中华补血草组培苗对NaCl胁迫的生长及生理响应

Effect of NaCl Stress on Growth and Physiological Response of Limonium sinense in vitro

利用组织培养技术,在含不同浓度NaCl(0、0.2%、0.4%、0.6%、0.8%、1.0%)的MS增殖及生根培养基上对叶片分化苗进行盐胁迫处理,测定并分析了中华补血草的生长发育指标(株高、叶数、叶宽、植株鲜样质量、根长)和生理指标(MDA、SOD、Pro、Na^+、K^+)变化情况。结果表明:在不同浓度NaCl胁迫下,中华补血草组培苗的生长指标均未表现出明显的盐害症状。其中,根长随NaCl浓度增加而增加,1.0%浓度时主根最长,为对照的3.9倍;株高随NaCl浓度的增加呈先增加后降低然后再增加的趋势,0.6%浓度处理时最低,0.8%浓度处理时最高,1.0%浓度处理时有所下降,但与0.8%浓度处理的差异不显著;植株鲜样质量除0.2%处理与对照差异不显著外,其它处理均显著低于对照且这些处理间的差异不显著;叶数总体上随着盐浓度的增加而减少,1.0%浓度处理的叶数最少,为对照的1/3;叶宽随盐浓度的增加呈先降低后增加的趋势,0.4%浓度处理时叶最窄,0.8%浓度处理时叶最宽,但与1.0%处理的叶宽差异不显著。生理指标的测定结果表明:MDA含量、SOD活性和Pro含量均随NaCl浓度增加呈先增加后降低的趋势。MDA含量在0.6%浓度处理时最高,并显著高于对照,在1.0%浓度处理时最低,且显著低于对照;Pro含量也在0.6%浓度处理时最高,并显著高于对照,在1.0%浓度处理时含量虽有所下降,但也显著高于对照;SOD活性在0.8%浓度处理时最高,其次为1.0%浓度处理,二者间差异显著,且均显著高于对照。Na^+、K^+含量均显著高于对照,且Na^+、K^+含量总体上随NaCl浓度的增加而显著增加,K^+/Na^+比随NaCl浓度的增加出现先降低后增加的现象,在0.8%浓度处理时比值最小,1.0%浓度处理时K+/Na+比值显著增加。综上所述,组培苗可以耐含NaCl为1.0%浓度的盐汁生境,在其受到盐胁迫时,可以通过增加SOD活性和Pro含量以及维持高K^+/Na^+比值来保护细胞膜系统,增强吸水能力,缓解盐害。

Differentiation seedlings was cultured on the MS proliferation and rooting medium with different NaCl concentration（0,0.2%,0.4%,0.6%,0.8%,1.0%）,and the growth（plant height,the number of leaves,leaf width,fresh weight,root length）and physiological（MDA,SOD,Pro,Na^＋,K^＋）indexes were measured and analyzed.The results showed that the growth of plantlet in vitro grew well under salt stress.With the NaCl stress increasing,the root length increased and was the longest in the NaCl concentration of 1.0%,and it was 3.9times of the control;the plant height increased first then decreased and then increased again,it was the lowest in the NaCl concentration of 0.6%and the highest in the NaCl concentration of 0.8%,when the NaCl concentration was 1.0%,the plant height decreased to some extent,but the difference of the plant height was not significant between the NaCl concentration of 0.8% and1.0%;the differenc of fresh weight in NaCl concentration of 0.2% was not significant compared with the control,the remaining treatments（NaCl concentration of 0.4%-1.0%）were significantly lower than the control,and the difference among them were not significant;the number of leaves decreased with the increase of the NaCl concentration,the number of leaves was the least in NaCl concentration of 1.0%,and was controlled by 1/3;the leaf width increased then decreased,the leaf width was the most narrow in the NaCl concentration of 0.4%,and the leaf width was the widest in the NaCl concentration of 0.8%,the difference of the leaf width was not significant between the NaCl concentration of0.8% and 1.0%.The results of the physiological indexes showed that,MDA content,the activity of SOD and Pro content increased then decreased with the NaCl stress increasing.The contents of MDA were the highest and the lowest respectively in the NaCl concentration of 0.6% and 1.0%,and compared with the control,the contents of MDA were significantly higher in the NaCl concentration of 0.6% and lower significantly in the NaCl concentration of 1.0%;the contents of Pro were significantly higher than that of CK whether the NaCl concentration of 0.6% or 1.0%,and the contents of Pro was the highest in the NaCl concentration of 0.6%,and the contents of Pro decreased in the NaCl concentration of 1.0%;the activities of SOD were significantly higher than that of CK whether the NaCl concentration of0.8% or 1.0%,and the activities of SOD was the highest in the NaCl concentration of 0.8%,and the second was the NaCl concentration of 1.0%.The contents of Na^＋and K^＋were all significantly higher that of CK,and also significantly increased with the NaCl stress increasing.With the NaCl stress increasing,ratio of K^＋/Na^＋decreased then increased,ratio of K^＋/Na^＋was the lowest in the NaCl concentration of 0.8%,and significantly increased in the NaCl concentration of 1.0%.In conclusion,L.sinensecould endure as high as 1.0% NaCl,it could protect cell membrane system and enhance water absorption capacity to alleviating plant salinity injury by increasing the activities of SOD,the content of Pro and maintaining high K^＋/Na^＋ratio.