Cloning and bioinformatics analysis of abscisic acid 8‘-hydroxylase from Pseudostellariae Radix Q-TRAP-LC-MS/MS analysis on nucleosides in Pseudostellariae Radix with different processing methods Research model on commodity specification standard of radix Chinese materia medica Classification study on commodity specification and grade standard of Pseudostellariae Radix Rapid molecular identification of Pseudostellariae Radix