The Effects Of NaCl Stress On Seed Germination And Physiological And Biochcmcial Traits Of Barley Seedling

Barley have stronger ability to resisting salinity and it can be used as preferred crop on alkali land. Thus, it is very important to understand the mechanism of salinity tolerance for exploiting alkali land. 34 barley cultivars treated with different NaCl concentration during germination stage and seedling stage were chosen to study the physiological and biochemical reaction under the salt stress and to evaluate the salinity resistance of these cultivars in this paper. The main results are as follows.1. Sampson was treated with different NaCl concentration to study the effect of NaCl concentration on germination ability during germination stage. The results showed that lower concentration (<0.4%NaCl) promoted the germination and higher concentration (>0.4%NaCl) restrained the germination. Germination process was delayed.Germination index and vitality index decreased as NaCl concentration increased.2. The barley seedling was treated with different NaCl concentration. The result showed that the growth of barley seedling was significantly restrained with the increase of the NaCl concentration. The chlorophyll content increased and then decreased with the increase of the NaCl concentration. The change of the superoxide dismutase activity had a typical'V'shape with the increase of the NaCl concentration. The membrane permeability and the malondialdehyde content increased with the increase of the NaCl concentration.3. The effect of NaCl stress on germination of 34 barley cultivars were studied in this paper. The results showed that the inhibitive effect of NaCl on seed germination obviously increased with the increase of the NaCl concentration. 34 barley cultivars tested have different salinity tolerance ability. Among the 34 barley cultivars, Dabo30 and ND11231-11 were salt tolerant whereas Hongripimai 2 and Alex and Dabo37 and Stirling were not salt tolerant. The other cultivars were moderately salt tolerant.4. The growth of each cultivar was obviously restrained compared to the check as the NaCl concentration increased. The chlorophyll content decreased while the superoxide dismutase activities increased with the increase of the NaCl concentration. The malondialdehyde content increased gradually. Every parameter varied with cultivars, so the salinity resistant ability of each cultivar can be classified by these parameters.5. The degree of sensitivity to salt stress in different barley cultivars differed during germination stage and seedling stage. ND11231-11 and Dabo30 have higher ability to resisting salt stress during germination stage whereas Poland and Nista as well as Morrison have higher ability to resisting salt stress during seedling stage. According to the synthetic evaluation of the physiological parameters during germination stage and seedling stage, the order of the ability to resisting salt stress is as follows: Poland, Lima, ND4994·16, Dabo30>Dabo35>13297, Abee>Dabo32, XinyinD5, Nista>Celink, Harringston, Morrison, Dabo33>Dabo31>Bonous, Crystal, ND11231-11, XinyinD6, Dabo36>Dabo28, Dabo38, XinyinD3>Jersery, SD89-22, Dabo37>Bank, XinyinD7, Dabo34>Hongripimai2>Stiring, Ganpi2>Alex.