混合盐胁迫对马蔺幼苗根系构型及生长量的影响

为探讨不同种类盐胁迫对马蔺幼苗生长状况的影响,采用室内培养的方法,研究总质量浓度为0.3%的NaCl、NaHCO₃单盐溶液及其不同配比的混合盐溶液胁迫对马蔺(Iris lactea var. chinensis)幼苗生长量、地上部干鲜重比值、地下部干鲜重比值以及根系构型的影响。结果表明,随着胁迫时间的延长,0.3%NaCl溶液对叶数和株高增长量的影响最小,其次为3种混合盐溶液,各处理在第14天时株高增幅达到最大。经0.3%NaHCO₃处理后的幼苗地上部干鲜重的比值为空白对照的2.17倍,地下部干鲜重则为空白对照的56.61%,随着混合溶液中NaHCO₃浓度的上升,地上部干鲜重比值表现出上升的趋势,地下部干鲜重比值则表现出下降的趋势。经35天处理后,0.3%NaHCO₃胁迫的马蔺幼苗根系总长、根系表面积较对照均显著下降,降幅分别为39.73%、26.08%,而各处理间的根系体积却无显著差异。研究结果显示,0.3%NaHCO₃溶液对马蔺幼苗的胁迫作用最强,2种单盐对根系的胁迫作用强于混合盐胁迫,而0.3%NaCl溶液对生长量的胁迫作用最弱。

Effects of Mixed Salt Stress on Biomass and Root Architecture of Iris lactea var. chinensis

The paper aims to study the effects of different salt stresses on the growth of the Iris lactea var. chinensis seedlings. The effects of NaCl and NaHCO₃ single salt and different concentrations of salt solution on the root morphology, the ratio of dry weight to fresh weight in aboveground and underground, and the biomass were studied by means of indoor culture. The results showed that with the prolongation of stress time, the effect of 0.3% NaCl on leaf number and plant height growth was the smallest, followed by three mixed salt solutions, and the plant height increase reached the maximum on the 14 ^th day. The ratio of dry weight of shoots in the shoots treated with 0.3% NaHCO₃ was 2.17 times of that of the blank control, and the dry weight of the shoots was 56.61% of the blank control. With the increase of NaHCO₃ concentration in the mixed solution, the ratio of dry and fresh weight of the aboveground part showed an upward trend, and the ratio of dry to fresh weight in the ground showed a downward trend. After 35 days of treatment, the root length and root surface area of the horseshoe roots of 0.3% NaHCO₃ stress decreased significantly compared with the control, by 39.73% and 26.08%, respectively, but there was no significant difference in root volume between the treatments. The results showed that 0.3% NaHCO₃ solution had the strongest stress on the seedlings of Iris lactea var. chinensis, and the stress of the two single salts on the roots was stronger than that of the mixed salt, while the 0.3% NaCl solution had the weakest effect on the growth.