兴安杜鹃种子萌发特性研究

以兴安杜鹃为试材,采用常规观察方法与石蜡切片方法观察种子形态,通过对光照、温度、赤霉素浓度、NaCl胁迫等条件设置不同处理,研究了其种子形态与萌发特性,旨在为兴安杜鹃繁殖培育和苗木生产提供参考依据。结果表明:兴安杜鹃种子成熟时发育至成熟胚阶段,种子细小,千粒质量仅为0.100 4 g。兴安杜鹃种子需光萌发;最适其种子萌发的温度为25℃,过高或过低温度均不利于其种子萌发;一定浓度的赤霉素对其种子萌发有促进作用;NaCl胁迫下兴安杜鹃种子的发芽率、发芽势、发芽指数随盐离子浓度增加呈明显下降趋势,当NaCl浓度超过0.6%时,其种子完全不能萌发。因此,兴安杜鹃种子需光照萌发,最适其萌发温度为25℃,对盐胁迫较为敏感,经600 mg·L^-1赤霉素处理的种子萌发效果最佳,发芽率可达92.67%。

Study on Seeds Germination Characteristics of Rhododendron dauricum L.

Rhododendron dauricum seeds were used as experimental materials,the seeds morphology was observed for conventional observation method and paraffin section method,and different treatments were set by conditions such as light,temperature,GA3 concentration and NaCl stress.The seeds morphology and germination characteristics were studied,which were intended to provide theoretical basis for seed reproduction and resource protection of Rh.dauricum.The results showed that the seeds of Rh.dauricum were small and the 1 000-seed weight was only 0.100 4 g from maturity to mature embryo.The seeds of Rh.dauricum could not germinate in the dark.The optimum temperaturefor seed germination was 25 ℃,higher or lower temperature than the optimum can reduce the germination rate.A suitable concentration of GA3 could promote the germination.Under NaCl stress,the germination rate,the germination potential and germination index decreased significantly with the increase of NaCl concentration.When NaCl concentration exceeded 0.6%,the seeds could not germinate at all.To sum up,the seeds of Rh.dauricum needed light to germinate,and the optimum germination temperature was 25℃.In addition,the germination were sensitive to the salt stress,and can be promoted by GA3 at 600 mg·L^-1,resulting in 92.67% germination rate.