Authors:H. Dębski, W. Wiczkowski, D. Szawara-Nowak, N. Bączek, M. Szwed, and M. Horbowicz
The effects of two light intensities on the concentration of several flavonoids were investigated in the cotyledons of common buckwheat seedlings. The study was performed on four days old seedlings of cvs. Hruszowska, Panda, Kora and Red Corolla. One group of seedlings was grown under exposure to 180 ± 20 μmol · m−2 · s−1 photosynthetically active radiation, whereas the other group was exposed to 360 ± 20 μmol · m−2 · s−1. The experiment lasted 5 days. The results revealed that light intensity induces changes in the levels of flavonols and flavones. Increased light intensity contributed to a decrease in the concentrations of all flavone C-glucosides: orientin (luteolin-8-C-glucoside) and iso-orientin (luteolin-6-C-glucoside), and apigenin: vitexin (apigenin-8-C-glucoside) and iso-vitexin (apigenin-6-C-glucoside). Simultaneously, a substantial increase in the content of flavonols, i.e. quercetin O-glycosides, was found. To the best of our knowledge, this is the first evidence to demonstrate the contrary responses of plant flavonols and flavones to light intensity. The content of anthocyanin also increased under exposure to higher light intensity. Our results indicate that quercetin O-glycosides can play a similar role to anthocyanins in the cotyledons of common buckwheat seedlings. Results of correlation analysis indicate that the increase in flavonol and anthocyanin concentrations in response to higher light intensity is maintained through reduced accumulation of flavones and proanthocyanidins.
It has been shown that simultaneous measurements of reflected light intensity (RLI) with DSC can give additional and valuable
information for the thermal analysis of materials including pure organic and inorganic chemicals, natural and synthetic polymers
This paper extends the range of polymers studied and examines the possibility of improving the reproducibility and quantitative
nature of RLI measurements. Polymer crystallisation, the curing of epoxy resins, the action of fire retardant additives and
the degradation of polymers and proteins are among the systems studied.
Authors:E. Skrzypek, M. Warchoł, I. Czyczyło-Mysza, I. Marcińska, A. Nowakowska, K. Dziurka, K. Juzoń, and A. Noga
Oat haploid embryos were obtained by wide crossing with maize. The effect of light intensity during the growing period of donor plants (450 and 800 µmol m−2 s−1) and in vitro cultures (20, 40, 70 and 110 µmol m−2 s−1) was examined for the induction and development of oat DH lines. Oat florets (26008) from 32 genotypes were pollinated with maize and treated with 2,4-dichlorophenoxyacetic acid. All the tested genotypes formed more haploid embryos when donor plants were grown in a greenhouse (9.4%) compared to a growth chamber (6.1%). The light intensity of 110 µmol m−2 s−1 during in vitro culture resulted in the highest percentage of embryo germination (38.9%), conversion into plants (36.4%) and DH line production (9.2%) when compared with lower light intensities (20, 40 and 70 µmol m−2 s−1). The results show that the growth conditions of the donor plant and light intensity during in vitro culture can affect the development of haploid embryos. This fact may have an impact on oat breeding programs using oat × maize crosses.
Authors:C. A. Gracia-Fernández, P. Davies, S. Gómez-Barreiro, Beceiro J. López, J. Tarrío-Saavedra, and R. Artiaga
constrained to 350–500 nm by insertion of an optical filter in the light path. The lightintensity can be adjusted between 1 and 2000 mW cm −2 . Since the TMDSC instrument used in this work is furnished with the Tzero (tm) technology, it is possible to perform
Authors:Mohd Abu Bakar, Zoltan Nagy, and Christopher Rielly
by computing the total lightintensity. The latter may be calculated as the sum or average of the grey levels in all pixel (pixel value ranges from black = 0 to white = 255). As the image becomes brighter, the lightintensity value becomes higher. The
The dormancy of potato microtubers produced under different photoperiodic treatments and light intensities was investigated in the varieties Desiree and Gülbaba. The dormant period was defined as the period between harvest or tuber initiation and the end of dormancy. The effects of environmental factors could be detected due to the use of a hormone-free tuber-producing system. Combined treatments had a slight effect on dormancy, while different light intensities influenced it considerably. The lower the light intensity the longer the dormant period for both cultivars. The effects of light intensities depended on the photoperiodic treatments applied for tuber induction.