In this study, in vitro induction of tetraploid Lychnis senno Siebold et Zucc. and its cytological and morphological characterization were conducted. For polyploid induction, nodal segments with axillary buds from in vitro grown plants were kept for 3 days in MS (Murashige and Skoog, 1962) liquid or solid media added with a series of concentrations of colchicine. Out of total 588 recovered plants, 15 tetraploids and 6 mixoploids determined by flow cytometry analysis were obtained. The tetraploid contained 48 chromosomes, twice the normal diploid number of 24, as observed under light microscope. The tetraploid plants exhibited much larger but less stomata than diploid plants. Moreover, significant differences in stem height and leaf size between the diploid and tetraploid plants were noted. The tetraploid plants were more compact than diploids.

Abstract.The thermister based temperature measurement scheme is widely applied for its low cost, strong stability and well flexibility. As the property between resistance and temperature is nonlinear, the practical application of thermister usually relies on the method of table look-up. Inevitably, that leads to the problems of poor versatility and large memory cost. Based on the analyses of resistance and temperature property, we propose an optimal linearization method of parameter design for NTC thermister interface circuit in this paper. The proposed approach is simple, but has a good linearity and high sensitivity. Test results are given to support the theoretical analyses and conclusions.