关键词: 花生, 盐胁迫, 动力学, Na+吸收, 干物质积累速率

Abstract: In order to explore the relationship between Na+ uptake dynamics and salt tolerance in different peanut varieties (HY20, HY25 and HY36) , this paper carried out hydroponic experiments to investigate the relationship between dry matter accumulation, Na+ uptake dynamics, Na+ absorption rate, Na+ rejection rate and salt tolerance of different peanut seedlings under different salt stress concentrations. The results showed that Na+ uptake dynamics in peanut could be divided into 2 absorption phases: high affinity and low affinity. Under low salt stress, peanut Na+ affinity constant (Km) was small, and the mean value of Na+ exclusion rate was about 85%. Under high-salt stress environment, the Km value and Na+ maximum absorption rate (Vmax) was large, and Na+ rejection rate was low. Under low salt stress, the absorption rates of Na+ in HY20, HY25 and HY36 were all small, while Na+ exclusion rate was high with slow Na+ accumulation, so the salt stress was less harmful. Under high salt stress, the Na+ absorption rate of HY20 was higher than that of HY25 and HY36. But the Na+ exclusion rate in HY20 was lower than that in HY25 and HY36. Therefore, under high salt stress, high Na+ absorption rate and lower Na+ exclusion rate might be the main reason for the salt tolerance in HY20 was weaker than that of HY25 and HY36.

Key words: peanuts, salt stress, dynamics, Na+ uptake, rate of dry matter accumulation