Die DouglasienwollausGilletteella cooleyi Gill. und ihre Bekämpfung

Ohne Zusammenfassung Mit 8 Abbildungen     

Seidenspinnerkokons aus den Jahren 1870 und 1940

Ohne Zusammenfassung     

Analysis and modeling of gas exchange processes in Scaevola aemula

Scaevola aemula is a popular ornamental crop cultivated as a bedding plant or for hanging baskets. We characterized gas exchange properties of S. aemula ‘New Wonder’ in response to photosynthetically active radiation (PAR), carbon dioxide concentration, and leaf temperature. Net CO₂ assimilation rate (A) was responsive to CO₂, exhibiting a saturation when intercellular CO₂ concentration (C_i) was greater than 600 μmol mol⁻¹. Net CO₂ assimilation rate and dark respiration rate (R_d) were 23.1 and 2.3 μmol m⁻² s⁻¹, respectively, at 25 °C and PAR = 1500 μmol m⁻² s⁻¹. Net CO₂ assimilation rates were similar at leaf temperatures between 20 and 30 °C but significantly reduced at 15 °C. These gas exchange results were used to test the extendibility of a coupled gas exchange model previously developed for cut-roses. Utilizing the gas exchange data measured at 25 °C leaf temperature, several model parameters were independently determined for S. aemula. Model predictions were then compared with observations at different leaf temperatures. The model predicted the rates of net CO₂ assimilation and transpiration of S. aemula reasonably well. Without additional calibration, the model was capable of predicting the temperature dependence of net CO₂ assimilation and transpiration rates. Applying the model to predict the effects of supplemental lighting and CO₂ enrichment on canopy photosynthesis and transpiration rates, we show that this model could be a useful tool for examining environmental control options for S. aemula production in the greenhouse.     

Die Gliederung der forstwirtschaftlichen Produktionslehre

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Recombinant virus vaccines--present status and future prospects

Several DNA viruses have recently emerged as useful eucaryotic vectors. The ability to incorporate large amounts of foreign DNA in the vaccinia virus genome without loss of infectivity, evidence to correct glycosylation and processing of expressed proteins and the wide host range of vaccinia virus all contribute to the versatility of this system as a research tool. The development of recombinant DNA technology and its use in genetic engineering has provided opportunities to construct DNA-recombinant viruses that can provide protection against a spectrum of diseases. A brief account is given of current developments and future prospects of DNA recombinant viruses, with particular reference to vaccinia virus.