两种生态型东南景天(Sedum alfredii Hance)根系互作效应对植株生长及吸收利用土壤Zn的影响  

Effects of Root Interaction Between Two Ecotypes of Sedum alfredii Hance on Plant Growth and Soil Zinc Uptake and Utilization

作　　者：龙新宪[1] 王艳红[1,2] 吴启堂[1] 

机构地区：[1]华南农业大学资源与环境学院,广东广州510642 [2]广东省农业科学院土壤肥料研究所,广东广州510640

出　　处：《农业环境科学学报》2008年第1期92-98,共7页Journal of Agro-Environment Science

基　　金：国家自然科学基金资助(20407008)

摘　　要：采用盆栽套种方法探讨了不同程度根系互作对两种生态型东南景天的生长和吸收利用土壤Zn的影响,以及超积累生态型东南景天的根系是否能活化土壤中难利用态Zn。不同程度的根系互作采用不同隔膜处理,即无隔膜处理、400目尼龙筛布隔开和PVC板隔开。结果发现,当两种生态型东南景天套种时,不同程度的根系互作对非超积累生态型东南景天的地上部和根系的生物量、根系Zn含量有显著影响。当与超积累生态型东南景天的根系完全交互作用或采用400目尼龙筛布隔开时,非超积累生态型的根系Zn含量显著增加,其地上部和根系生物量比其单种时显著减少。这些结果间接表明,超积累生态型东南景天根系能够活化土壤中的难溶态Zn。The hyperaccumulating ecotype of Sedum alfredii Hance has exceptional abilities to mobilize and uptake Zn from soil. The study, through interplanting non-hyperaccumulating ecotype of S. alfredii Hance as a bioassay, was to test if the roots of the hyperaccumulating ecotype can mobilize Zn from less-available pools in the soil and this mobilization of Zn in the rhizosphere of the hyperaccumulating ecotype of S. alfredii Hance would increase the uptake of Zn and inhibit the growth of the less metal-tolerant plants with their roots permitted to intermingle and develop coincident rhizosphere. The hyperaccumulating ecotype of S. alfredii Hance was interplanted with non-hyperaccumulating ecotype in pots without barrier, or separated by solid barriers or mesh barriers to limit the extent of root intermingling （rhizosphere interaction）. The results showed that the biomass and Zn concentrations in the root of non-hyperaccumulating ecotype of Sedum alfredii Hance varied with different extents of root intermingling, shoot and root biomass of non-hyperaccumulating ecotype was decreased significantly, and the Zn concentration in the root of non-hyperaccumulating ecotype were increased when the roots of non-hyperaccumulating ecotype were completely intermingled or separated by mesh with hyperaccumulating ecotype.

关 键 词：东南景天 根系 锌 套种 

分 类 号：X171.5[环境科学与工程—环境科学]