四季竹对不同浓度NaCl胁迫的生理响应

以夏秋季优良笋用竹种四季竹盆栽苗为材料,研究了土壤中1‰~6‰浓度NaCl(干重)处理对四季竹叶片脱落率、离子渗漏率、丙二醛(MDA)含量、抗氧化酶活性以及渗透调节物质含量的变化特征,以探讨四季竹的抗盐机理。结果表明:(1)随NaCl浓度的增大和处理时间的延长,四季竹叶片脱落率逐渐增加;四季竹在1‰~2‰NaCl浓度下的土壤中生长良好,在3‰~5‰浓度下随处理浓度的增大伤害逐渐加重,但这种伤害是可逆的,6‰是四季竹的半致死盐浓度。(2)叶片离子渗漏率随NaCl浓度的增大而显著增大,在6‰浓度处理下随处理时间的延长近直线升高,在3‰~5‰浓度下先升高后降低,而在1‰~2‰浓度处理下变化平缓且与同期对照无显著差异;叶片MDA含量随NaCl浓度的增大而增加,随处理时间的延长先增加后降低。(3)四季竹叶片SOD和POD活性在胁迫3~15 d均出现先下降后上升的过程,其有一定的锻炼适应性;叶片脯氨酸含量随NaCl处理浓度的增大而增加,其随处理时间的延长在1‰~2‰浓度处理下变化平缓,在3‰~6‰浓度处理下显著增加后减小;各浓度处理的可溶性蛋白含量随处理时间的延长先增加后减小,但均高于对照。研究发现,四季竹是较耐盐竹种,其可以通过调控自身保护酶活性和渗透调节物质含量来有效缓解盐胁迫伤害,从而表现出一定的耐盐能力。

Physiological Response of Oligostachyum lubricum to Different NaCl Stress

Physiological response of Oligostachyum lubricum to different NaCl concentrations was studied in a pot experiment with treatments of different NaCl content(0 CK,1‰,2‰,3‰,4‰,5‰,6‰) in soil.Leaf dropping rate,ion leakage rate,MDA content,antioxidant enzyme activity and osmotic adjustment substance contents in leaves were investigated.The results showed that:(1)Leaf dropping rate increased with increasing of NaCl content and treated time.O.lubricum grew well in soil with 1‰～2‰ NaCl content and injured at 3‰～5‰ NaCl content,but the injury was reversible,and 6‰ was the threshold content.(2)Ion leakage rate increased significantly with increasing NaCl content in soil.With prolonged treatment duration,ion leakage rate increased with 6‰ NaCl treatment in soil.While that treated with 3‰～5‰ NaCl content firstly increased and then decreased,and that treated by 1‰～2‰ NaCl contents changed only slightly and had no significant difference with CK.MDA content in leaves increased with increasing NaCl content,and increased first and then declined with increasing treated time.(3)SOD and POD activities declined firstly and then increased after been treated 3 to 15 days by NaCl,which showed that O.lubricum had the ability of hardening adaptation.Proline contents were proportional to treated NaCl content and that treated by 1‰～2‰ content changed slightly and had no significant difference with the control,while that treated by 3‰～6‰ contents increased and then decreased significantly.Soluble protein content in leaves treated by NaCl was higher than that of the control and increased firstly and then decreased along with the time passed by.The results indicated that O.lubricum was a better salt tolerant bamboo species and could avoid salt harms by adjusting it’s antioxidant enzyme system and osmotic adjustment system.