采用盆栽实验，比较了低磷（0.05 mmol·L^-1）和正常施磷（0.50 mmol·L^-1）下接种土生空团菌（Cenococcum geophilum Fries）和豆马勃属菌(Pisolithus sp.)以及未接菌的薄壳山核桃〔Carya illinoinensis (Wangenh.) K. Koch〕幼苗在净光合速率、干质量、营养元素吸收以及土壤酶活性的差异。结果显示：低磷条件下，土生空团菌和豆马勃属菌的幼苗菌根侵染率分别为39.9%和35.5%；正常施磷条件下，这2种真菌的幼苗菌根侵染率分别为41.4%和31.9%。总体上看，缺磷会抑制幼苗光合作用，减少干质量以及叶中全氮、全磷和全钾含量；接菌处理促进了幼苗光合作用，增加了干质量以及根、茎、叶中全氮、全磷和全钾含量。低磷条件下，接种豆马勃属菌对幼苗光合作用和干质量增加的提升效果显著优于接种土生空团菌，接种土生空团菌对幼苗营养元素吸收的提升效果总体优于接种豆马勃属菌。低磷条件下，接菌处理提高了土壤中β-葡萄糖苷酶、N-乙酰-β-葡萄糖苷酶和碱性磷酸酶活性，降低了亮氨酸氨基肽酶活性，且接种豆马勃属菌对土壤酶活性的提升效果优于接种土生空团菌。综合分析认为，外生菌根真菌对薄壳山核桃幼苗在低磷条件下的磷吸收和生长具有明显促进作用，不同菌种对薄壳山核桃幼苗生长和土壤酶活性的影响存在差异，在提高磷利用效率和宿主植株干质量方面表现出不同的优势。

The differences in net photosynthetic rate, dry mass, nutrient element uptake, and soil enzyme activity of Carya illinoinensis (Wangenh.) K. Koch seedlings inoculated with or without Cenococcum geophilum Fries and Pisolithus sp. under low phosphorus (0.05 mmol·L^-1) and normal phosphorus application (0.50 mmol·L^-1) were compared by pot experiment. The results show that under low phosphorus condition, the mycorrhizal colonization rates of seedlings inoculated with C. geophilum and Pisolithus sp. are 39.9% and 35.5% respectively; under normal phosphorus application condition, the mycorrhizal colonization rates of seedlings inoculated with these two fungi are 41.4% and 31.9% respectively. Overall, phosphorus deficiency inhibits photosynthesis of seedlings， decreases dry mass and contents of total nitrogen, total phosphorus and total potassium in leaves, and the inoculation treatment promotes photosynthesis of seedlings, and increases dry mass and contents of total nitrogen, total phosphorus and total potassium in roots, stems and leaves of seedlings. Under low phosphorus condition, inoculation with Pisolithus sp. has a significantly higher promoting effect on photosynthesis and dry mass increment of seedlings than inoculation with C. geophilum, but inoculation with C. geophilum has a higher promoting effect on nutrient element uptake of seedlings than inoculation with Pisolithus sp. in general. Under low phosphorus condition, inoculation treatment increases the activities of β-glucosidase, N-acetyl-β-glucosidase, and alkaline phosphatase in soil, but reduces the leucine aminopeptidase activity, and inoculation with Pisolithus sp. has a higher promotion effect on soil enzyme activity than inoculation with C. geophilum. The comprehensive analysis suggests that ectomycorrhizal fungi have an evidently promoting effect on phosphorus uptake and growth of C. illinoinensis seedlings under low phosphorus condition, different fungal species exhibit distinct effects on growth of C. illinoinensis seedlings and soil enzyme activity, and show different advantages in improving phosphorus utilization efficiency and dry mass of host plant.