Abstract:

In order to select out the quinoa varieties with strong salt tolerance and provide reference for the identification of salt tolerance at seedling stage, three different quinoa varieties were used as experiment materials. The relative growth indexes were determined by measurement, the chlorophyll content was determined by ultraviolet spectrophotometer, the relative ion permeability was determined by conductance method, and the relative expression of salt-tolerant gene CqNHX1 was compared by real-time quantitative PCR under salt stress. The results showed that the plant height of SQ1 was decreased slightly, the biomass was increased, the relative ion permeability remained almost unchanged, and the expression levels of CqNHX1a and CqNHX1b were both significantly increased under salt stress, indicating that SQ1 could grow normally under a high salt environment. Compared with the control, the plant height and chlorophyll content of SQ34 was significantly decreased, the biomass remained unchanged, while the expression levels of CqNHX1a and CqNHX1b were significantly increased. The root-shoot ratio and chlorophyll content of QQ61 were significantly decreased under salt stress, while the relative ion permeability was significantly increased, and the expressions of CqNHX1a and CqNHX1b were down-regulated, demonstrating that the salt tolerance of this variety was weak. Salt tolerance between different quinoa varieties differed remarkably, the rank was: SQ1 > SQ34> QQ61. SQ1, as a high salt tolerant variety, can be further popularized in saline-alkali land.

Key words: quinoa, salt stress, seedling growth, CqNHX1 gene expression, salt tolerance