| This study has been completed in the 5 floor platform of Standard floor of Shaanxi Normal University from June 2009 to December 2010, D. Zingiberensis variety 'Anjiang 3'roots, which provided by Turmeric research center in Xunyang County, Shaanxi Province, were taken as the material in this experiment.We adopted the method of bonsai and overshadowing in which there were 5 light levels, a total of 40 treatments to research the growth and saponin production of D. Zingiberensis variety 'Anjiang 3'which living in different light conditions, with the purpose of finding the most appropriate light environment and providing science and technology bases for cultivation of Dioscorea zingiberensis.A main objective of this research was to make the intensively study about growth,morphogenesis,physiological character and secondary metabolites production etc.of the D. Zingiberensis variety 'Anjiang 3', discussing which kind of light intensity made the best group growth and the most saponins yuan yield, the final intent was to achieve the farming management of D. Zingiberensis variety 'Anjiang 3'in order to alleviate the saponins yuan resources crisis which needed by medicine industry.The main results were as follows:1 Variance Analysis showed that there was significant difference between the reproductive period of the Dioscorea zingiberensis which living in different light intensity, and proved that shadow made the reproductive period lated.The order of seedlings and anthesis were:100% of natural light,80% of natural light,60% of natural light,40% of natural light.20% of natural light。Indicated that highlight spurred the reproductive period come early.2 Variance Analysis showed that there were significant difference between the leaf number and stem length of the Dioscorea zingiberensis which living in different light intensity(P<0.05), while the situations of branch number and stalk circumference were opposite(P>0.05).The results showed that the shortest seedling were the plants which living in natural and 20% of natural light, however the highest was the plant which living in moderate light, all of these proved that strong light can restrain the expanded growth of the seedling, and weak light cannot provide enough energy for vegetative growth of the seedling, while the moderate light can provide the best environment for the seedlings growth;With the light intensity attenuated, the leaf number was presented openings downward parabolic trend, and the seedling plants living in 60% of natural light got the most leaves, which proved that the moderate light make the seedling growth fastest;The seedling which were living in 40% and 60% of natural light had the most branch number, this suggested that shadow increased the branch number, by contrastly, the strong light restrained it; With the light intensity attenuated,the stalkcir cumference was presented openings upward parabolic trend, and the stalk circumference of seedling plants living in 80% and 100% of natural light were the largest, which illustrated that strong light promote the stem horizontal growth and promote the assimilate in support structure increased.3 Variance analysis showed that there were significant difference between many leaf characteristics of the Dioscorea zingiberensis which living in different light intensity(P<0.05). Leaf mass,Leaf area,mass per area,Leaf length,Leaf width and Chlorophyll content were all presented openings upward parabolic trend, while the variation tendency of water content and Leaf thickness were complex.4 Variance analysis showed that there were significant difference between the activity of catalase(CAT) and the content of malondialdehvde(MDA) in leaves of the Dioscorea zingiberensis which living in different light intensity, while there were no significant difference between the activity of peroxidase(POD) in leaves. With the light intensity attenuated, the activity of CAT was overall an downward trend, which proved that strong light could enhance the resistance;The content of MDA in leaf of 100% of natural light was far more than any other groups, which illustrated that strong light made against the growth of plant;the activity of POD was roughly presented openings upward parabolic trend, and the POD activity of 60% natural light was the lowest, all of which were proved that the 60% natural light environment is best for the Dioscorea zingiberensis growth.5 Variance analysis showed that there were significant difference between the content of starch and soluble sugar in leaves of the Dioscorea zingiberensis which living in different light intensity.The plants which living in the 60% of natural light had the most starch, but the plants living in 20% of natural light had the opposited situation, which illustrated that the plants living in moderate light had the best photosynthesis, and the leaf contained a mass of photosynthesis production;The plants which living in the 40% of natural light had the least soluble sugar, while there were a dramatic increase in the 20% of natural light.Analysis showed that the most photosynthesis production of the plant living in moderate light was assigned to root, however the most photosynthesis production was provided to the ground part growth which living in strong light.Therefore, the plant living in 20% of natural light had the most soluble sugar.6 Variance analysis showed that there were significant differences between every root characteristics of the Dioscorea zingiberensis which living in different light intensity. With the light intensity attenuated, the fresh root mass and the root diosgenin content were all presented openings downward parabolic trend;the fibrous root length was presented a shorter tendency;the number of shoot was presented a W shape tendency.On the whole, moderate light took the best environment for the root growth and made the most saponin content. |
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