(2E,4Z )-Decadienoic acid and (2E,4Z,7Z )-decatrienoic acid,two herbicidal metabolites from Streptomyces viridochromogenes Tü 6105     

Armin Maier  Johannes Müller  Peter Schneider  Hans-Peter Fiedler  Ingrid Groth  Francis S K Tayman  Friedrich Teltschik  Christian Günther  Gerhard Bringmann 《Pest management science》1999,55(7):733-739

Two fatty acids, (2E,4Z)-decadienoic acid and (2E,4Z,7Z)-decatrienoic acid, the latter being described for the first time as a natural product, were detected in the culture filtrate of Streptomyces viridochromogenes Tü 6105 by HPLC-diode array screening, purified by chromatographic methods and structurally elucidated by NMR techniques. Both metabolites show strong herbicidal activity against Lemna minor and Lepidium sativum. The herbicidal activities of the isolated compounds were compared with those of similar fatty acids and derivatives. © 1999 Society of Chemical Industry  相似文献   

Untersuchungen über den Einfluß der Mikronährstoffe Eisen und Mangan auf den Stickstoff-Stoffwechsel landwirtschaftlicher Kulturpflanzen: 2. Mitteilung: Untersuchungen über die Wirkung des Mangans auf die Nitratreduktion und den Gehalt an freien Aminosäuren in jungen Buschbohnenpflanzen     

Hans-Peter Vielemeyer  Friedrich Fischer  Werner Bergmann 《Archives of Agronomy and Soil Science》2013,59(4):393-404

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Enantioselective catalysis for agrochemicals: synthetic routes to (S)-metolachlor, (R)-metalaxyl and (αS,3R)-clozylacon     

Felix Spindler  Benoit Pugin  Hanspeter Buser  Hans-Peter Jalett  Ulrich Pittelkow  Hans-Ulrich Blaser 《Pest management science》1998,54(3):302-304

The application of enantioselective catalytic methods for the technical preparation of chiral agrochemicals is illustrated for three active ingredients of the acylanilide type. The key step for the technical synthesis of the herbicide (S)-metolachlor is the enantioselective hydrogenation of an imine intermediate using a novel iridium ferrocenyldiphosphine catalyst with an unprecedented high activity and 80% ee. (R)-metalaxyl and (αS,3R)-clozylacon were synthesized via the enantioselective hydrogenation of corre-sponding enamide precursors with Rh and Ru/binap catalysts with >95% and 99% enantiomeric purity, respectively. © 1998 Society of Chemical Industry  相似文献   

Is heterosis an artefact governed by the choice of scale?     

Barbara Keller  Hans-Peter Piepho 《Euphytica》2005,145(1-2):113-121

When estimating heterosis it is often necessary to transform either the data or, within the context of generalized linear models, the linear predictor, to satisfy certain assumptions. In this note it will be argued that the amount of heterosis is scale-dependent varying with the kind of transformation. The same applies for the examination of dominance in quantitative genetics. We exemplify the varying heterotic effect with phenotypic data of maize roots. Either a data transformation or a generalized linear mixed model with appropriately chosen link function is applied to the data. It is concluded that care should be exercised when transforming data in phenotypic as well as quantitative-genetic studies because partial dominance or heterosis may be removed by a suitably chosen transformation. With data transformations, even overdominance or better parent heterosis may disappear. When a data transformation is needed to meet the usual statistical assumptions such as normality and homogeneity of variance, a back-transformation to the original scale may be necessary, depending on what is deemed the appropriate scale for assessing genetic effects.  相似文献   

Analysis of Genebank Evaluation Data by using Geostatistical Methods     

Karin Hartung  Hans-Peter Piepho  Helmut Knüpffer 《Genetic Resources and Crop Evolution》2006,53(4):737-751

Genebanks often characterize accessions based on evaluation trials. This paper evaluates geostatistical methods as a tool to increase the utility of evaluation data. These methods were selected to overcome limitations resulting from a relative lack of replication and the scarcity of standards or check varieties. The data employed in the present study comprise nine characteristics of spring and winter barley, evaluated mostly as ratings. Ratings with quasi-metric scales were transformed by using the folded exponential transformation. To estimate the genetic component of the total effect, we compared two methods: Method 1 whereby a variogram is fitted by non-linear regression, and subsequently the implied spatial correlation is embedded into a mixed model analysis, which estimates the genetic effect by Best Linear Unbiased Prediction (BLUP); and Method 2 where each data value is re-estimated by kriging to correct for spatial effects and then the corrected data are submitted to a mixed model analysis. For practical application we propose Method 1 (though occasionally we met convergence problems): Fit the short range of the empirical variogram, visually choose the suitable covariance model. Use this and the initial values from non-linear regression fit with the mixed model, fixing the spatial parts at their starting values from non-linear regression, and estimate genetic effects by BLUP by using the fitted mixed model. To improve performance, we recommend that more standard or check varieties be used and, wherever possible, replace rating scales with metric scales or free-percentage scales (without categories).  相似文献   

Productivity of mixed versus pure stands of oak (Quercus petraea (Matt.) Liebl. and Quercus robur L.) and European beech (Fagus sylvatica L.) along an ecological gradient     

Hans Pretzsch  Kamil Bielak  Joachim Block  Arkadiusz Bruchwald  Jochen Dieler  Hans-Peter Ehrhart  Ulrich Kohnle  Jürgen Nagel  Hermann Spellmann  Michał Zasada  Andreas Zingg 《European Journal of Forest Research》2013,132(2):263-280

