50 Jahre Deutsche Gesellschaft für angewandte Entomologie     

Erwin Schimitchek 《Journal of pest science》1963,36(10):145-148

Ohne Zusammenfassung  相似文献   

Prof. Dr. Friedrich Zacher     

Erwin Schimitschek 《Journal of pest science》1962,35(4):58-59

Ohne Zusammenfassung  相似文献   

Über Insektenfunde aus der Römerzeit     

Schimitschek  Erwin 《Journal of pest science》1975,48(3):33-35

Journal of Pest Science - On insects found in excavations from the Roman Age. A review is given of the results of excavations made in several regions of Europe with regard to the insect fauna...  相似文献   

Do trees use reserve or newly assimilated carbon for their defense reactions? A 13C labeling approach with young Scots pines inoculated with a bark-beetle-associated fungus (Ophiostoma brunneo ciliatum)     

Natacha Guérard  Pascale Maillard  Claude Bréchet  François Lieutier  Erwin Dreyer 《Annals of Forest Science》2007,64(6):601-608

Three-year-old saplings of Pinus sylvestris L. were labeled with ¹³CO₂ prior to inoculating the trunk with Ophiostoma brunneo ciliatum, a blue-staining fungus usually associated to Ips sexdentatus. During incubation, half the trees were submitted to a severe drought that decreased photosynthesis and natural ¹³C content in non-labeled saplings. A large ¹³C-excess was obtained in wood and phloem, especially in the fractions of soluble proteins, starch and soluble sugars of labeled saplings. Drought increased ¹³C-excess, due to reduced photosynthesis and smaller dilution of ¹³C by the addition of newly assimilated ¹²C. The induced-reaction zones in inoculated saplings displayed large total C (58 g 100 g^?1) because of the accumulation of secondary metabolites. They also showed much larger ¹³C-excess than any other compartment: the contribution of stored C to the reaction zones was much higher than that of currently assimilated C. Moreover, drought lowered the contribution of the latter, as shown by the increase of ¹³C in the reaction zones. We conclude that stored C was readily mobilized for the construction of reaction tissues, and that the contribution of currently assimilated C was only minor.  相似文献   

Berichte     

Erwin Schimitschek  E. Sch  Dr. Else Jahn 《Journal of pest science》1979,52(9):141-144

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Photosynthetic responses to phosphorus nutrition in two-year-old maritime pine seedlings     

Loustau D  Brahim MB  Gaudillère JP  Dreyer E 《Tree physiology》1999,19(11):707-715

We analyzed processes limiting photosynthesis in two-year-old, container-grown Pinus pinaster Ait. seedlings subjected to phosphorus (P) deficiency. After withholding P for 3 months, seedlings were supplied P at four relative addition rates (0, 0.005, 0.01 and 0.02 day(-1)) in a nutrient recycling system. At Weeks 12 and 22, responses of photosynthesis to CO(2) and irradiance were measured and the following parameters derived: maximal velocity of carboxylation by Rubisco, V(m); apparent quantum efficiency of electron transport, alpha maximal electron transport rate, J(m); stomatal conductance and relative stomatal limitation of photosynthesis. At Week 22, these measurements were combined with concurrent measurements of chlorophyll fluorescence to determine the quantum yield of PSII, and a theoretical partitioning of total light-driven linear electron flow between fractions used to regenerate carboxylated and oxygenated RuBP. After 12 weeks of treatment, needle P concentrations ranged from 0.04 to 0.15 x 10(-2) g g(DW) (-1), and then remained constant until Week 22. Values of J(m), alpha and V(m) increased with increasing needle P concentration (from 30 to 133 &mgr;mol m(-2) s(-1), 0.02 to 0.25 mol mol(-1) and 13 to 78 &mgr;mol CO(2) m(-2) s(-1) at the lowest and highest needle P concentrations, respectively). Under ambient conditions, net assimilation rates in P-deficient seedlings were limited by V(m) under saturating irradiance, and by J(m) under limiting irradiance, but not by triose-P regeneration. There was no detectable change in the partitioning of total light-driven linear electron flow between the fractions used for carboxylation and oxygenation. Predawn photochemical efficiency of PSII was significantly reduced in seedlings with low P concentrations. Although stomatal conductance tended to decrease with decreasing needle P concentration, relative stomatal limitation was not significantly affected. At Week 22, there was an attenuation of the effects of P nutrition on V(m) and an increase in alpha and J(m) that was probably related to cessation of growth and the seasonal decline in natural irradiance.  相似文献   

