ABA浸种对混合苏打盐碱胁迫下苜蓿种子萌发受阻的缓解作用

本研究以WL343HQ和龙牧807苜蓿（Medicago sativa L.）品种种子为试验材料，对其种子进行20，25，30，35，40，45，50，55和60 mmol·L^-1苏打盐碱胁迫和25，50，75和100 μmol·L^-1脱落酸（Abscisic acid，ABA）缓解处理，测定了不同苏打盐碱浓度对苜蓿种子发芽率和ABA缓解苏打盐碱胁迫对苜蓿种子萌发指标的影响。结果表明：2种苜蓿种子发芽率均随苏打盐碱胁迫浓度增加呈下降趋势，ABA缓解WL343HQ和龙牧807苏打盐碱胁迫浓度分别为40 mmol·L^-1和35 mmol·L^-1，WL343HQ抗苏打盐碱能力高于龙牧807；随ABA浓度的增加，2种苜蓿种子的发芽率、发芽势、发芽指数、活力指数和芽苗的胚芽长、胚根长、鲜重、干重均呈先升后降趋势。不同ABA浓度对苏打盐碱胁迫下的紫花苜蓿种子萌发均产生一定的缓解作用，特别是ABA浓度为75 μmol·L^-1时缓解作用最明显。本研究结果可为苏打盐渍化土壤苜蓿种植提供一定参考。

The Relieving Effects on Germination Blocked of Medicago sativa Seed under Soda Saline-Alkali Stress of Soak Seed in ABA

In this study,the seeds of WL343HQ and Longmu 807 alfalfa (Medicago sativa L.) were treated with 20,25,30,35,40,45,50,55 and 60 mmol·L^-1 soda saline-alkali and 25,50,75 and 100 μmol·L^-1 Abscisic acid.The effects of different doses of soda saline-alkali on germination rate of alfalfa seed and ABA relieving of soda saline-alkali stress on germination index of alfalfa seed were determined.The results showed that the germination rate of two alfalfa decreased with the increase of soda saline-alkali concentration. ABA relieved the stress of WL343HQ and Longmu 807 induced by soda saline-alkali at 40 and 35 mmol·L^-1. WL343HQ was more resistance to soda saline-alkali when compared with Longmu 807;With the increase of ABA concentration,the germination rate,germination potential,germination index,vigor index,embrgo length,radicle length,fresh weight and dry weight of two alfalfa seeds increased first and then decreased. ABA,especially at the concentration of 75 μmol·L^-1,relieved the stress of germination of alfalfa seeds induced by soda saline-alkali. This study provides a reference for alfalfa planting in soda salinized soil.