温度、盐分和光照对濒危植物盐桦( Belula halophila )种子萌发特性的影响

Effects of Temperature, Salinity and Light onSeed Germination of Belula halophila

目的:通过研究濒危植物盐桦种子的萌发特征,探索不同温度(20/5℃、25/10℃、30/15℃、35/20℃)、光照(光暗交替和全黑暗)以及盐分浓度(0、50、100、200和300 mmol/L)对盐桦种子萌发的影响,揭示其种子萌发的特性及其濒危的机制。结果:低温或高温能显著抑制盐桦种子萌发,种子萌发的适宜温度为25/10℃或30/15℃;在同一温度、光照下,盐桦种子的萌发率与萌发指数随着盐胁迫浓度增加呈现下降的趋势;温度和盐分对盐桦种子的萌发存在互作关系,低温或高温均显著降低了盐桦种子萌发的耐盐性;在同一温度下,光暗交替与全黑暗条件相比,种子萌发率无显著差异。在适宜温度(25/10℃)下,种子耐盐临界值为99.7 mmol/L,极限值为304.0 mmol/L。结论:阐明了温度和盐分对盐桦种子萌发最主要生态因子,同时光照对其种子萌发影响显著,为拯救濒危植物研究提供了理论依据。

Objective:To study the germination characteristics of the seeds of endangered plants Belula halophila,we explored the effects of different temperatures(20/5℃,25/10℃,30/15℃,35/20℃),all the darkness and dark-light alternation,and salinity concentration(0,50,100,200,and 300 mmol/L)on the seed germination of B.halophila,and revealed the characteristics of its seed germination and the mechanism of its endangered.Results:Low or high temperature could inhibit the germination of B.halophila seeds significantly,and the optimal temperature for seed germination was 25/10℃or 30/15℃.Under the same conditions of temperature and light,the germination rate and germination index of B.halophila seeds decreased with the increase of salt stress concentration.The interaction of temperature and salinity was significantly effected on the germination of B.halophila seeds,and both low temperature and high temperature could significantly reduce the salt tolerance of B.halophila seeds.At the same temperature,there was no significant difference in seed germination rate between all the darkness and dark-light alternation.At suitable temperature(25/10℃),the critical value of salt tolerance of seeds is 99.7 mmol/L,and the limit value is 304.0 mmol/L.Conclusion:The temperature and salinity as most important ecological factors on seed germination of B.halophila,and light had significant effection on seed germination,which provided a theoretical basis for saving endangered plants.