Abstract: In order to screen out the treatment measures for improving the germination ability of Medicago ruthenica seeds at low temperature,M. ruthenica were soaked with salicylic acid (SA) and abscisic acid (ABA) with 7 different concentrations in the study. The effects of two exogenous substances on germination energy,germination percentage,germination index,vigor index,root and bud length of M. ruthenica at low temperature were determined. The results showed that the germination energy,germination percentage,germination index,vigor index,root and bud length of M. ruthenica increased first and then decreased under the treatment of two kinds of exogenous substances,and the number of days of initial germination did not change. In these test treatments,low concentration SA (0.1～10 μmol·L^-1) and ABA (0.001～0.5 μmol·L^-1) promoted the seed germination and root,bud elongation of M. ruthenica,while high concentration SA (>20 μmol·L^-1) and ABA (>1 μmol·L^-1) significantly inhibited the seed germination and root,bud elongation (P<0.05). Through the comprehensive evaluation of fuzzy mathematics membership function,0.05 μmol·L^-1 ABA was the best concentration to promote the germination and seedling growth of M. ruthenica at low temperature.

Key words: Medicago ruthenica, Low temperature, Salicylic acid, Abscisic acid, Germination, Seedling growth

摘要： 为筛选出提高低温下扁蓿豆（Medicago ruthenica）种子发芽能力的处理措施，本研究选取水杨酸（salicylic acid，SA）和脱落酸（abscisic acid，ABA）分别对扁蓿豆进行了7种不同浓度的浸种处理，测定了2种外源物质对低温下扁蓿豆种子发芽势﹑发芽率﹑发芽指数﹑活力指数、根长和芽长的影响。结果表明，2种外源物质浸种处理下扁蓿豆种子的发芽势﹑发芽率﹑发芽指数﹑活力指数，根长和芽长均呈先升高后降低的趋势，初次发芽天数无变化。供试处理中，低浓度的SA（0.1～10 μmol·L^-1）和ABA（0.001～0.5 μmol·L^-1）对扁蓿豆种子萌发﹑根长和芽长均有促进作用，且对根长和芽长的促进效果较种子萌发好，高浓度的SA（>20 μmol·L^-1）和ABA（>1 μmol·L^-1）显著抑制了种子萌发及根和芽的伸长（P<0.05）。通过模糊数学隶属函数的综合评价，0.05 μmol·L^-1的ABA浸种处理是低温下促进扁蓿豆种子萌发和幼苗生长的最佳浓度。

关键词: 扁蓿豆, 低温, 水杨酸, 脱落酸, 萌发, 幼苗生长