Physiological Characteristics Of Resistant (Tolerant) Or Sensitive Sugarbeet-Variety To Rhizomania And Their Relation To Potassium Nutrition

Some physiological characteristics of resistant(tolerant)or sensitive sugarbeet-variety to Rhizomania and their relation to potassium nutrition were studied.The results showed : (1) With the development of growth, metabolism of Potassium ,Nitrogen and Sodium became weak gradually .Resistant variety had active metabolism during the prophase of growth,and Potassium fertilizer could enhance it and increase the proportion of potassium and sodium in the root of sugarbeet, and weaken the metabolism of Sodium during the late phase of growth;(2) Potassium fertilizer could strengthen the activity of root ,which was higher in the root of sensitive variety than the other during the prophase of growth,but it was reverse in the late phase of growth;(3) Potassium fertilizer could enhance the activity of Peroxidase for both variety, which in resistant variety was superior to in the other;(4) Potassium fertilizer could reduce the content of Ethylene of the root, which was higher in the root of sensitive variety than in the other.(5)Sensitive variety was able to maintain higher speed of pure photosynthesis than the other in the condition of the strong light,and Potassium fertilizer could improve it, but it was reverse under the weak light. To some extent the study had provided the theoretical basis and the referenced value for physiologically selecting and breeding a new sugarbeet-variety to Rhizomania and control of Rhizomania in sugarbeet.