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High-throughput deep-sequencing technology and bioinformatics analysis of the small RNA (sRNA) population isolated from plants allows universal virus detection and complete virome reconstruction for a given sample. In the present sRNA deep-sequencing analysis of virus-infected wheat samples in the Czech Republic, samples were firstly tested for barley yellow dwarf viruses (BYDVs), wheat streak mosaic virus (WSMV) and wheat dwarf virus (WDV) using ELISA, RT-PCR and PCR. Subsequent sRNA sequencing of these samples yielded more than ~60 million single-end 50-bp reads with high confidence for nine field samples of wheat. Overall, 16.5% of reads were virus-specific and 83.5% were mapped to the host. More 21-nt reads (~7.7E+06 reads) were found than 24-nt (~6.20E+06 reads) or 22-nt (~4.30E+06 reads) reads. De novoassembly of the high-quality contigs revealed the presence of three earlier reported viruses in the Czech Republic: BYDVs (31.48%), WSMV (24.23%) and WDV (26.66%). We also showed the presence of cereal yellow dwarf virus (14.33%; two species CYDV-RPS and CYDV-RPV (family Luteoviridae/Polerovirus) and wheat yellow dwarf virus (WYDV, 3.30%; Luteoviridae). Phylogenetic analysis showed CYDV and WYDV grouped separately from BYDVs. Furthermore, several recombination breakpoints were found among the groups of yellow dwarf viruses (BYDVs, CYDV, and WYDV). Using RNA deep sequencing, we confirmed the presence of the three known viruses (BYDVs, WSMV, and WDV) and the first record of two species of CYDV and WYDV in wheat in the Czech Republic.

Ferroelectric phenomena in solids have been studied for seventy years. The history of their research is divided into five periods which are briefly characterized. Materials basis known today is overviewed. Factors motivating ferroelectric research are discussed and present status of practical applications is shown. Finally some topical problems promising interesting results are mentioned.

In a planar sample of SmC* liquid crystal helicoidal structure exists in the bulk while the surface layers are unwound. Connection between these two regions is mediated by line defects, 2π disclinations, responsible for the observed line texture. Thin planar samples may be spontaneously unwound and exist in twisted or uniform configurations. Experiments reveal that helix unwinding in an electric field is a more complex process than considered by previous theories. It involves movement of disclinations and their annihilation, reorientation of molecules in the bulk and domain processes in the surface layer. Ferroelectric-like properties of thin samples have application perspectives.

Conditions necessary for reducing the number of ferroelectric or ferroelastic domains by enforcing the crystal to exist in one enantiomorphic form, which can be achieved in principle by suitable chiral dopants, have been determined by means of symmetry analysis. The results are illustrated on examples representing several classes of phase transitions.

Dielectric permittivity of ferroelectric liquid crystals has been measured in dependence on temperature, bias electric field and frequency. It is shown that the permittivity increase occurs only below TC in ferroelectric SmC* phase and it is a consequence of real defect structure in planar samples.

AbstractThe proceedings of MEIPIC-3 is surely the appropriate forum to pay tribute to Professor Hans Schmid of the University of Geneva, on the occasion of his 65th birthday; in a sense a tribute of a child to the father since it was he who established this series of conferences and since its topic is surely not showing any marks of aging.

The complex permittivity of multidomain single crystals of BaTiO3was measured in the decimetre and centimetre wave bands and it was proved that in this frequency region there is dispersion of the permittivity. Apparatus for measuring the permittivity of substances with a high e' is described and the influence of the inhomogeneity of the field in the sample on the characteristics of the cavity resonator is calculated. Present theories of the high-frequency properties of BaTiO3 are discussed from the point of view of the experimental results.

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Spontaneous birefringence ?s?nin the INC and C phases of Rb2ZnCl4crystals has been evaluated and shown to consist of contributions proportional to and , rdenoting the order parameter modulus. Jump-like changes in ?nof the order of 10-6are observed at the INC-C transition. It is shown that they can be explained by a change D/\cong0.25% and by the occurrence of another contribution in the INC phase. The latter could originate from the fact that the light propagation may be affected by spatial modulation of optical permittivities. If temperature is cycled in the INC phase only, no hysteresis in ?nis observed. This shows that-unlike static permittivity-optical properties of Rb2ZnCl4are not sensitive to which is proportional to soliton density.