外源物质对盐、旱胁迫下益母草种子萌发和幼苗生长的影响OA

To screen out the optimal exogenous substances and their application concentrations that could promote the germination of Leonurus japonicus seeds and the growth of seedlings under salt and drought stress,different concentrations of exogenous substances,namely brassinolide and gibberel-lin,were used to soak the Leonurus japonicus seeds for 24 hours.The effects of these exogenous sub-stances on the physiological responses of Leonurus japonicus seeds and seedlings under salt and drought stress were studied.The results showed that the gibberellin soaking treatment could signifi-cantly alleviate the stress of salt and drought on the Leonurus japonicus seeds.The gibberellin of 70 mg/L was the most suitable concentration for promoting the germination of Leonurus japonicus seeds under drought stress,and the gibberellin of 50 mg/L was the most suitable concentration for promo-ting the germination of Leonurus japonicus seeds under salt stress.Both treatments significantly pro-moted the growth of the embryonic root and embryonic axis of the Leonurus japonicus seedlings and increased the antioxidant enzyme activity of the seedlings.The brassinolide of 10-5mmol/L was the most suitable concentration for promoting the germination and growth of Leonurus japonicus seeds under salt and drought stress.The comprehensive evaluation results showed that the alleviation effects of gibberellin with 70 mg/L and 50 mg/L on the physiological responses of Leonurus japonicus seeds and seedlings under salt and drought stress were higher than those of the brassinolide of 10-5 mmol/L.The study demonstrated that appropriate concentrations of gibberellin and brassinolide soa-king could promote the germination and growth of Leonurus japonicus seeds under salt and drought stress,and the effect of gibberellin was better.