不同品种花生耐盐性及Na~+吸收动力学特性

为了探究不同品种花生(花育20、花育25和花育36)幼苗的Na~+吸收动力学特性与耐盐性的关系,采用水培试验,研究了不同盐胁迫浓度下,不同花生品种幼苗的干物质积累变化、Na~+吸收动力学特性、Na~+吸收速率、Na~+排斥率与其耐盐性的关系。结果表明:花生对Na~+的吸收可分为高亲和、低亲和2个吸收阶段。低盐胁迫下,花生的Na~+亲和力常数(K_m)小,选择性强,Na~+排斥率平均值在85%左右;在高盐胁迫环境下为低亲和系统,K_m值大,Na~+最大吸收速率(V_(max))大,同时其排斥率较低。低盐胁迫下,花育20、花育25和花育36对Na~+的吸收速率较小,排斥率较高,Na~+积累慢,盐害轻;高盐胁迫下,花育20的Na~+吸收速率高于花育25和花育36,而Na~+排斥率低于花育25和花育36。因此高盐胁迫下,较高的Na~+吸收速率和较低的Na~+排斥率可能是花育20耐盐性弱于花育25和花育36的主要原因。

Salt Tolerance of Different Peanut Varieties and Na+ Uptake Dynamic Characteristics

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.