盐度已成为农业用地的主要环境问题,导致作物产量下降。因此,植物生物学专家旨在通过深入研究盐胁迫的影响以及大麦对盐胁迫的反应,从基因上改善大麦对盐胁迫的适应性。在这种情况下,本研究旨在探讨抽穗期5种突尼斯春大麦基因型对盐胁迫的生理生化反应变化。通过在灌溉水中使用100mMNaCl(T1)和250mMNaCl(T2)诱导两种盐度处理。在响应盐胁迫的基因型中检测到显着的表型变异。暴露于250mMNaCl的植物在所有研究的生理参数中显示出重要的下降,即,气体交换,离子浓度和相对含水量RWC。观察到的浓度下降范围为,大约,K+为6.64%至40.76%,Na+为5.91%至43.67%,Ca2+为14.12%至52.38%,在不同基因型和盐胁迫水平下,Mg2+为15.22%至38.48%。然而,在盐度条件下,所有基因型的脯氨酸和可溶性糖增加,脯氨酸浓度平均增加1.6倍,可溶性糖浓度平均增加1.4倍。此外,所有基因型的MDA水平也上升,Lemsi基因型的增幅最大(与对照组相比增加了114.27%)。在所有处理中,与其他基因型相比,Ardhaoui和Rihane显示出更高的光合活性。逐步回归方法确定了钾含量,K+/Na+比值,相对含水量,气孔导度和SPAD测量为千粒重的主要性状(R2=84.06),表明它们在缓解大麦盐胁迫中的重要作用。总的来说,在航向阶段,盐水灌溉土壤中的盐分积累通过影响气体交换参数来显着影响大麦的生长,矿物成分和水含量,以基因型依赖的方式。这些结果将有助于阐明这些变异的遗传机制,以促进大麦对盐胁迫的耐受性的靶向改善。
Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve barley\'s adaptation to salinity stress by deeply studying the effects of salt stress and the responses of barley to this stress. In this context, our study aims to explore the variation in physiological and biochemical responses of five Tunisian spring barley genotypes to salt stress during the heading phase. Two salinity treatments were induced by using 100 mM NaCl (T1) and 250 mM NaCl (T2) in the irrigation
water. Significant phenotypic variations were detected among the genotypes in response to salt stress. Plants exposed to 250 mM of NaCl showed an important decline in all studied physiological parameters namely, gas exchange, ions concentration and relative
water content RWC. The observed decreases in concentrations ranged from, approximately, 6.64% to 40.76% for K+, 5.91% to 43.67% for Na+, 14.12% to 52.38% for Ca2+, and 15.22% to 38.48% for Mg2+ across the different genotypes and salt stress levels. However, under salinity conditions, proline and soluble sugars increased for all genotypes with an average increase of 1.6 times in proline concentrations and 1.4 times in soluble sugars concentration. Furthermore, MDA levels rose also for all genotypes, with the biggest rise in Lemsi genotype (114.27% of increase compared to control). Ardhaoui and Rihane showed higher photosynthetic activity compared to the other genotypes across all treatments. The stepwise regression approach identified potassium content, K+/Na+ ratio, relative
water content, stomatal conductance and SPAD measurement as predominant traits for thousand kernel weight (R2 = 84.06), suggesting their significant role in alleviating salt stress in barley. Overall, at heading stage, salt accumulation in irrigated soils with saline
water significantly influences the growth of barley by influencing gas exchange parameters, mineral composition and
water content, in a genotype-dependent manner. These results will serve on elucidating the genetic mechanisms underlying these variations to facilitate targeted improvements in barley\'s tolerance to salt stress.