醉马草种子萌发对环境因素的响应

Response of Seed Germination of Achnatherum inebrians to Environmental Factors

以醉马草种子为材料,在环境控制条件下,研究其萌发对温度、光照、水分和pH的响应,旨在明确醉马草种子萌发对环境因素的响应程度,为探讨醉马草快速扩散及成功入侵定植的原因和科学预测提供理论依据。结果表明:醉马草种子在恒温15~35℃和变温15/5~40/30℃下均可萌发,发芽率分别在51%~94%和15%~93%之间,在恒温25℃条件下发芽率最高,种子在45/35℃高温时丧失生活力。在5种光照周期条件下,种子发芽率均达到了90%以上,持续黑暗环境可以促进胚根的生长。种子可以在0^-1.0MPa环境中萌发,但是渗透势的降低会抑制种子的萌发;经21d低渗透势胁迫后,未萌发的种子复水萌发后出现快速补偿生长,并没有丧失活力。在pH 5~10范围内,种子发芽率均超过75%,强酸性环境会抑制种子萌发。醉马草种子在萌发阶段对各种环境因素表现出极强的耐受性,说明醉马草种子在较为极端的环境中仍能继续萌发。

Seed germination is an important prerequisite for plant colonize successfully.In order to clarify the response characteristics of seed germination to environmental factors,Achnatherum inebrians seeds were used as material to study the responses of seed germination to environmental factors such as temperature,light,water and pH under environmental control conditions.The results showed that the seeds could germinate at a constant temperature 15 to 35℃and at variable temperature of 15/5 to 40/30℃,the germination rates were between 51%to 94%and 15%to 93%,respectively.The maximum germination occurred at 25℃.The seed loses vitality at 45/35℃.The germination rates of the seeds were more than 90%under five different photoperiod conditions,and the continuous dark environment could promote the growth of radicle.Seeds can germinate in the environment of 0 to-1.0 MPa,but the decrease of osmotic potential inhibited the germination of seeds;and after 21 days of low osmotic stress,the non-germinated seeds could rapidly compensate and grow after the rehydration germination,and did not lose vitality.Over the range of pH 5 to 10,the seed germination rates were more than 75%,and only strong acid environment inhibited seed germination.The seeds of A.inebrians showed strong tolerance to various environmental factors in the germination stage,which indicated that seeds could continue to germinate in more extreme environments.