摘要： 为了研究不同浓度NaCl胁迫对小麦生理特性及TaNHX1基因表达的影响，以鲁原502和青麦6号2个小麦新品种为试验材料，50，100，150，200 mmol/L NaCl胁迫下测定2个小麦品种种子发芽率、幼苗鲜质量、根系活力、质膜透性、MDA含量、Na⁺含量等生理指标，并通过荧光定量PCR方法对小麦耐盐基因TaNHX1在根部和茎基部的表达量进行了比较。结果表明，100 mmol/L以上浓度NaCl胁迫下青麦6号种子发芽率显著高于鲁原502；低浓度NaCl胁迫对青麦6号幼苗生长具有显著促进效应，150 mmol/L NaCl胁迫下青麦6号幼苗鲜质量显著降低，而鲁原502幼苗鲜质量在100 mmol/L NaCl胁迫下就开始显著降低；高浓度NaCl胁迫下鲁原502根系活力下降幅度显著大于青麦6号；相同浓度NaCl胁迫下鲁原502叶片质膜透性和MDA含量均显著高于青麦6号，说明NaCl胁迫对青麦6号叶片细胞质膜伤害较小；高浓度NaCl胁迫下青麦6号根部和茎基部Na⁺含量均显著高于鲁原502，说明青麦6号根部和茎基部的拒Na⁺能力显著大于鲁原502，可以有效限制Na⁺向地上部运输；鲁原502和青麦6号的TaNHX1基因分别在100，150 mmol/L NaCl胁迫下达到最高表达量。以上结果说明青麦6号比鲁原502更耐盐，鲁原502的最高耐盐浓度为100 mmol/L，青麦6号的最高耐盐浓度为150 mmol/L。

关键词: 小麦, 发芽率, 生理特性, Na⁺含量, TaNHX1表达量, 耐盐性

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

中图分类号: 

• Q945.78

• S512.01