【摘要】 为了探知紫花苜蓿和黄花苜蓿种子萌发期对逆境胁迫的适应能力,采用8个不同浓度的聚乙二醇(PEG-6000)溶液模拟干旱条件,研究了紫花苜蓿和黄花苜蓿种子萌发和幼苗生长对干旱的响应,评价了二者的抗旱性。结果表明,在非干旱和干旱条件下,紫花苜蓿的发芽率、发芽势、发芽指数、活力指数、根长、苗长均高于黄花苜蓿。轻度干旱(PEG 4%)可促进两种苜蓿的种子萌发;中度干旱(PEG 8%~12%)对两种苜蓿的种子萌发和幼苗生长产生显著抑制作用;重度干旱(PEG 16%~20%)抑制作用更强。黄花苜蓿受抑制程度大于紫花苜蓿。极端干旱条件(PEG 24%~32%)下,两种苜蓿的种子完全受到抑制,不能萌发,但种子活力依然存在。复水至水分条件适宜时,仍能萌发。参考隶属函数法采用多个相对指标的综合评价结果表明紫花苜蓿种子萌发期的抗旱性高于黄花苜蓿。更多还原

【Abstract】 The adaptability of Medicago sativa L.(M1)and M.falcata L.(M2)in seed germination period to water stress were studied.The drought conditions were simulated with 8 different concentrations of PEG-6000 solution.The results showed that the germination rate,germination potential,germination index,vigor index,root length and seedling growth of Medicago sativa L.were higher than those of M.falcata L.Slight drought(4%)could promote the germination of the alfalfa,moderate drought conditions(PEG 8% ~ 12%)significantly inhibited the seed germination and seedling growth,while in the heavy drought condition(PEG 16% ~ 20%),the inhibitory effect become more stronger,and M.falcata L.was more inhibited than Medicago sativa L.Under extreme drought conditions(PEG 24% ~ 32%),the seed germination of the two alfalfa was completely inhibited,but the seed vigor still existed.The seeds could germinate when the water condition became suitable.The results of comprehensive evaluation of the membership function method showed that the drought resistance of Medicago sativa L.at seed germination period was higher than that of M.falcata L.更多还原