过路黄克隆生长对光照强度的反应

Clonal Growth of Lysimachia christinae in Response to Light Intensity

利用遮阳网产生光照梯度,以研究光照强度对克隆植物过路黄(Lysimachiachristinae)形态特征和生物量分配的影响.结果表明:1)匍匐茎节间长度随光照强度的减弱而增大,遮荫明显增加过路黄的分枝角度,分枝强度没有对光强发生显著反应.遮荫使叶柄变长,而根长则变短.2)随光照强度的减弱,叶柄生物量逐渐增大;遮荫降低了叶生物量、根生物量、总生物量、根生物量比和地下生物量/地上生物量.3)在遮荫条件下,一级匍匐茎基部分株的叶生物量和分株总生物量显著大于顶部分株,而根冠比则相反.根的生物量在各分株间无显著差异.在不遮荫条件下,仅匍匐茎基部分株的叶生物量大于顶部分株,其它的生物量指标在各分株间无显著差异.在分株水平,分株的根冠比不受光强的影响.总之,过路黄的克隆生长在基株和分株水平都对光强作出了明显的反应,而且这种反应具有等级性.

Variation in phenotype and biomass of clonal plasticity of stoloniferous herb Lysimachia christinae was examined in response to a light intensity gradient artificially created using plastic shade wet. The results showed: 1) Stolon internode length with decreasing light intensity, shading increased branching angle, and petiole length was longer in shading condition, while the opposite was true for root length. Stolon number did not respond to the treatments. 2) Petiole biomass increased with decreasing light intensity. Leaf biomass, stolon biomass, above_ground biomass and total biomass did not respond to the treatments. Shading decreased root biomass, leaf biomass, total biomass, root biomass ratio and below_ground biomass/ above_ground biomass. 3) In shading condition, leaf biomass and total biomass of ramets at the the base of primary stolon were bigger than those of ramets at the apex of primary stolon, while the opposite was true for root_shoot ratio. Root biomass was not significant difference among ramets along primary stolon. To not shaded ramets, only leaf biomass of ramets at the base of primary stolon was bigger than those of ramets at the apex of primary stolon. Effects of light intensity on clonal growth were measured at two levels of genet and ramet. This meant L. christinae can hierarchically respond to light intensity.