入侵植物喜旱莲子草对光、氮及其互作的表型可塑性反应

Phenotypic Plasticity of Alternanthera philoxeroides to Light,Nitrogen and Their Interaction

为给入侵植物喜旱莲子草的管理与防控提供一定的理论参考,对其在光照和氮沉降及光氮互作的表型可塑性反应进行了研究。结果表明:喜旱莲子草通过增加株高、节长,降低根重比,提高叶重比、叶片叶绿素含量来适应较低的光照环境,其株高、节长、总生物量对光照的表型可塑性指数较大;随着土壤氮素的增加,喜旱莲子草植株的株高、节长、茎粗、叶长、叶宽、总生物量和叶绿素都显著增加,其对氮沉降的可塑性指数在株高、生物量和叶绿素上较大;氮沉降有利于喜旱莲子草对光照反应可塑性的增加,从而补偿低光环境导致的生长不利。因此,若在持续高氮沉降的情况下,喜旱莲子草种群有向贫瘠土壤和弱光环境拓展的风险。

The phenotypic plasticity of Alternanthera philoxeroides to light,nitrogen and their interaction was studied to provide the theoretical basis for management and control of Alternanthera philoxeroides.The results showed that Alternanthera philoxeroides plants could increase leaf weight ratio and leaf chlorophyll content to adapt lower light intensity by raising plant height,nodal length and reducing root weight ratio,the phenotypic plasticity index of plant height,nodal length and total biomass to light was high,the plant height,nodal length,stem diameter,leaf length,leaf width,total biomass and chlorophyll content of Alternanthera philoxeroides plants significantly increased with nitrogen increase in soil and the phenotypic plasticity index of plant height,biomass and chlorophyll content of Alternanthera philoxeroides plants to nitrogen deposition was higher in all factors.The nitrogen deposition is beneficial to plasticity increase of Alternanthera philoxeroides plants to light,which can compensate growth of Alternanthera philoxeroides plants under lower light intensity.