摘要
以豆科植物紫花苜蓿为试验材料,应用三室(供体室-间隔室-受体室)培养系统,研究在供体和受体紫花苜蓿根系之间菌丝网络形成的时间效应以及间隔室中不同植物对菌丝网络建成的介导作用。第一个试验在供体和受体植物生长8、10、12、14周之后进行收获以检验菌丝网络形成的时间效应;第二个试验则在间隔室分别种植紫花苜蓿、羊草和独行菜,以考察菌根依赖性不同的植物对菌丝网络形成的介导作用。试验结果显示:(1)接种丛枝菌根真菌的供体紫花苜蓿根系能够形成良好的菌根共生,其外延菌丝可穿过尼龙网和间隔室侵染受体植物根系;植物生长8周后,在受体植物根系检测到菌根侵染,证实供体和受体植物间形成了根间菌丝网络;10周后,尽管供体室和受体室植物的侵染率已无差异,但二者的生物量和地上部磷浓度差异却加大,表现出菌丝网络对植物种内竞争影响的不对称性。(2)试验条件下,不同介导植物对受体植物的菌根侵染及生物量均无明显影响,但显著降低了供体植物生物量和地上部磷浓度;间隔室无介导植物或种植独行菜时,受体植物地上部和根系生物量显著低于供体植物,而当介导植物为紫花苜蓿和羊草时,受体和供体植物生物量无显著差异。研究表明,植物根间菌丝网络的形成受时间和介导植物的影响,同时也具有调节植物间资源分配和植物相互作用的功能。
In the present study,a three compartment-cultivation system was designed to investigate the development of common mycorrhizal network as mediated by different plant species and also the time effects.Medicago sativa as test plant was grown in two outer compartments,one as donor compartment receiving AM fungal inoculum and another as receiver compartment indicating development of hyphal network.In the first experiment,plants were harvested at 8,10,12 and 14 weeks after planting to test the time effects;while in the second experiment,the middle compartment was left for mediating plants,M.sativa,Leymus chinensis or Lepidium spetalum,which are known to exhibit different mycorrhizal dependency.The experimental results indicated that：（1）At 8 weeks after planting the external hyphae from donor plants penetrated the nylon meshes separating different compartments and colonized receiver plants.At 10 weeks after planting,mycorrhizal colonization rate of receiver plants reached the same level as that of donor plants.However,the plant biomass and shoot P concentrations were significantly lower for receiver plant,indicating asymmetric competition between different plants bridged by hyphal network.（2）Under experimental conditions,different plants in the middle compartment showed no significant effects on mycorrhizal colonization and biomass of receiver plants,but significantly decreased plant biomass and shoot P concentrations of donor plants.In case of L.spetalum or no plants in the spacer compartment,both shoot and root biomass of receiver plants were significantly lower than those of donor plants;while in case of M.sativa and L.chinensis,there were no significant differences in plant biomass between donor and receiver plants.The study demonstrated that both time and mediating plants are important factors influencing development of hyphal network between plant roots,and the established hyphal network could redistribute resources between plants and stimulate plant interactions.
出处
《西北植物学报》
CAS
CSCD
北大核心
2013年第1期154-161,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
中国科学院知识创新工程重要方向性项目(KZCX2-YW-BR-17)
国家自然科学基金面上项目(41071178)
城市与区域生态国家重点实验室自主方向项目(SKLURE2008-1-03)
关键词
丛枝菌根
菌丝网络
介导植物
生态功能
arbuscular mycorrhiza
hyphal network
mediating plant
ecologcal function
