光照对绒毛番龙眼种子萌发的影响  

Effects of Light Treatment on the Germination of Pometia tomentosa(Sapindaceae) Seeds

作　　者：闫兴富[1] 曹敏[1] 

机构地区：[1]中国科学院西双版纳热带植物园

出　　处：《云南植物研究》2008年第2期183-189,共7页Acta Botanica Yunnanica

基　　金：云南省自然科学基金(2005C0058M);国家重点基础研究发展计划项目(2003CB415100)

摘　　要：在实验室和自然条件下,研究了光照强度和光照时间对西双版纳季节雨林冠层树种绒毛番龙眼(Pometia tomentosa)种子萌发的影响。结果表明:不论是在持续光照还是在周期性光照条件下,3种不同强度光照处理的绒毛番龙眼种子萌发率都很高,均与对照(全黑暗)无显著差异;光照可加快种子萌发速度(降低萌发速率系数),提高萌发指数和幼苗活力指数。人工遮荫有利于绒毛番龙眼种子萌发率的提高,在100%自然全光照(natural sunlight,NS)下萌发率最低(27.8%),而在0.6%NS处理萌发率最高(78.9%);萌发速率系数在全光照下最大,随遮荫程度的增加而降低,萌发指数和幼苗活力指数则随遮荫程度的增加而增大。在遮荫萌发实验中,绒毛番龙眼种子的萌发可能主要受种子脱水敏感性的影响,即强光下剧烈的水分蒸发引起的暂时水分亏缺导致种子脱水死亡或萌发延迟;已经"萌发"的种子也可能因短期水分胁迫而不能生长到"第一对真叶出现"这一萌发标准就死亡,从而降低种子萌发率。在绒毛番龙眼种质资源保护工作中,既要注意避免强光下温度升高引起的种子过度脱水死亡,又要保证提供适宜光照条件以提高萌发质量和幼苗成活率。The present paper examined the effects of light treatments on the seed germination of Pometia tomentosa-a canopy tree species in seasonal rain forest of Xishuanghanna. The results showed that the final germination percentage of P. - tomentosa seed was high under both consecutive illumination and 14 h/10 h hght-darkness cycle of all light intensities, and no significant difference was observed among treatments. Illumination reduced the coefficient of germination rate, but increased germination index and vigor index. The germination percentage increased with decreasing light intensity in shade house and the highest germination percentage （78.9%） was achieved at 0.6% of natural sunlight （NS）, and the lowest germination percentage （27.8%） was achieved at 100% of NS. The germination percentage at 100% of NS was significantly lower than those of shading treatments, although there were no significant differences among shading treatments. The coefficient of germination rate in shading treatment decreased with reducing hght intensity, while germination index and vigor index exhibited a converse tendency. It is suggested that the germination of P. tomentosa seed in shading treatment can be affected by seed desiccation resulting from evaporation of soil water under high light intensity and by the death of ＂germinated seeds＂ which could not grow to match the criterion of germination, This implies that both avoiding the death of seed desiccation resulted from high temperature under high light intensity and improving the quality of seed germination and seedhng survival by providing suitable hght for them are emphasized in the protection of germplasm resources of P. tomentosa.

关 键 词：光照强度 遮荫处理 绒毛番龙眼 种子萌发 西双版纳季节雨林 

分 类 号：Q945[生物学—植物学]