The mixture of beech (Fagus sylvatica L.) and oak (sessile oak, Quercus petraea (Matt.) Liebl., and pedunculate oak, Q. robur L.) is of considerable importance in Europe and will probably become even more important under climate change. Therefore, the performance of oak and beech in mixture was compared with the species’ growth in pure stands. Data from 37 long-term mixing experiments in Poland, Germany and Switzerland were pooled for analysis of mixing effects on stand productivity and possible interrelationships with mixing portions or site conditions. We found that on average, mixed stands of oak and beech exceeded biomass productivity in pure stands by 30 % or 1.7 t ha^?1 year^?1, as the growth of both species was benefitted by the mixture. However, that the interaction actually ranged from facilitation and overyielding on poor sites to underyielding on fertile sites triggered by competition. An empirically derived interaction model showed volume and dry mass growth changing in mixed stands from gains of 50 % to losses of 10 % depending on site conditions. It is concluded that the analysed mixture grows in accordance with the stress-gradient hypothesis and that our results suggest a site-specific relationship between species mixture and biomass productivity. As a consequence, an adequate species mix should result in increased productivity under steady state as well as climate change.  相似文献   

Production objectives and breeding goals of Sahiwal cattle keepers in Kenya and implications for a breeding programme     

Ilatsia ED  Roessler R  Kahi AK  Piepho HP  Zárate V 《Tropical animal health and production》2012,44(3):519-530

The Sahiwal breed has been used for upgrading the East African Zebu (EAZ) for improved milk production and growth performance in the southern rangelands of Kenya. Main users of this breed are Maasai pastoralists. Until now, there has been no deliberate effort to understand why these pastoralists specifically prefer to keep Sahiwal genetic resources as well as which traits are considered important by them and what is the underlying reason for this. However, this information is regarded vital for further development of the breed. A survey was conducted between May and October 2009 among Maasai pastoralists in Kajiado and Narok counties in the Southern part of Kenya, and private ranches and government farms to identify production objectives and breeding goals of Sahiwal cattle producers. Sahiwal genetic resources were mainly kept for domestic milk production and for revenue generation through milk sales and live animals. To a limited extent, they were kept for breeding and also for multiple objectives that included insurance against risks and social functions. Production aims were influenced to varying extents by various household and farmer characteristics. Sahiwal cattle and their crosses were generally perceived to be better with respect to productive traits and fertility traits when compared to the EAZ. However, the EAZ was rated higher with respect to adaptation traits. The breeding objective traits of primary importance were high milk yield and big body size, good reproductive efficiency and relatively good adaptation to local production conditions. Performance and functional traits are important breeding goals that play a major role in fulfilling the multiple production objectives. This forms the basis for the optimisation of a breeding programme for sustainable utilisation to meet the needs of Sahiwal cattle producers.  相似文献   

Untersuchungsergebnisse zur Spinnmilbenbekämpfung in der Innenraumbegrünung und unter Glas mit Stethorus punctillum (Weise)     

Jana Pöhle  Barbara Jäckel  Hans-Peter Plate 《Gesunde Pflanzen》2002,54(7):227-234

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Wirkung von Neem-Produkten auf höhere Pflanzen und ihre mögliche Nutzung zur Reduzierung der Seitentriebe von Kulturpflanzen sowie zur Unkrautbekämpfung – eine Bestandsaufnahme     

Hans-Peter Malkomes 《Gesunde Pflanzen》2006,58(2):93-98

The neem tree (Azadirachta indica A. Juss) offers many possibilities of usage. In plant protection mostly the insecticidal activity of neem products is important. In different parts of the plant several biologically active substances occur. One is the active ingredient azadirachtin, which already is commercially used as an insecticide against insect pests. Some active ingredients of neem may be systemically taken up by the treated plants. Often a rapid decomposition occurred which was enhanced by UV radiation. Therefore formulated neem products often need a UV blocker to elongate their activity. After the application of neem products within plant protection sometimes phytotoxic effects could be observed on different plant species. This phytotoxicity can be used to reduce suckers on tobacco plants and recently also on eucalyptus plants. The existing trials to use neem products for weed control mostly concentrated on the direct treatment of some parasitic weeds like Cuscuta, Orobanche and Striga as well as on a few other weeds (e.g. Echinochloa crus-galli). Mostly the growth of the weeds which were often repeatedly treated with high dosages was reduced, but many plants remained still alive. At present the potential of neem products for an effective weed control is not sufficiently investigated. As a consequence of some already known insecticidal and microbiocidal activities of many neem products also side effects on parts of the epigeic and soil fauna and on the nitrification should be considered after usage for weed control.  相似文献   

Fire place preferences of forest visitors in northwestern Switzerland: Implications for the management of picnic sites   总被引：1，自引：0，他引：1  

K. Tessa Hegetschweiler  Hans-Peter Rusterholz  Bruno Baur 《Urban Forestry & Urban Greening》2007,6(2):73-81

Some recreational activities in urban forests can cause extensive damage to soil and vegetation. In Switzerland, forest visitors frequently build fires outside picnic sites for barbecuing. This indicates that the existing picnic sites are either not attractive enough for these visitors, or that there are not enough sites for all the visitors during peak days. We used an on-site survey to assess the requirements of picnickers in two forest areas in the vicinity of Basle. Results showed that the existing picnic sites do not meet the requirements of some visitor groups, causing the respective visitors to make their own fires in locations that suit them better. There was a preference for sites near streams, away from forest roads and close to open spaces. Furthermore, while some visitors highly appreciated the well-equipped official sites, others preferred more natural infrastructure with pieces of stones forming a fire ring rather than concrete rims, and logs to sit on instead of benches. Picnic sites that are closer to the requirements of visitors who normally steer away from official sites might reduce the number of self-made fire rings. The study shows that understanding visitor behaviour is a prerequisite for the implementation of measures to reduce ecological impacts.  相似文献