Are early somatic embryos of the norway spruce (Picea abies (L.) Karst.) organised?

Background Somatic embryogenesis in conifer species has great potential for the forestry industry. Hence, a number of methods have been developed for their efficient and rapid propagation through somatic embryogenesis. Although information is available regarding the previous process-mediated generation of embryogenic cells to form somatic embryos, there is a dearth of information in the literature on the detailed structure of these clusters. Methodology/Principal Findings The main aim of this study was to provide a more detailed structure of the embryogenic tissue clusters obtained through the in vitro propagation of the Norway spruce (Picea abies (L.) Karst.). We primarily focused on the growth of early somatic embryos (ESEs). The data on ESE growth suggested that there may be clear distinctions between their inner and outer regions. Therefore, we selected ESEs collected on the 56th day after sub-cultivation to dissect the homogeneity of the ESE clusters. Two colourimetric assays (acetocarmine and fluorescein diacetate/propidium iodide staining) and one metabolic assay based on the use of 2,3,5-triphenyltetrazolium chloride uncovered large differences in the metabolic activity inside the cluster. Next, we performed nuclear magnetic resonance measurements. The ESE cluster seemed to be compactly aggregated during the first four weeks of cultivation; thereafter, the difference between the 1H nuclei concentration in the inner and outer clusters was more evident. There were clear differences in the visual appearance of embryos from the outer and inner regions. Finally, a cluster was divided into six parts (three each from the inner and the outer regions of the embryo) to determine their growth and viability. The innermost embryos (centripetally towards the cluster centre) could grow after sub-cultivation but exhibited the slowest rate and required the longest time to reach the common growth rate. To confirm our hypothesis on the organisation of the ESE cluster, we investigated the effect of cluster orientation on the cultivation medium and the influence of the change of the cluster’s three-dimensional orientation on its development. Maintaining the same position when transferring ESEs into new cultivation medium seemed to be necessary because changes in the orientation significantly affected ESE growth. Conclusions and Significance This work illustrated the possible inner organisation of ESEs. The outer layer of ESEs is formed by individual somatic embryos with high metabolic activity (and with high demands for nutrients, oxygen and water), while an embryonal group is directed outside of the ESE cluster. Somatic embryos with depressed metabolic activity were localised in the inner regions, where these embryonic tissues probably have a very important transport function

Optical studies of the upper atmosphere

iv, 146 leaves : ill., appendicesThesis (Ph.D.)--University of Adelaide, Dept. of Physics, 197

Wavelet Denoising of NMR Signal Using QMF Filter Bank Designed by Remez Algorithm

The wavelet transform is an up-to-date method for digital signal processing used in many branches of technofogy. One of its applications is the suppression of noise in useful signal. The paper deals with suppressing noise in a signal scanned on the NMR tomograph. The method of sub-band threslholding using the wavelet transform is discussed. This methotd is used in double denoising filtering of an FID signal and an instantaneous frequency signal. Using a filter bank with uniform ripple, designed by the Remez algorithm, is of advantage

Heteronuclear broadband spin-flip decoupling with adiabatic pulses

NRC publication: Ye

Use of magnetic resonance to determine the circumference of radial slices of Norway spruce

In the study of the growth of softwoods an interesting parameter is the rate of the growth of their needles. This parameter is significant in the evaluation of how economically trees use water, in particular the consumption of water in their growth in thickness and height. This is important in the study of the assimilation characteristics of plants and in the determination of physiological parameters of woods. The aim of the present study is to calculate, as accurately as possible, the total surface of Norway spruce needles on the basis of the circumference and shape of their radial slices

Experiments with the Effect of Non-Homogenous Parts into Materials

The article describes possibility of the deformity magnetic field numerical modeling into surroundings of the measured dia – paramagnetic specimens. This deformation study is given for the purposes MR measuring, where MR images are deformed from the point of view of susceptibility heterogeneous materials. For the numerical simulation was chosen elementary configuration. The results was verified by MR experimental measurement. As the MR measurement method was used techniques of the gradient echo

Determination of viability of regions of <i>Picea abies</i> embryos (vital staining).

<p>(<b>A</b>) A six week old cluster of ESEs was divided into six parts for subsequent cultivation. (<b>B</b>) Dependence of ESE viability on the cultivation time, which was detected by IA coupled with a fluorescence microscope. Embryos (~1 mg) used for the viability determination were prepared from six regions of the cluster. The cell material was mixed with fluorescein diacetate (FDA) and propidium iodide (PII), and the fluorescence was detected after 5 min by fluorescence microscopy. The percentage of green areas in the compact embryonal group of the embryos (marked by frames) was used to indicate live cells. Insets: upper inset–early somatic embryo (obtained from section 6b) stained with FDA/PI; bottom inset–early somatic embryo (obtained from section 1a) stained with FDA/PI. Average viability changes determined by (<b>C</b>) double FDA/PI staining and (<b>D</b>) esterase activity determination according to cultivation.</p

Comparison of the water volume in ESE clusters by NMR.

<p>Volume of dry substances in ESE clusters over time. Nuclear magnetic resonance was used to calculate the number of ¹H nuclei (colour scale). This number corresponds with the volume of water in the ESE clusters (dry substance in clusters). * The formation of a cavity.</p

<i>Picea abies</i> embryogenic culture.

<p>Growth curve of the embryogenic culture over 42 and 56 days (<b>inset</b>). The average area of a cluster was 46 mm² and its fresh weight was 110 mg at the beginning of the experiment. The values represent an average of 10 clusters.</p