| Abstract: | Through a pot experiment, 4 Brassica rapa cultivars, Lonyou 6, Longyou 7, Tianyou 2 and Tianyou 4, with different drought resistance, were used as materials to measure the effects of drought stress on the main agronomic characters and physiological and biochemical indexes under the condition of simulated dry environment with artificial control of water. The results show that with the prolongation of the drought stress time the seedling leaf chlorophyll concentration of 4 Brassica rapa cultivars had a trend of increasing first and then decreasing, while relative electric conductivity increased, the taproot length, lateral root number, root dry weight and root cap ratio rose, and root activity decreased. After drought stress, Longan 7, with strong drought resistance, possessed long main root, more lateral roots, heavier root dry weight, larger root crown and stable root viability. Tianyou 2, with weak drought resistance, possessed shorter main root, less lateral roots , lighter root dry weight, smaller root crown, and the root activity varied greatly. The corresponding indexes of Lonyou 6 and Tianyou 4 were between Longyou 7 and Tianyou 2 . |
