ZHANG Yanfang, SUN Ruifen, GUO Shuchun, HOU Jianhua
5 oil sunflower hybrids, P6, P29, P65, S13 and P50, are used to study the plant morphologies of the soil culture at 3 different concentrations of NaCl, 300, 350 and 400 mmol/L, and the plant morphologies of the water culture at 3 different concentrations of NaCl, 100, 120 and 150 mmol/L. The tolerance to the salt stress is identified for the water culture with 9 day's treatment of 120 mmol/L NaCl. Five physiological and biochemical indexes, including the soluble protein content, the Pro content, the MDA content, the SOD activity, and the POD activity about the salt-tolerance of water cultures of P50 and P29 are determined by two treatments of 120 and 150 mmol/L concentrations of NaCl, to investigate the different responses to the salt stress among oil sunflower hybrids. Results show:1) The salt tolerance capacities of five oil sunflower hybrids are in the following order:P50> P65> P6> S13> P29. With respect to the degree of salt tolerance, P50 and P65 are very strong salt-tolerant types, S13 and P6 are moderate salt-tolerant types, P29 is a very weak salt-tolerant type. 2) Five indexes show a very significant difference between P50 and P29. 3) Five indexes show very significant difference by comparing with different concentrations of the same species of P29 and P50. P50 shows a strong resistance to the salt stress.
