Zhang Q., Zhang F., Li B., Zhang L., Shi H. (2016): Production of tetraploid plants of Trollius chinensis Bunge induced by colchicine. Czech J. Genet. Plant Breed., 52: 34-38.Trollius chinensis Bunge is one of the important ornamental and medicinal plants cultivated in China. In this study, the tetraploid plants of Trollius chinensis were successfully induced by colchicine and their morphological, cytological and fertility characteristics were investigated. The results indicated that the tetraploid species of Trollius chinensis (2n = 4x = 32) was efficiently induced from the diploid species (2n = 2x = 16) by colchicine under 0.05% to 0.2% concentrations, with the best induction under treatment combinations of 0.1%, 24h duration and 0.2%, 12h duration. In comparison with the diploid plants, the tetraploid plants exhibited dramatically varied phenotypic features, showing increased leaf length and width, petiole, flower and pollen diameters. In addition, they also exhibited increased stomatal size and chloroplast numbers in guard cells. Tetraploidy reduced the pollen fertility. Nevertheless, the maintenance of female fertility makes the tetraploid a potential germplasm for further polyploid breeding. Our investigation provides a potential design for an effective pathway to generate varieties of this plant species with chromosome doubling.

Superconductivity and structural properties of Ti70−xZr30Nbx have been systematically investigated for x ranging from 0 to 60. Superconductivity is observed in the cubic β-phase with 10 x 60. Moreover, evident modifications in superconductivity and superstructure, being interpreted as Nb and Ti local orders, are discovered in samples with 25 x 50. This superstructure phase in general coexists with the cubic β-phase and yields two superconducting transitions in the superconducting materials. Electronic structure calculations reveal a relatively higher density of states for the superstructure phase at the Fermi level, therefore a strong electron-phonon coupling and higher superconducting Tc are expected in agreement with the experimental data.