五蕊寄生种子萌发特性

Germination Characteristics of Dendrophthoe pentandra Seeds

采用室内与野外实验相结合的方法,对五蕊寄生(Dendrophthoe pentandra) 种子萌发特性以及鸟类消化过程对其种子萌发的影响进行研究。结果表明: 五蕊寄生种子对温度和光照较敏感,与黑暗条件相比,光照能显著提高种子的萌发率;20 ℃为种子萌发的最适温度,萌发率达 53. 8%,高温 35 ℃及低温10 ℃均不利于种子萌发。研究发现纯色啄花鸟(Dicaeum concolor) 是该植物的主要食果者,种子外的果肉不是限制种子萌发的关键因素,人为去除果肉并不能提高种子的萌发率,但可缩短种子萌发的时间,果实通过纯色啄花鸟类肠道消化后,随着粪便排出的种子萌发率显著提高(达69%),暗示纯色啄花鸟在五蕊寄生的种子萌发过程中具有重要的作用。

The biological characteristics of seed germination and the effects of dispersal birds on the seed germina-tion of Dendrophthoe pentandra were explored in this paper. Results showed that the seeds of D. pentandra were sen-sitive to the light and temperature. The germination percentage in light condition was significantly higher than that under dark condition. The most suitable temperature for the seed germination of D. pentandra was 20 ℃, it could be as high as 53.8%, and few seeds germinated when the temperature was 10 ℃ or 35 ℃. Our observation identified that Dicaeum concolor was the dominant disperser of D. pentandra seeds in our study sites. We also confirmed that the duration of germination become shorter when the pulp was manually peeled but the germination percentage did not signifieantly change. However, the germination percentage was significantly higher （69%） when the seeds were digested by D. concolor, to compare with those of intact seeds or manually extracted pulp seeds. Our results indica-ted that D. concolor made larger contribution to improve the seed germination of D. pentandra.