独脚金内酯(SLs)对盐碱胁迫下恒山黄芪种子萌发和幼苗生长的影响

Effects of Strigolactones on Seed Germination and Seedling Growth of Hengshan Astragalus membranaceus under Saline-alkali Stress

采用种子萌发试验和幼苗盆栽试验,通过不同比例混合中性盐(NaCl、Na_(2)SO_(4))和碱性盐(NaHCO_(3)、Na_(2)CO_(3))并设置对照(ck)、中度盐碱胁迫(MT)和重度盐碱胁迫(ST),研究外施1μmol/L SLs溶液对不同盐碱胁迫下恒山黄芪种子萌发和幼苗生长生理指标的影响。结果表明,盐碱胁迫显著抑制了恒山黄芪种子萌发和幼苗生长,MT处理组幼苗相比ck和ST处理组具有较高水平的AsA-GSH循环抗氧化能力以及次生产物含量。外施SLs能不同程度地促进MT和ST处理组恒山黄芪的种子萌发和幼苗生长,且对MT处理组的综合提升效果更佳,能明显提高种子的发芽势、发芽率、发芽指数和活力指数;能明显增强幼苗叶片AsA-GSH循环中抗氧化剂(AsA、GSH)含量、氧化还原状态(AsA/DHA、GSH/GSSG)和APX等关键酶活性以及次生产物黄酮、多糖和皂苷积累,从而降低O_(2)·-、H_(2)O_(2)及MDA含量。

The effects of exogenous application of 1μmol/L strigolactones(SLs)solution on seed germination and seedling growth and physiological indicators of Hengshan Astragalus membranaceus under different saline-alkali stress were studied by using seed germination test and soil-potted seedling experiment and mixing neutral salt(NaCl,Na_(2)SO_(4))and alkaline salt(NaHCO_(3),Na_(2)CO_(3))in different proportions and concentration gradients to simulate the control(ck),moderate saline-alkali stress(MT)and severe saline-alkali stress(ST).The results showed that saline-alkali stress significantly inhibited the seed germination and seedling growth of Hengshan Astragalus membranaceus,and the seedlings of MT treatments had higher levels of AsA-GSH cycle antioxidant capacity and secondary metabolites contents than ck and ST treatments.Exogenous application of SLs could improve the seed germination and seedling growth of Hengshan Astragalus membranaceus of MT and ST treatments to different degrees,and had the better comprehensive improvement effects on MT treatmens,which could significantly improve the seed germination potential,germination rate,germination index,and vitality index,and obviously increase the antioxidants(AsA,GSH)contents,the redox states(AsA/DHA,GSH/GSSG)and the AsA-GSH cycle key enzymes activities such as APX,and also dramatically enhance the flavonoids,polysaccharides and saponins accumulation,thereby reducing the O_(2)·-,H_(2)O_(2) and MDA contents.