Effects of salt stress on the absorption and accumulation of Na+ and K+ in seedlings of four winter wheat (Tritium aestivum) genotypes
盐胁迫对四种基因型冬小麦幼苗Na+、K+吸收和累积的影响

This research investigated the growth response and Na + and K + absorption and accumulation in seedlings of four winter wheat genotypes under salt stress. The results showed that the water content, biomass, dry weight, and K + concentration and accumulation of the seedlings decreased greatly under salt stress. In contrast, the concentration and accumulation of Na + and Cl - in the seedlings increased. The Na + /K + ratio in the seedlings increased as the salt concentration increased in the growth medium. There were differences in the concentration and accumulation of Na + and Cl - among the wheat genotypes, which indicated that wheat roots had genotypic differences in total absorption of Na + , K + and Cl - . Genotype NR9405 has a higher canopy temperature compared to the other genotypes. Under salt stress, it had a higher capacity for selective K + uptake and lower Na + uptake and translocation compared to the other genotypes. As a result, it had a higher cytosolic K + concentration and a lower Na + /K + ratio. It also had greater biomass production compared to the other genotypes. In contrast, genotype RB6 has a relatively low canopy temperature. Our results indicated that it had a lower capacity for K + uptake and a higher capacity for Na + accumulation compared to the other genotypes. This resulted in a higher Na + /K + ratio and lower biomass production. Na + entering the plant could function as an osmotica and adjust the osmosis potential and maintain the osmosis balance under low NaCl concentration. Excessive Na+ absorption is one of the main causes of plant injury and a reduction in growth under high salt stress. The ability to maintain a low cytosolic Na~+ concentration and a small Na~+/K~+ ratio could be a major characteristic of salt tolerance in wheat.