烟草幼苗对复合盐碱的生理响应

Physiological responses of tobacco seedlings to saline-alkali stress

【目的】研究烟草幼苗在复合盐碱处理下的生理代谢变化。【方法】以n(NaCl):n(Na2SO4):n(NaHCO3)=1:1:1的比例,设置5个质量浓度复合盐碱处理,测定各处理烟苗根系指标和叶片生理指标。【结果】1)随着复合盐碱浓度增加,烟苗总根长呈降低趋势,根表面积、根尖数和根活力都表现出先升后降趋势;2)低浓度短时间盐碱处理促进叶绿素积累,时间延长或浓度增加使叶绿素含量下降;3)随处理浓度升高和时间延长,叶片含水率下降,MDA含量和相对电导率升高,可溶性糖和脯氨酸含量先升后降;4)低浓度盐碱处理ABA含量变化不明显,ZR含量下降,高浓度盐碱处理时这两种激素含量均有升高趋势。【结论】0.3%复合盐碱、短期的复合盐碱处理可促进烟苗的生长,盐碱胁迫时间延长或浓度升高则会影响烟株正常生长发育。

[Objective]This study aims to investigate the physiological and metabolic changes of tobacco seedlings under compound saline-alkali treatment.[Method]Five mass-concentrations compound saline-alkali treatments were set up,with the ratio of n(NaCl):n(Na2SO4):n(NaHCO3)=1:1:1.The root index and leaf physiological index under each treatment were measured.[Results]1)As the compound saline-alkali concentration increased,the total root length of tobacco seedlings decreased,and the root surface area,root tip number,and root vigor all showed a tendency of first increasing and then decreasing;2)low-concentration and short-term saline-alkali treatment could promote chlorophyll accumulation,but prolonged treatment time or increased concentration of saline-alkali treatment would decrease chlorophyll content of tobacco seedlings;3)With the increase of treatment concentration and extension of treatment time,leaf moisture content decreased,MDA content and relative conductivity increased,soluble sugar and proline content increased first and then decreased;4)The ABA content of tobacco seedlings treated with low-concentration saline-alkali treatments did not change significantly,but the ZR content decreased.The contents of two hormones both increased during high-concentration saline-alkali treatments.[Conclusion]Under the conditions of this experiment,0.3%compound saline-alkali treatment and short-term compound saline-alkali treatment can promote the growth of tobacco seedlings.Prolonged saline-alkali stress time or increased treatment concentration will affect the normal growth and development of tobacco plants.