旱、盐胁迫下黄芪种子萌发及其对水杨酸的响应

摘要

To study the variations in seed germination between Astragalus membranaceus and A.membrana-ceus var.mongholicus under polyethylene glycol (PEG)and NaCl stresses,and to explore the differences in protective effects of salicylic acid (SA)for the two cultivars of A.membranaceus under severe PEG and NaCl stresses,we measured (1)the total germination percentage (TGP),germination energy (GE),vigor index (VI),shoot length (SL),root length (RL),shoot dry weight (SDW),and root dry weight (RDW)of two cultivars of A.membranaceus under gradually enhanced PEG and NaCl stresses;and(2)the differences in TGP of the two cultivars between application methods and concentrations of SA under severe PEG and NaCl stresses. Our results showed that all measurements of the two cultivars decreased with increasing stress intensity.Both low concentrations of PEG and NaCl can enhance seed germination in A.membranaceus.The VI in A.membranaceus var.mongholicus was higher than in A.membranaceus at —0.5 MPa PEG and —0.7 MPa NaCl stress levels (P<0.0 5).Soaking seeds with SA can enhance the TGP of of A.membranaceus.and A.membranaceus var.mongholicas The stress tolerance of A.membranaceus var.mongholicus was stronger than A.membranaceus.There were signifi-cant differences in seed performances between the two cultivars treated with SA.Soaking seeds with SA is was more effective than mixing seeds with SA.%通过测定不同浓度聚乙二醇(PEG)和 NaCl 胁迫下膜荚黄芪(Astragalus membranaceus)和蒙古黄芪(A.mem-branaceus var.mongholicus)种子的最终发芽率、发芽势、简化活力指数、苗长、根长、苗干重、根干重等指标,以及不同施用方式和浓度的水杨酸(SA)对重度PEG和 NaCl胁迫下两种黄芪种子最终发芽率的影响,旨在研究两种黄芪种子对PEG和 NaCl胁迫响应方式的异同及 SA对两种黄芪种子在重度PEG和 NaCl胁迫下保护效果的差异.结果表明,低浓度PEG和 NaCl只能促进膜荚黄芪种子萌发.在—0.5 MPa PEG和—0.7 MPa NaCl 处理下,蒙古黄芪种子的活力指数显著优于膜荚黄芪种子(P<0.05).SA浸种能促进重度PEG和 NaCl胁迫下两种黄芪种子的最终发芽率.蒙古黄芪种子的耐胁迫性高于膜荚黄芪种子.两种黄芪种子对 SA的响应方式有区别.SA浸种处理优于拌种处理.