中国特有药用植物黄花胡椒种子萌发特性研究

Seed Germination Characteristics of Piper flaviflorum,an Endemic Medical Plant to China

黄花胡椒(Piper flaviflorum)是胡椒科(Piperaceae)多年生木质藤本植物,为我国特有,目前主要分布于云南中南部至西南部,分布范围狭窄、资源量小。为找出生殖环节中的关键因素,对黄花种子萌发特性进行了研究。结果表明:种子骨质硬种皮在一定程度上减慢了对水分的吸收速率,但并未影响其最终吸水量,不存在吸涨障碍;对比分析不同环境温度下种子的萌发特性,除5℃时萌发率为0外,在10~35℃温度范围内均有一定的萌发率,随着温度升高萌发时间提前,萌发速率加快,其中25℃温度条件下萌发率最高,达80.00%±7.21%,而极端高温和极端低温均不利于萌发;不同光照条件下种子均可获得较高的萌发率,各处理间差异不显著(p>0.05),不利于种子库的建立和适应不稳定生境;种子萌发对湿度的响应较为敏感,最佳萌发土壤含水量为15%,过低和过高均不利于萌发;种子播种在河沙和沙壤土中的萌发率超过75%,而在水稻土中的萌发率最低,为53.33%±5.03%。

Piper flaviflorum, an endemic member to China, was a deciduous woody liana species with small geographic distribution in South Central and South East Yunnan Province. To explore the underlying mechanism relevant to the impediment in its sexual reproduction, experiments were, therefore, conducted to define the optimum environmental condition for seed germination. The results were as follows. The hard seed coat reduced the water absorption rate of its seeds to some extent but did not affect its final water absorption, so there was no water absorption obstacle. A temperature ranging from 15-25 ℃ was suitable for seed germination with an optimum of 25 ℃, and at 5 ℃ germination was inhibited. As the temperature raised, germination was accelerated. Extremely high or low temperature had a detrimental effect on germination. Compared with those in light, darkness did not decrease germination rate and the seeds had adapted well to extremely low light intensity. P. flaviflorum could germinate in an abroad range of light intensity and temperature, which allowed the seeds starting germination process in shaded habitats, but not conductive to formation of the seed bank and adaptation to severe environment. Germination was affected by sand moisture content remarkably with an optimal content of 15%. In the case of container seedling culture, 〉75% seedlings emerged out of the river sand and sand soil, while in paddy soil only 53.33%±5.03%.