百合组培苗对盐胁迫的生理反应

为探讨百合在盐胁迫下一些生理指标的动态变化及其作为抗盐性评价指标的可行性,为百合抗盐机理的研究和抗盐品种的选育提供理论依据,以预试验确定的8 g／L NaCl为百合组培苗的耐盐性阀值,研究了NaCl胁迫对麝香百合(Lilium longiflorum)组培苗几种生理生化指标的影响。结果表明,麝香百合根系和叶片丙二醛(MDA)含量及电导率均较对照明显升高,且根系MDA含量低于叶片,但脯氨酸(Pro)含量变化规律不明显;随盐胁迫时间延长,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性均呈先升后降的趋势,但根系酶活性变化幅度明显小于叶片;同时盐胁迫处理还降低了百合叶片和根系中的ASA含量。但根系ASA含量下降幅度小于叶片。上述结果说明,与叶片相比,百合根系耐盐性更强;MDA含量及电导率均可作为百合抗盐性评价的稳定指标,而Pro含量则不宜。

Physiological effects of NaCl on salt stress of lily plantlets from tissue culture

In oreer to explore the feasibility of lily salt tolerance evaluation under salt stress and mechanism with a view to the selection of salt-resistant varieties and provide a theoretical basis, the physiological index changes of lily plantlets from tissue culture with NaCl treatment were determined. By experiment, the threshold about salt tolerance of lily microplants was 8 g/L NaCl. The results showed that the content of Malondialdehyde (MDA) and the leakage of electrolytes increased when treated with 8 g/L NaCl,and the changes in leaves were more obvious than that in roots. Proline (Pro) content did not show a obvious regulation. The activities of antioxidant enzymes (SOD,POD,CAT and APX) increased under first period of salt stress and then decreased. The change was more obvious in leaves than in roots. Meanwhile,the content of ASA decreased and it changed more rapidly in leaves than in roots. It was concluded that the roots of lily had better salt tolerance than the leaves. MDA and the leakage of electrolytes could be used as stable indicators of the salt tolerance evaluation and Pro is not appropriate.