沙生针茅种子萌发特性及其影响因素

摘要

利用控制试验研究了不同温度蒸馏水水分、盐分胁迫等生态因子对沙生针茅种子萌发的影响,探索了沙生针茅种子对各种生态因子的适应性。结果表明：(1)蒸馏水浸泡种子,以60℃温水浸泡、自然降温至常温12 h 最好；(2)低温处理与未经低温处理的种子发芽率差异不显著(P >0.05),说明沙生针茅种子不存在生理后熟因素影响；(3)随着 PEG-6000浓度的增加,沙生针茅种子的发芽率、发芽势、发芽指数呈下降趋势,种子发芽率的 PEG-6000浓度的临界值和极限值分别为15.9%和26.3%；(4)沙生针茅种子的发芽率、发芽势、发芽指数随着盐分浓度的增加呈下降趋势,其中 Na2 CO3处理下的沙生针茅种子萌发率下降幅度明显大于 NaCl,表明沙生针茅种子对相同质量浓度的 Na2 CO3的耐受能力显著低于对 NaCl 的耐受能力。%The effects of temperature,water and salt stresses on seed germination of Stipa glareosa were studied and its adaptation to different ecological factors was discussed as well.The results showed that:(1)the seed germination rate in treatment of soaking with stilled water at 60 ℃ and naturally cooling to room tempera-ture(20 ℃)for 12 hours was the highest;(2)low temperature treatment did not show significant impact(P >0.05),and this suggested that the after-ripening effect does not exist;3)with the increase of the concentration of PEG-6000,the germination rate and germination index showed a decreasing trend.The threshold and limit value of PEG-6000 concentration were 15.9% and 26.3% respectively;4)the seed germination rate and germi-nation index decreased with the increasing salt concentration,in which,the decline range caused by Na2 CO3 was significantly greater than NaCl.