Archiv Volume V

 

Kopta, T.: Evaluation of non-traditional vegetable species (Chinese broccoli and Asian radish) under the condition of the Czech Republic. Folia univ. agric. et silvic. Mendel. Brun., 2012, Vol. V, No. 1
This work deals with the issue of organic production of non-traditional vegetable species -- Chinese broccoli (Brassica alboglabra L. H. Bailey) and Asian radish (Raphanus sativus L.) in the Czech Republic. The quantitative and qualitative parameters of these species were tested on the premises of the certified organic field (Faculty of Horticulture, Lednice) in 2008--2009. Five cultivars of Chinese broccoli (Green Lance, Happy Rich, Hon Tsai Tai, Suiho, Summer Jean) and three cultivars of Asian radish (Jarola F1, Red Meat and Miyashige) were evaluated.
The results show the differences in yield parameters of particular cultivars (the average weight of stalk and the leaf area of Chinese broccoli, radish marketable yield). The content of the analyzed substances, particularly the content of the ascorbic acid, or some minerals, differs according to the cultivars. All the data were subject to the statistical processing in form of analysis of variance and subsequent testing methods to determine the differences in various factors. The expected factors were tested for correlation to find dependence.
Key words: Asian vegetables; organic farming; yield; chemical compound analysis

Šebánek, J., Kalousek, P.: Phytohormonal study of ontogenesis of woody plants and apical dominance (Hundred years of school of Rudolf Dostál). Folia univ. agric. et silvic. Mendel. Brun., 2012, Vol. V, No. 2
The monograph summarises some results of studies on the plant-hormonal substance of stages of ontogenesis of woody species obtained at the prof. R. Dostál scientific school of experimental plant morphology and hormonology at Mendel University in Brno in the past 60 years. Special attention is devoted to present studies of the nature of shoot branching, i.e. its apical dominance, which Dostál's scientific school had pursued since its establishment in 1908. As the first ontogenetic stage the focus is on seed germination, its stratification and senescence. Attention was also devoted to studies of growth correlations in seedlings of woody species. Characteristic of the juvenility stage of woody species is a low content of endogenous gibberellins. In terms of differentiation of vegetative buds the correlative (and not only protective) importance of scales was proved. The first leaves on prematurely outgrown annual shoots exhibit abnormal shapes which can be hypothetically interpreted as atavistic shapes. Flower differentiation was studied in Juglans regia. Here the formation of male flowers is stimulated by gibberellins, female by inhibitors. Spraying young leaves and twigs with IAA boosted the establishment of leaf buds to the detriment of anther catkins. The effect of triiodobenzoic acid (TIBA) was the opposite. Bud dormancy of woody species connected with hormonal inhibitions is indicated as endogenous. It usually starts in August and we can specify its beginning if we determine the time when the removal of leaves does not lead to bud growth in the axils any more. The end of endogenous dormancy can be specified if we determine the time when the twigs transferred into the warm greenhouse in winter begin to bud; usually in January or even as early as December when the endogenous dormancy changes into exogenous dormancy (forced by cold). In the course of 10 years the duration of endogenous dormancy of various woody species was estimated in this way indicating the period when cuttings should not be taken from the plant for rooting. In the study we also summarised the hormonal aspects of leaf senescence and abscission as an expression of programmed cell death. Senescence is inhibited not only by cytokinins, but also by auxin and benzolinone. IAA can simulate the correlative effect of the blade retarding the formation of the separating layer on the base of the petiole. Discussed is the different effect of IAA when applied distally or proximally to the separating layer. Also explored was the branching of woody species as an expression of stem apical dominance. Dichasial sympodial branching which is typical of lilac (Syringa vulgaris) occurs when apical dominance connected with the dying-off of the apical stem meristem declines and is connected with the increase in endogenous cytokinins and decrease in endogenous IAA and ABA. These hormonal changes accompany the decline of apical dominance also in herbs. The first explanation of the apical dominance was that it is a consequence of competition between the shoot apex and axillary buds for nutrient substances. However pioneer studies of Rudolf Dostál with pea seedlings showed that not substances of a nutritive character but those of a growth--regulating character play the decisive role in the regulation of this phenomenon. Later the inhibitory effect of the shoot apex was successfully simulated by an exogenous application of the plant hormone auxin. Of crucial importance for maintaining the growth inhibition of axillary buds is the polar transport of auxin in the stem which runs from the site of biosynthesis in the shoot apex to the stem base and is mediated by the activity of specific carriers. The precise mechanism of auxin action in correlative inhibition of growth of axillary buds has not yet been elucidated. It was explained as a consequence of insufficient development of vascular strands between inhibited axillary bud and vasculature of the main stem or as a result of nutrient transport towards the source of auxin which is represented by the shoot apex. Still very topical is Bangerth's theory on the autoinhibition of polar auxin transport according to which auxin transport from a primarily induced sink, such as the shoot apex, blocks the transport of auxin from sinks induced later which are axillary buds, and the condition is that the export of auxin from the bud is a necessary factor for its growth. Another possibility is, that auxin affects the endogenous levels of other plant hormones which can then directly influence the growth activity of axillary buds. In this context, the possible roles of cytokinins, gibberellins, abscisic acid and ethylene in regulation of apical dominance have been studied.
Keywords: phytohormones and woody plants; seed germination; differentiation of buds; juvenility and senescence; phytohormones and apical dominance; polar auxin transport, axillary bud

