Studies On The Characters Of Carbon & Nitrogen Metabolism Of Resistance (Tolerance) To Rhizomania In Sugarbeet

Rhizomania in Sugarbeet is a disease in the world, which have reduced the yield of sugarbeet and sugar. So it's very important to illuminate the principle of resistance to Rhizomania in sugarbeet. The research studied the relationship between physiology index of carbon & nitrogen metabolism and the Rhizomania in sugarbeet with the method of comparative physiology. The results showed: (1) During the prometaphase of growth,the nitrite contents, activity of nitrate reductase(NR) and the total amino acid contents of susceptible varieties in diseased soil were higher than the resistant ones. But the resistant varieties were higher contents of soluble sugar than the susceptible ones. Therefore, reducing the intensity of nitrogen metabolism and stabilizing the level of Carbon Metabolism is useful for resisting Rhizomania in Sugarbeet. (2)The nitrite contents, activity of nitrate reductase (NR), the total amino acid contents, soluble protein and soluble sugar in diseased soil were lower than th-ose in non-diseased soil.Infection of pathogenic bacterium could reduce the intensity of carbon & nitrogen metabolism ,which decreased sugar contents and beet yield finally.(3) There were significant differences in the contents of soluble protein and activity of nitrate reductase(NR) of leaves between the susceptible varieties and the resistant varieties during leaves quickly growing phase. The contents of soluble sugar in leaves also had evident differences between different varieties during sugar contents increasing phase. So these indexes could be used in resistant to Rhizomania in sugarbeet. These results provided the theoretics basis for selective breeding and prev-ending in resistance to Rhizomania in sugarbeet.