摘要
对2008年和2009年采自浙江天目山的野生天目铁木植株的种子进行萌发实验,以探讨种子的休眠及萌发特征.设置不同的低温储存时间、赤霉素浓度、变温温度、有无光照及不同的发芽基质等条件,比较种子在不同条件下的萌发率.结果表明,吸水实验中种子浸水4 h后吸水率20%,与浸种前重量有明显差异(P<0.05,t-test),表明不属于结构休眠类型.采种后经过短期低温(约4周)储存的种子累积萌发率高于经过较长时间低温(约16周)储存的种子萌发率(p<0.05,t-test),表明种子在低温下被诱导休眠并降低了发芽潜力.种子萌发需要较长时间的高温打破休眠(MLG为54 d),推测可能属于较深的生理休眠类型.赤霉酸对天目铁木种子萌发有显著的促进作用,15/25℃加之施用浓度为400或600 mg·L^(-1)的赤霉酸,是种子适宜的萌发条件.在天目铁木迁地保护中,可采种后人工施加赤霉酸,立即在恒温培养箱中萌发,以获得较高的萌发率.
Ostrya rehderiana is a critically endangered plant species with only five natural individuals remaining in Tianmu Mountain,Zhejiang Province,China.To explore the seed dormancy and germination of O.rehderiana,the seeds were collected from the natural individuals in November 2008 and 2009 and manipulated in illumination incubator in different treatments.Results showed that these seeds have a water absorption rate of 20% after immerging in water for 4 h （p〈0.05）,indicating it was not physical dormancy （PY）.The seeds have higher cumulative germination rates after short low temperature storage （4 weeks v.s.16 weeks; p〈0.05）,suggesting low temperature might induce seeds dormancy of O.rehderiana.To break dormancy,relative longer times （median length of germination time =54 d） of temperature above 15 ℃ were needed,indicating the seeds may belong to physiological dormancy （PD）.The most favorable germination condition was 15/25 ℃ employing 400 or 600 mg · L-1 GA.We conclude that seeds treated with GA should be sown in a fitting condition immediately to germinate well in the ex situ conservation of O.rehderiana.In addition,it is a feasible method that seeds germinate in the nature with added GA artificially.
出处
《华东师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第6期150-158,共9页
Journal of East China Normal University(Natural Science)
关键词
天目铁木
种子休眠
萌发率
温度
赤霉酸
Ostrya rehderiana
seed dormancy
germination rate
temperature
gibberellin （GA）
