Objective To study rDNA ITS sequence similarities and differences between the de-virus seedlings and outside seedlings of Pseudostellaria heterophylla. Methods The sequences of ITS region (including ITS1, ITS2, and 5.8S) from nine de-virus seedlings and four outside seedlings were studied by the method of DNA sequence analysis. Results There were the same sequences in 5.8S region between the de-virus seedlings and outside seedlings of P. heterophylla. Variable sites lay in the initial position of ITS1 and termination of ITS2 basically. The de-virus seedlings from Liyang (Jiangsu Province) and Xuancheng (Anhui Province) had more variable sites. Phylogenetic dendrogram based on ITS was constructed by using UPGMA methods, which showed the inherent relation at the level of molecular biology. Conclusion The analysis of rDNA ITS of P. heterophylla has further clarified the inherit stability of de-virus seedlings at the molecular level.

OBJECTIVEIn order to find the new varieties with different horticultural characters, and investigate the mutation effects of seeds of Dioscorea zingerbrensis.

METHODThe seeds were carried by a satellite into space and recovered. The space mutation effect on the germination, seedling growth, chromosomes and rhizome diosgenin content of SP, populations of D. zingerbrensis were investigated.

RESULTStimulated by space environment, the seed possessed the fast germinating characteristics. Germination rate showed no change. It was also found that a few plants were aneuploid or tetraploid. Fresh rhizome weight and rhizome diosgenin content in the second year plant were remarkably higher than those of the control. However, the increasing of third year plant was slow down, and rhizome diosgenin content in the third year plant declined simultaneously.

CONCLUSIONThe space environment showed stimulating effects on seed germination, fresh rhizome weight and rhizome diosgenin content.

Dioscorea ; chemistry ; genetics ; physiology ; Extraterrestrial Environment ; Germination ; Mutation ; Plant Extracts ; chemistry ; Seedlings ; chemistry ; genetics ; physiology