Analysis Of Drought Resistance And Diosgenin Content On Dioscorea Nipponica Of Different Provenances In Shanxi

This paper took annual seedings of Dioscorea nipponica from 3 provenances (including Manghe, Pangquangou and Guancenshan) in Shanxi province as test materials, comprehensive analyzed the drought resistance of different provenances according to the change features of physiology and photosynthesis on seedlings by drought treatments; determined the content of D. nipponica rhizome diosgenin from 3 provenances at the same time. Based on above results, screened the fine provenance of this species. The main conclusions were as follows:(1) The effects of drought stress on antioxidant system of seedlingsThe SOD activity of seedlings from Manghe and Pangquangou increased firstly and dropped later with the duration of drought; the activity of SOD of Guancenshan experienced rise-decline-rise change trend; the SOD activity of 3 provenances all reached the highest level by light stress. As the stress of drought was intensified, the CAT activity of D. nipponica showed a rising trend in general; the CAT activity reached the highest level by severe stress. Under moderate stress, the MDA content of Manghe and Pangquangou increased obviously, arrived at the highest level, the MDA content began to decline later, but under severe stress, the content rised again; the MDA of Guancenshan increased gradually with the drought lasted, the content was the highest under severe stress.(2) The effects of drought stress on osmotic adjustment substances of seedlingsThe Pro of Manghe and Pangquangou had a continuous upwarding trend under drought stress, arrived at the highest level under severe stress; the Pro content of Guancenshan arrived at the highest level under light stress, then declined when the drought stress intensified. The soluble sugar content of Manghe arrived at the highest level under light stress, then began to increase gradually, the content was the highest under severe stress, the soluble protein content experienced a drop-rise-drop change trend, the content reached the highest level under moderate stress; the soluble sugar content and the soluble protein content of Pangquangou reached the highest level under light stress and declined afterwards; the soluble sugar content and the soluble protein content of Guancenshan arrived at the highest level under moderate stress and light stress, respectively, then decreased by the intensified drought stress.(3) The effects of drought stress on photosynthesis of seedlingsWith the stress intensification, the photosynthetic pigment contents of Manghe and Guancenshan increased firstly and then decreased, the content reached the highest level under moderate stress; while the photosynthetic pigment contents of Pangquangou gradually decreased, the content was the highest under severe stress. Pn, Tr, Gs and WUE of D. nipponica presented a obviously dropped tendency with the lasting of drought, all indexes arrived at the lowest level under severe stress. Ci showed an upward trend as a whole, the concentration was the highest under the severe stress.(4) The analysis of drought resistance on different provenancesThe sequence of drought resistance of D. nipponica from 3 provenances was:Pangquangou> Guancenshan> Manghe.(5) The content of rhizome diosgenin from different provenancesThe content of rhizome diosgenin from Manghe provenance was highest, followed by Pangquangou provenance, the content of Guancenshan provenance was the lowest.(6) Screening of high quality provenance on D. nipponicaSynthesized the drought resistance strength of different provenances and the content of diosgenin, preliminary screened Pangquangou as the suitable provenance for introduction and reproduction.