| This study based on the experiments of the mulberry seedlings of Fengchi,Yu 71-1 and Zhongsang 973 under salt-stress,and we determined the processing conditions of mulberry salt resistance research and the physiological indexes to evaluate the salt resistance of mulberry in the next experiment,based on the analysis of the osmotic regulative substances contents and antioxidant enzyme activity;Then,the salt tolerance of Yu71-1,Jin10 and Da10 was evaluated by the analysis of the salinity tolerance of the leaves from this three practical mulberry cultivars.Finally,the salt resistance of the three mulberry varieties was evaluated by the analysis of the osmotic regulative substances contents and antioxidant enzyme activity of green branch cuttings plant seedlings of the three mulberry varieties.The main results and conclusion were as follows:1.Different varieties of mulberry in vitro leaves showed obvious yellowing symptoms when the round leaves of the 300 mM NaCl solution treatment group were treated with 2 days.The concentration of 300 mM NaCl solution and the processing time of 2 days can be the conditions of salt stress in comparing different mulberry varieties in vitro leaf,to make preliminary speculation of salt tolerance of different mulberry varieties.2.The osmotic regulative substances contents and antioxidant enzyme activity of Fengchi mulberry,Yu 71-1 and Zhongsang 973 under salt stress treatment showed significant differences compared with control group.Moreover,different indexes showed different trends under different salt stress treatment conditions.The osmotic regulative substances contents and antioxidant enzyme activity of mulberry were closely related to salt stress.The differences of these physiological indexes can be used as the basis for the analysis and evaluation of the salt resistance of different mulberry varieties.3.The results show that 300 mM NaCl solution was a significant effect of stress on fengchi mulberry on the treatment of 3 days,when salt stress was treated with salt-denslty gradient.When adopted salt stress processing time gradient in the mulberry seedlings of Yu71-1 and Zhongsang 973 to salt stress processing,the results show that processing 7 days in the mulberry seedlings of Yu71-1 and Zhongsang 973 with 300 mM NaCl solution have obvious salt-stress effect.Therefore,the salt concentration of 300 mM and the treatment time of 7 days can be used as the treatment conditions in the study of salt stress in mulberry tree.4.According to the loss of green coloration under salt stress in the leaf of these three practical mulberry varieties,the preliminary evaluation of the salt tolerance from highest to lowest among the three varieties is Da 10,Jin 10,Yu 71-1.Green branch cuttings plant seedlings in pot of the three practical mulberry varieties Yu 71-1,Jin 10,Da 10 were treated with 300mmol/L NaCl and the content of osmotic regulative substances and antioxidant enzyme activity in roots,bark,leaves were measured.Found that the content of osmotic regulative substances and antioxidant enzyme activity in roots and leaves of Da 10 were more steady under salt stress,the content of osmotic regulative substances and antioxidant enzyme activity were increased in Yu71-1.These results suggest that the salt tolerance from highest to lowest among the three varieties is Da 10,Jin 10,Yu 71-1.This study provides some reference value for the study of salinity tolerance of mulberry trees,through the salt stress experiments of mulberry seedlings and cutting seedlings. |
