Study On Root Morphological Characters In Sugar Beet With Low Phosphorus Stress

In the world, 1.319 billion hectares cultivated land is short of phosphorus, two-thirds cultivated land of china is short of phosphorus. Phosphate is easy fixed for its chemical character, and fixation phosphate is difficult to be absorbed by plant. Only depending on manufacturing and using phosphate fertilizer hardly solve the lack of phosphorus in soil, so it is a good way to solve the problem by selecting the resist low phosphorus stress variety. In this experiment, we study on root morphology, anatomy characters using No. 20 (high resistance), No. 17 (middle resistance), and No. 14 (low resistance) by screening different resistance of sugar beet varieties to low phosphorus stress, the results are following:1,When sugar beet is under condition of low phosphorus stress, not all the root systems of the varieties are restricted, fresh root weight of high resistant varieties to low phosphorus stress is added.2,The growth of above-ground part is restricted at first, the root system influenced is relatively smaller, so R/C appears increasing, increasing above 50% , but levels increased are not connect with resistant ability to low inorganic phosphorus stress.3,The total length of root hair is corresponding with the resistant ability to low phosphorus stress, variety 20 is the longest, variety 17 is middle, and variety 14 is the shortest.4,The result tendency of liquid culture is conformity with that of sand culture, in the condition of phosphorus stress, the length of root system, the root radius and the root surface are influenced differently, the variety of middle resistance to low phosphorus stress, No. 17 is influenced least.5,The density of cortex cell is added in different extent, the No. 20 is the largest, the No. 14 is in the middle, and the No. 17 is the smallest. The thickness of cortex become thinner, No. 14 is thinned most, the varieties of higher resistance to low phosphorus is smaller.6,The degree of tissue differentiation is increased, the level of increased is corresponding with the ability of resistance to low phosphorus stress, variety No. 20 increases about 7.8%, variety No. 17 increases 5%, and variety No. 14 decreases 7.6% than they are under the condition of enough phosphorus.