摘要:

SUMMARYThe time course of aerobic photobleaching of the chlorophyllb‐free algaVischeria stellatais of a biphasic nature. Initially the bleaching rate is about 10 times higher than under prolonged exposure to high light intensities.Centrifugation considerably enhances the aerobic photobleaching rate of chloroplast fragments. Concomittantly the 685 nm component of the low‐temperature fluorescence spectrum is markedly increased. The relationship between the intensity of this component and the bleaching capacity resembles an exponential one.As the photobleaching proceeds, the red absorption maximum shifts to longer wavelengths. This relationship is linear.Both photosystems are involved in the initial bleaching.The results are discussed in terms of the spill‐over model for excitation energy in photosynt

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00181.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYAscoidea corymbosaW. Gams&Grinbergs n. spec. was isolated repeatedly from bast ofAraucaria araucariain Chile. It is characterized by corymbose asci with attenuated base and small hat‐shaped ascospores. The production of asci is very abundan

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00182.x

年代:1970

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00183.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe genusAcrophialophorais characterized by flask‐shaped tapering phialides which are borne in verticils on unbranched, erect, darkly pigmented conidiophores or on undifferentiated aerial hyphae. Examination of the type culture ofPaecilomyces fusisporusSaksena (1953) showed that this fungus belongs toAcrophialophora. Amongst some fungus cultures sent for identification to the CBS from Pakistan, Turkey, and Germany, a third species ofAcrophialophorawas found. Because of its smooth conidia the nameAcrophialophora levisis propose

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00184.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYIn white light filtered through leaves the ratio red – far red is strongly shifted to the far red side. Such light prevents germination of photoblastic seeds.Several species of weed seeds were investigated. It is concluded that the spectral composition of the light in a forest must be very important for the density and the composition of the undergrowt

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00185.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe influence of DCMU on the photosynthesis and the uptake of chloride and rubidium ions byVallisnerialeaves was studied.The photosynthesis was more reduced by DCMU than was the ion uptake. The rubidium uptake is somewhat more sensitive to DCMU than the chloride uptake.The provisional conclusion is that both the rubidium and chloride uptake can be supported by cyclic photophosphorylation.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00186.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe effect of coconut water (CW) and of 2,4‐dichlorophenoxyacetic acid (2,4‐D), applied singly or in combination, to clonal material of excised roots of tomato cv. ‘Moneydor’ was investigated. Distinct stimulatory effects on the growth of roots were obtained in both cases. CW showed its highest growth action when applied at low concentrations (0.025% and 0.050% v/v) to roots incubated in darkness. Certain combinations of CW and 2,4‐D gave a strikingly high growth rate which exceeded that of the control with or without CW. Acombination of 2 × 10−4µg. ml of 2,4‐D with 0.050 % (v/v) of CW gave maximum growth stimulation without toxicity to

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00187.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYDuring summer 1967 an ecological study of the zonation of different macrophytes was made in the three basins of Chielgat, Venematen and Zuideindigerwiede in North‐West Overijssel, the Netherlands. Chemical properties of sapropels, microclimatic conditions and composition of mud gases in habitats of different macrophyte zones were studied.The three basins show various degrees of trophism and different qualities of humic substances in sapropels. The habitats of different macrophytes in the same basin are also different.Each vegetation zone is characterized by a special temperature course in different water and air layers. The temperature course is dependent on the position and structure of the vegetation zone and on weather conditions. Water temperature is influenced by the duration of insolation, and by the direction and strength of wind. Time‐shifts in the warming‐up of the lower water layers are also of interest.The relative amounts of C02, 02, N2and CH4were estimated both under and in the plant cover of the vegetation zones under study. While under the plant cover CH4prevails in the gas mixture, in the plant cover C02, 02and N2are of higher importance. The amount of C02+ CH4on the one hand and the amount of N2on the other hand reflect the outputs of C and N metabolisms which take place in the basins. The gaseous output of C and N metabolisms in the basins under study are related to the trophisms of individual b

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00188.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYZygotes ofBryopsis plumosafrom Naples, Banyuls, and Biarritz grew into filamentous germlings which divided into stephanokontic zoids. Some of the germlings from Naples and Banyuls developed directly into newBryopsisplants. In culture these germlings have a longer “dormancy” period than those ofBryopsis plumosacollected in more northern regions (Zeeland, Roscoff).Bryopsis plumosafrom Naples could interbreed with Roscoff material to produce germlings that only developed through stephanokontic zoids.Bryopsis plumosafrom Naples could also interbreed with Zeeland material and produced germlings that only developed directly into newBryopsisplants (which is characteristic forBryopsis plumosafrom Zeeland). Zinc‐chlor‐iodide and Congo red positively stain the walls of theBryopsisphase, and negatively the walls of the germling phase. On the basis of these results the life‐histories and the site where meiosis takes place in the life‐history ofBryopsis plumosaar

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00189.x

年代:1970

数据来源: WILEY

摘要:

SUMMARYWith the aid of a modified single‐stage replica method the taxonomic identification of pollen from Chenopodiaceae and Amaranthaceae to the generic level appears to be possible. The implications of these identifications for vegetation reconstruction and the interpretation of pollen diagrams are discusse

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1970.tb00190.x

年代:1970

数据来源: WILEY