4种燕麦对NaCl胁迫的生理响应及耐盐性评价

为研究4份燕麦坝莜一号、白燕2号、白燕6号和白燕7号的耐盐程度及其在盐胁迫处理下的生理反应规律,在水培条件下,分别用0,34.2,68.4,102.6,136.8,171.0 mmol/L浓度NaCl溶液模拟盐胁迫处理4种燕麦种子,观察记录各处理的盐害情况,分别测定了胁迫后的种子发芽势、发芽率、株高和根长,以及室温培养的燕麦幼苗叶片过氧化物酶(POD)、超氧化物歧化酶(SOD)和可溶性蛋白含量,分析了不同胁迫程度下各生理指标的变化情况,并且对4种燕麦的耐盐性进行了综合评价。结果表明,NaCl胁迫对4种燕麦种子的发芽势和发芽率均产生显著影响,对株高和根长产生了抑制作用,且均随盐浓度的增大呈逐渐降低的趋势;燕麦幼苗叶片POD活性、SOD活性、可溶性蛋白含量均在102.6 mmol/L 盐浓度下达到最大值,而且都随盐浓度的增大呈先升高后降低的趋势,表明燕麦具有较高的耐盐能力,在盐胁迫下可采取自我保护机制以适应盐胁迫,4种燕麦的耐盐阈值为102.6 mmol/L盐浓度。综合评价,白燕6号耐盐性较好,白燕2号具有高盐耐受性的潜力,这两个燕麦品种可以为耐盐基因挖掘及燕麦耐盐品种的选育提供材料。

Physiological responses and tolerance of four oat varieties to salt stress

This paper reports on a study of the adaptability of oats (Avena sativa) to salt stress. In a hydroponic experiment, the physiological responses of four oat varieties (Bayou-1, Baiyan-2, Baiyan-6 and Baiyan-7) were investigated using six concentrations (0, 34.2, 68.4, 102.6, 136.8 and 171.0 mmol/L) of sodium chloride during seed germination and seedling stages. Seed germinating potential, germinating percentage, seedling height and root length were recorded. The activities of superoxide dismutase (SOD), peroxidase (POD) and the soluble protein content in the leaves of seedlings were also measured. Salt stress had a significant impact on germinating potential and percentage. It also suppressed seedling height and root length. All four parameters decreased with increases in Na⁺ concentration. The activities of SOD and POD and leaf soluble protein content all increased at lower levels of Na⁺ concentration and then declined, peaking at 102.6 mmol/L NaCl. This study shows that oats have self-protecting mechanisms that adapt to salinity stress. The threshold of salt tolerance was 102.6 mmol/L NaCl. Of the four varieties, Baiyan-6 showed the most tolerance, while Baiyan-2 also revealed good potential. Both varieties could be used as candidates for selecting and breeding better genotypes of salt tolerant oats.