Pospíšilová, Ľ.: Non-degradation methods of studying natural humic substances quality. Folia univ. agric. et silvic. Mendel. Brun., 2012, Vol. V, No. 3
The paper gives results of quality evaluation of natural humic substances. Non-destructive spectroscopic techniques for their identification such as SRATR FTIR, HATR FTIR, 3D EEM, SFS, EDXS and 13C NMR spectroscopy were used. Natural humic substances were isolated from soil, lignite, compost, and commercial lignohumate. The main attention was paid to the soil humic acids. Lignite represents a valuable organic substrate and one of the most attractive ways of non-energetic exploitation is humic substances source exploitation. Humic acids were isolated according to the standard international methods. Elemental composition was performed by PE 2400 CNS/O elemental analyzer. Similar features and differences in the chemical and structural composition are presented by measuring of absorbance in ultraviolet, visible and infrared spectral range. UV-VIS spectroscopy allowed us to divide them into several groups according to their maturity. Infrared spectroscopy evaluated their aromaticity, hydrophobicity, biological activity and functional groups content. The most aromatic and stabile were humic acids isolated from lignite, Chernozem and lignohumate. Hydrophobicity was the highest in humic acids isolated from Chernozems and the lowest in Cambisols. The highest biological activity had lignohumate sample, humic acids isolated from Cambisols (grassland soils) and compost. The less active were humic acids in Pseudogley. Some common bands and functional groups in infrared spectral region for all natural humic substances were determined. Very useful were measurements of fluorescence and application of 13C NMR spectroscopy. High resolution spectra give estimation of their structure, functional groups and aromaticity degree. We have found out that fluorescence of natural humic substances was caused by the presence of di-substituted coumarine, xantone or chinone, naphthalene and phenols in their molecule. 13C NMR spectroscopy assessed aromaticity indexes (α) of different origin humic substances. The highest aromaticity had humic acids isolated from lignite and Chernozems. The last corresponded with high content of aromatic groups in spectral regions 43 -- 106 ppm and 106 -- 157 ppm. Linear correlation between spectral indexes and chemical parameters was determined. Detailed chemical identification and spectral behaviour in different spectral regions could help us better understand these very flexible and complex substances. Our paper also confirmed that non-destructive spectral methods and techniques are sensible enough to characterized natural humic substances.
Keywords: natural humic substances; UV-VIS; SFS; IR and 13C NMR spectroscopy

 
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ISSN 1803-2109 (Print)