Effects Of Salt Stress On Germination And Seedling Growth Of Rice Restorer Line

Soil salinization and alkalization is one of the major limiting factors affecting the production of rice, which is salt-sensitive. With the unusual environmental variations and irrational irrigations, salinization and alkalization exist in at least one fifth of arable land in the world with varying degrees. In China, the salinization and alkalization land were nearly 1×108 hm2, and 1733×104 hm2 were under potential salinization and alkalization. Taizhou region has long been the land reclamation as the primary means to increase grain planting area, but due to the high salt content of the soil and lack of varieties or combinations of salt-tolerant rice, the rice yield is generally low. So, it is very important to breed salt tolerance rice varieties or combinations suitable planting in Taizhou area. In this study, we measured the significance of difference and correlation of the tested indexes in the bud and seeding stages of the restorer line in order to screen out the salt-tolerant lines, which is helpful in rice breeding and cultivation for salt resistance.In this study, nine different rice restorer lines FL478, ST500, ST1040, ST1050, ST940, ST1054, D159,9311 and Y292 were selected for salt stress tolerance, with the salt-tolerant varieties FL478 from the International Rice Research Institute as control. All these varieties were treated with NaCl solutions at the concentration levels of 0,0.4%,0.6%,0.8% and 1.0% in the bud and seeding stages. At the germination stage, the germination energy, germination percentage, germination index, vigor index, relative salt damage rate were measured, while the seed growth status and the growth status, proline content, reducing sugar content and the ratio of sodium and potassium ions in the root system were measured at the seedling stage.The results showed that:in the bud stage, with the increase of NaCl concentration, the inhibition extent of seed germination of each restorer line were significantly enhanced; the salt tolerance among the selected varieties differed greatly, with high salt-tolerance of ST1040, ST1050, medium salt-tolerance of ST940 and D159 and weak salt-tolerance of 9311 and ST500. At the seedling stage, NaCl concentration significantly affected the indexes, among which the proline content, total sugar content, the ratio of sodium and potassium ions in the root system rised with the increased NaCl concentration. The salt tolerance capacity of each restorer line differed between the germination and seedling stages, and no significant correlation was observed between them.