Abstract: In order to dentification and screening of hybrid of salinity sunflower and mechanism studying of salt tolerance.The salinity of 25 sunflower hybrids were identified and evaluated using groups gradually classification,and two very strong salt resistance hybrids named Neikuaiza No.4 and p65 and four strong salinity hybrids were screened out.In the fields and indoor potted environment,sunflower salinity mechanism and evaluation techniques were researched under different concentrations of salinity stress.The results showed that salt stress made leaf area,chlorophyll content and net photosynthetic rate of seedling sunflower decreased,and the greatest impact on net photosynthetic rate was transpiration rate(Tr) under low salt,followed by water use efficiency;the rank of the influence extent of impact on net photosynthetic rate were water use efficiency,transpiration rate and intercellular CO2 concentration under the medium salt;and the greatest impact on net photosynthetic rate was water use efficiency under severe salt,following was transpiration rate(Tr);non-stomatal factor was the dominant factor limiting the net photosynthetic rate under salt stress;free proline,soluble sugar and soluble protein content increased with the composite salt concentration increases,this osmotic adjustment mechanism also played an important role in sunflower salt tolerance.Salt-tolerance evaluation of two hybrids and three inbred line parents showed that,compared to the parental inbred lines K55,K58,K59 the hybrid K55×K58,K55×K59 showed certain heterosis and transgressive heterosis and on soluble sugar,soluble protein and free proline content and growth rate and chlorophyll content,leaf area,net photosynthetic rate and other indicators.

Key words: Saline tolerance, Sunflower, Hybrid, Mechanism, Heterosis

CLC Number: 

• S565.5