Abstract: In order to study the effects of NaCl stress with different concentrations on physiological characteristics and gene expression of TaNHX1,two new wheat varieties (Luyuan 502 and Qingmai No.6)were used as the experimental materials.Physiological indexes of seeds germination rate,seedlings fresh weight,roots vigor,plasmalemma permeability,MDA content and Na⁺ content of the two wheat varieties were determined under above 100 mmol/L NaCl stress of 50,100,150 and 200 mmol/L,and compared the relative expression of tolerant gene TaNHX1 in roots and stem base of wheat through RT-qPCR method.The results showed that the seeds germination rate of Qingmai No.6 was more than that of Luyuan 502 under above 100 mmol/L NaCl stress.Low concentration NaCl stress had significant promoting effect on seedlings growth of Qingmai No.6,and the seedlings fresh weight of Qingmai No.6 significantly decreased under NaCl stress of 150 mmol/L,while that of Luyuan 502 began to decreased significantly under NaCl stress of 100 mmol/L.The roots vigor of Luyuan 502 decreased significantly more than that of Qingmai No.6 under high concentration NaCl stress.Under the same concentration NaCl stress,the leaf plasmalemma permeability and MDA content of Luyuan 502 were significantly more than that of Qingmai No.6,it indicated that NaCl stress had less damage on leaf cell membrane of Qingmai No.6.Na⁺ content of roots and stem base of Qingmai No.6 were all significantly more than that of Luyuan 502 under high concentration NaCl stress,it indicated that Na⁺ exclusion capability of roots and stem base of Qingmai No.6 was significantly more than that of Luyuan 502,which could effectively restrict Na⁺ transporting to shoot.The TaNHX1 gene of Luyuan 502 and Qingmai No.6 respectively reached the highest expression level under NaCl stress of 100,150 mmol/L.It indicated that Qingmai No.6 is more salt tolerant than Luyuan 502,and the maximum concentration of salt tolerance of Luyuan 502 is 100 mmol/L,while that of Qingmai No.6 is 150 mmol/L.

Key words: Wheat, Germination rate, Physiological characteristics, Na⁺ content, Relative TaNHX1 expression, Salt tolerance

CLC Number: 

• Q945.78

• S512.01