Abstract:
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 One-year 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 by 5.64%, 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.