proliferation of the hybridoma, but not their IgM production. When -casein was digested with chymosin and fractionated top--casein and glycomacropeptide, both fragments stimulated proliferation of the cells, but onlyp--casein fragment stimulated IgM production. These results indicate that -casein has at least two proliferation stimulating sites and an IgM production stimulating site in thep--casein region.     

Genotypic stability analysis of yield and related agronomic characters in wheat-Agropyron derivatives under varying watering regimes

Summary Genotypic stability of grain yield and yield related traits was estimated for the 8 wheat-Agropyron derivatives, 441, 442, Vostock, PPG 56, PPG 56SS, 449, 450 and 441SS, together with two spring wheat controls, Drabant and Sv 01382, grown under varying watering regimes for two years. Differences among environments, genotypes and their interactions were highly significant for all traits. The genotypes X environments linear response were significant for number of spikelets per main spike, grain number per main spike and single grain weight. No significant linear responses were detected for grain yield or the rest of yield related traits. Deviations from linear responses were highly significant for all traits under study. Grain yield stability was not associated with the stability of yield components. PPG 56SS was identified as the stable variety with the highest mean grain yield per plant under the severe stress environment. Mean grain yields in the severe stress environment were correlated with the genotypic stability parameter . The severe stress environment was recognized as the optimum test environment. The study revealed a shift in the association between grain yield per plant and its components under the varying environments.     

Localization of a gene for human α-galactosidase B (=N-Acetyl-α-D-Galactosaminidase) on chromosome 22

Summary The localization of the structural gene for human -galactosidase B (=N-acetyl--galactosaminidase) was investigated by means of man-Chinese hamster and man-mouse somatic cell hybrids. The hybrid clones were analyzed for chromosomes and for a large number of known enzyme markers. The lysates of the hybrid cells were treated with Sepharose-coupled antihuman -galactosidase B and the activity of the adsorbed enzyme was measured on the Sepharose beads as N-acetyl--galactosominidase. The results show that the structural gene for human -galactosidase B is situated on chromosome 22, and that there is no structural relationship between human -galactosidase A and human -galactosidase B.     

Towards a functional classification of ectomycorrhizal fungi

Ectomycorrhizal (ECM) fungi have previously been divided into two groups (early-stage and latestage) based on their position in ectomycorrhizal succession. This classification has a number of limitations, particularly in the lack of precision in the terminology adopted and its general applicability. Many species cannot be easily assigned to either stage, and the behaviour of some species is modified by environmental conditions. In addition, a number of different mechanisms of ECM succession have been proposed, including the influence of organic matter and root exudates. In this paper, it is suggested that the phenomenon of ECM succession can be explained simply by the relative ability of different fungi to colonize and spread from different sources of inoculum. Epidemiological characteristics, such as the ability to produce mycelial strands or to spread on root systems by secondary infection, may therefore provide a more appropriate basis for a functional classification of ECM fungi. The functionally important characteristics of ECM fungi are discussed.     

Localization of α1,2,3-subunit isoforms of Na,K-ATPase in cultured neonatal and adult rat myocardium: The immunofluorescence and immunocytochemical study

By indirect immunofluorescence and preembedding peroxidase-diaminobenzidine technique the localization of polyclonal and monoclonal antibodies against 1, 2 and 3 isoforms of the Na,K-ATPase were studied in rat myocardium.The 1-subunit was identified predominantly on sarcolemma of cultured myocytes, neonatal, as well as adult cardiocytes. The 2 signal was localized around nuclei of cultured cardiocytes, very weak signals were seen in neonatal and more intense signal, were dispersed throughout the adult myocytes. The 3-subunit immunoreactivity was weak and localized in cell processes connecting individual cultured cells, on sarcolemma and intercalated discs of neonatal cells and very weak in adult working myocytes. Cytochemically demonstrated ouabain resistant Na,K-ATPase localized in junctional sarcoplasmic reticulum may represent 1 isoenzyme which is directly involved in modulation of action potential fluxes.     

Sulfur and its Doppelgänger

The case is presented for the universal adoption of the f spelling of the element sulfur and of all other names containing the sulf- root. This requires the overdue implementation of the IUPAC ruling that sulfur is the only acceptable English spelling for this element, its compounds, and derivative words.     

Heterogeneity of the α-globin gene defects in German α-thalassemia affected families

Summary Analysis of -thalassemia syndromes in several German families revealed DNA deletion as well as nondeletion forms as the molecular basis for the defects. Thus, the -thalassemia haplotype was identified as the (–)^3.7 rightward deletion form, and the region of the putative recombination process generating such a deletion was further characterized. In addition three different ° haplotypes, (--)^MED, (--)^>26, and ()^T, could be detected using -and -globin gene-specific probes.