Solid-Liquid Equilibrium in Ternary System RbCl plus Polyethylene Glycol PEG1000+H2O at 288.15, 298.15, and 308.15 K
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
Authors: Li, Maolan; Wang, Lin; Zheng, Hong; Wu, Hong; Zeng, Ying; Yu, Xudong
Abstract
Phase diagrams, densities, and refractive indices of RbCl + polyethylene glycol (PEG) 1000 + H2O saturated systems at 288.15, 298.15, and 308.15 K were determined. Furthermore, a four-parameter nonlinear equation developed by Hu was used to analyze the experimental data. For the ternary system RbCl + PEG1000 + H2O, the salting-out ratio of PEG1000 on RbCl decreases with temperature, the equilibrium area containing the solid phase of RbCl and saturated liquid phase increases with the temperature. The solubility of RbCl and density decrease, while the refractive indices of the solution increase with the addition of PEG1000 in the solution.
DNA barcoding and molecular phylogeny indicate that three members of the "morning glory" (Ipomoea nil species complex) are conspecific
BIOLOGIA
Authors: Zhao, Hong; Tao, Weiqi; Zhang, Wei
Abstract
The Ipomoea nil species complex, commonly known as "morning glories", are common and economically important weeds throughout the world. However, their confusing taxonomy can limit their further utilization and management. Here, DNA barcoding analyses were performed based on ITS and rbcL regions of 64 samples, covering almost all morphological variants of this species complex, to test whether the named species can be distinguished from each other. Multiple phylogenetic analyses, including parsimony, maximum likelihood and Bayesian inference were also carried out to assess their relationships. Our results showed that none of the nominal species can be successfully identified because none of them are exclusive lineages. We propose that I. hederacea, I. nil and I. purpurea belong to a single biological species. In consideration of their diverse habitats and phenotypic plasticity, we suggest that I. hederacea, and I. purpurea should be at the best regarded as two ecotypes.