Identification And Selection Of Salt Resistant Sunflower Varieties

With the situation that the salinization of soil is serious and that that the sunflower varieties are chaotic and miscellaneous, based on the extensive collection of sunflowers in different forms and various physiological genotypes, the gradients of water and salt were set. Under the conditions of indoors, filed and pot, the new variety of sunflower for salt ressistance and water saving was selected by camparing the differences of the germination, seedling, filed growth, photosynthetic characteristics, material accumulation, water use and yield. The results showed that:Salt stress not only had a significantly inhibitory effect to the germination of sunflower, but also to the plant height, leaf area, plant dry weight, chlorophyll content and photosynthetic rate. With the increase of salt stress concentration, the forms and the photosynthetic index of sunflower showed a downward trend. And the differences between varieties increased significantly. The salt stress made the cell membrane permeability, malondialdehyde (MDA) and proline content increased in leaves of flowers. Through cluster analysis, eight varities of sunflower with strong salt ressistance were screening out. They were NTC90, AD6199, NTC99, C8368, SD998, SD997, T33 and Xianrui 9. Under moderate salt stress (0.6mol/L concentration), their common features are:(1) the germination was fast and the rate of germination and emergence reached more than 50%; (2) the higher the plant height was, the bigger the leaf area,the heavier the shoot dry weight arid the fast the root grew; (3) both chlorophyll content and photosynthetic rates were higher; (4) the content of malondialdehyde (MDA) and membrane permeability had a relatively low value, while the proline content was high and the ability of the osmotic adjustment was strong.Field test results show that, the leaf area index, dry matter accumulation, photosynthetic performance index, water use efficiency and the economic yield of AD6199 and NTC90 were significantly higher than those of the other varieties, with good salt ressistance, water-saving and high performance, suitable for large-scale planting in the Hetao irrigation District.