AM真菌和无机磷对油茶苗磷吸收和培养土壤磷组分的影响

Effects of AM Fungi and Inorganic Phosphorus on Phosphorus Uptake and Grown Soil Phosphorus Fraction of Camellia oleifera Seedlings

[目的]探究不同无机磷水平下丛枝菌根真菌对油茶苗磷素吸收的促进作用,为接种丛枝菌根真菌提高油茶磷效率的研究提供理论依据。[方法]以1年生油茶苗为宿主植物,接种幼套近明球囊霉(Claroideogolmus etuicatum)和施KH2PO4(0、10、50、100 mg·kg^(-1)),探究接种AM真菌和无机磷对油茶磷吸收和土壤磷组分的影响。[结果]在不施磷(0 mg·kg^(-1))、低磷(10 mg·kg^(-1))、中磷(50 mg·kg^(-1))和高磷(100mg·kg^(-1))条件下,菌根化油茶苗磷含量均显著高于未菌根化,地上部分别提高了5.64%、8.14%、14.28%、5.79%,根系磷含量分别提高了12.85%、20.01%、19.63%、18.09%。接种AM真菌处理、施加无机磷处理及其两者交互作用下对土壤全磷含量、有效磷含量以及有机磷含量的影响均极显著。接种幼套近明球囊霉极显著降低了土壤中Al-P、Fe-P、Ca-P、O-P 4种磷形态含量。在低磷条件下,接种幼套近明球囊霉显著增加了油茶苗叶片和根系中Pht1;1基因的表达;在中磷、高磷条件下,接种幼套近明球囊霉则降低了油茶叶片和根系中Pht1;1基因的表达。[结论]AM真菌可改变油茶苗土壤中磷形态,促进植株对土壤中有效磷的吸收效率,并参与调控油茶植株中Pht1;1基因的表达。该试验结果为微生物菌肥提升油茶苗对土壤磷素吸收效率和减少磷肥施入量提供科学依据,同时促进我国油茶产业持续健康发展。

[Objective]To investigate the promotion of phosphorus uptake in Camellia oleifera seedlings by mycorrhizal fungi at different inorganic phosphorus levels,and provide a theoretical basis for the study of inoculation with mycorrhizal fungi to enhance phosphorus efficiency of C.oleifera seedlings.[Method]Oneyear old C.oleifera was used as the host plant,and young sets of Claroideogolmus etuicatum were inoculated with KH2PO4(0,10,50,100 mg·kg^(-1)).The effects of inoculation with AM fungi and inorganic phosphorus on phosphorus uptake and grown soil phosphorus fraction of C.oleifera seedlings were investigated.[Result]Under the conditions of no(0 mg·kg^(-1)),low(10 mg·kg^(-1)),medium(50 mg·kg^(-1))and high(100 mg·kg^(-1))phosphorus application,the phosphorus content of mycorrhization C.oleifera seedlings was significantly higher than that of non-mycorrhization.The above-ground phosphorus content increased by5.64%,8.14%,14.28%and 5.79%,respectively,and the phosphorus content of seedling root system increased by 12.85%,20.01%,19.63%and 18.09%,respectively.The effects of inoculation with AM fungal treatment,application of inorganic phosphorus treatment and their interaction on soil total phosphorus content,effective phosphorus content and organic phosphorus content were highly significant.Inoculation with C.etuicatum significantly reduced the content of four phosphorus forms,Al-P,Fe-P,Ca-P and O-P in the soil.Under low phosphorus conditions,inoculation of C.etuicatum significantly increased the expression of Pht1;1 gene in leaves and root systems of the seedlings;under medium and high phosphorus conditions,inoculation of C.etuicatum decreased the gene expression of Pht1;1 gene in leaves and root of C.oleifera seedlings.[Conclusion]AM fungi can alter phosphorus morphology in C.oleifera grown soil,promote the uptake efficiency of effective phosphorus in soil by plants,and participate in regulating the expression of Pht1;1 gene in C.oleifera.The results of this study provide a scientific basis for microbial fertilizer to improve soil phosphorus uptake efficiency of C.oleifera seedlings and reduce phosphorus fertilizer application,which promotes the healthy and sustainable development of C.oleifera industry in China.