盐胁迫对四种基因型冬小麦幼苗Na^+、K^+吸收和累积的影响

Effects of salt stress on the absorption and accumulation of Na^+ and K^+ in seedlings of four winter wheat (Tritium aestivum) genotypes

以4种不同基因型冬小麦品种为试验材料,研究了盐胁迫下小麦幼苗的生长及Na+、K+和Cl-的吸收、累积规律。结果表明,盐胁迫下小麦吸水困难,幼苗生长受抑;幼苗含水量、生物量及干物质量明显下降;Na+、Cl-含量和单株累积量显著增加,K+含量和单株累积量则明显降低。Na+/K+比值随介质中的盐浓度的增加而升高。盐胁迫下各基因型冬小麦幼苗Na+、K+和Cl-的单株累积量及其在地上部分和根系中的含量变化较大,说明小麦根系对Na+、K+和Cl-的吸收存在基因型差异。盐处理下,暖型小麦NR9405对K+的选择吸收能力强,对Na+的吸收和累积少,植株体内的K+浓度较高,Na+/K+比值小;幼苗的生物量较大,耐盐性强。冷型小麦RB6对K+的选择能力差,对Na+的吸收和累积量大,幼苗的Na+/K+比值大,生物量小,耐盐性较差。低盐浓度下,Na+可作为渗透调节物质维持植物体内渗透平衡。高盐浓度下,Na+的过度吸收和累积可能是盐害的主要原因。维持体内较低的Na+水平和Na+/K+比值是小麦耐盐性的一个重要特征。

This research investi winter wheat genotypes under concentration and accumulation gated the growth response and Na ^＋ and K ^＋ absorption and accumulation in seedlings of four salt stress. The results showed that the water content, biomass, dry weight, and K^＋ of the seedlings decreased greatly under salt stress. In contrast, the concentration and accumulation of Na^＋ and Cl^- in the seedlings increased concentration increased in the growth medium. There were The Na^＋/K^＋ ratio in the seedlings increased as the salt differences in the concentration and accumulation of Na ^＋ and Cl^- among the wheat genotypes, which indicated that wheat roots had genotypic differences in total on 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 adjust the osmosis potential and maintain the osmosis balance under low NaCl concentration. Excessive Na^＋ osmotica and 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.