The Isolation and Identification of Infectious Bronchitis Virus PTFY Strain in Muscovy Ducks / 病毒学报

In July 2009, some farms of breeding Muscovy ducks on the peak of egg laying suffered the decrease of hatching rate and the quality of the eggs showing low mortality and no evident respiratory symptoms. The swelling and congestive ovary was visible after autopsy. This study was brought out for the diagnosis of these cases. The virus was isolated and identified by the methods of virus culture in chicken embryo, physical and chemical properties test, hemagglutinin test, NDV (Newcastle diseases Virus) interference test, electron microscope observation, pathogenicity test and the gene sequence analysis. The results indicated the virus showed the characters of inducing dwarf embryo after inocubation, the sensibility to lipid solvent and the hemagglutination capacity after pancreatic enzyme treatment, the typical morphology of coronavirus, the interference to NDV replication and the homology among 84.7% - 99% of the particial N gene sequences to the reference IBV (Avian infectious bronchitis virus) strains. The strain was identified as IBV isolate and this study confirmed the pathogenicity of IBV to Muscovy ducks.

Seedling botanical characters and determination of effective components on Dioscorea zingerbrensis by space mutation / 中国中药杂志

<p><b>OBJECTIVE</b>In order to find the new varieties with different horticultural characters, and investigate the mutation effects of seeds of Dioscorea zingerbrensis.</p><p><b>METHOD</b>The 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.</p><p><b>RESULT</b>Stimulated 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.</p><p><b>CONCLUSION</b>The space environment showed stimulating effects on seed germination, fresh rhizome weight and rhizome diosgenin content.</p>