Auswirkungen des Befalles vonDreyfusia (Adelges) Nüsslini C. B. auf den Wasserhaushalt und die lebende Rinde der Tanne     

Erwin Schimitschek  Elisabeth Wienke 《Journal of pest science》1967,40(11):166-171

Zusammenfassung Befall der Tannen durchDreyfusia Nüsslini bewirkt eine starke Störung ihres Wasserhaushaltes. Dies kommt darin zum Ausdruck, daß bei gleichalten befallenen Tannen gegenüber gesunden, nicht befallenen des gleichen Standortes zur gleichen Zeit je nach der Befallsstärke ein entsprechend starkes Absinken der Saftstromgeschwindigkeit sowie der Transpiration eintritt. Dieses Absinken geht bei starkem Befall durch die Tannentrieblaus so weit, daß der Tagesverlauf der Kurve der Saftstromgeschwindigkeit jener einer absterbenden Tanne gleicht. Der Befall bewirkt weiter Veränderungen in der lebenden Rinde des Stammes. Er wirkt sich auch auf den elektrischen Widerstand der lebenden Rinde aus. Der elektrische Widerstand der lebenden Rinde befallener Tannen ist geringer wie jener gesunder gleichalter Tannen am gleichen Standort.  相似文献   

Performance of soil-applied FeEDDHA isomers in delivering Fe to soybean plants in relation to the moment of application     

Schenkeveld WD  Reichwein AM  Bugter MH  Temminghoff EJ  van Riemsdijk WH 《Journal of agricultural and food chemistry》2010,58(24):12833-12839

FeEDDHA (iron(3+) ethylenediamine-N,N'-bis(hydroxyphenylacetic acid) products are commonly applied to mend and prevent Fe deficiency chlorosis in soil-grown crops. Plants mainly take up Fe in the progressed vegetative and in the reproductive stages. This study examined which of the principal constituents of FeEDDHA products (the isomers racemic o,o-FeEDDHA, meso o,o-FeEDDHA, and o,p-FeEDDHA), most effectively meets the Fe requirements of soybean plants (Glycine max (L.) Merr.) grown on calcareous soil in the aforementioned growth stages. FeEDDHA isomers were applied once, separately or in mixtures, at t = 0, in the progressed vegetative stage or in the reproductive stage. o,p-FeEDDHA did not significantly contribute to Fe uptake in either growth stage. Both racemic and meso o,o-FeEDDHA were effective in supplying plants with Fe, approximately to the same extent. The moment of application had a significant effect on yield and FeEDDHA pore water concentrations at harvest, but not on Fe uptake. To optimize yield while minimizing FeEDDHA dosage, FeEDDHA is best applied to soybean plants prior to the onset of chorosis.  相似文献   

Chemical conversion of alpha-keto acids in relation to flavor formation in fermented foods     

Smit BA  Engels WJ  Alewijn M  Lommerse GT  Kippersluijs EA  Wouters JT  Smit G 《Journal of agricultural and food chemistry》2004,52(5):1263-1268

Formation of flavor compounds from branched-chain alpha-keto acids in fermented foods such as cheese is believed to be mainly an enzymatic process, while the conversion of phenyl pyruvic acid, which is derived from phenylalanine, also proceeds chemically. In this research, the chemical conversion of alpha-keto acids to aldehydes with strong flavor characteristics was studied, with the main focus on the conversion of alpha-ketoisocaproic acid to the aldehyde 2-methylpropanal, and a manganese-catalyzed reaction mechanism is proposed for this conversion. The mechanism involves keto-enol tautomerism, enabling molecular oxygen to react with the beta-carbon atom of the alpha-keto acid, resulting in a peroxide. This peroxide can react in several ways, leading to unstable dioxylactone or noncyclic intermediates. These intermediates will break down into an aldehyde and oxalate or carbon oxides (CO and CO(2)). All the alpha-keto acids tested were converted at pH 5.5 and in the presence of manganese, although their conversion rates were rather diverse. This chemical reaction might provide new ways for controlling cheese flavor formation with the aim of acceleration of the ripening process or diversification of the flavor characteristics.  相似文献   

光照强度对植物光合作用的影向     

Jennifer Boldt  John Erwin  李平 《中国花卉园艺》2011,(12)

植物通过光合作用来增加体积和干重.提高光合作用效率也就意味着增加开花率、提高植物品质、促进植物的采后活力.而植物光合作用的强度和速率则与光强度、二氧化碳浓度和温度密切相关.  相似文献