丛枝菌根真菌对宁夏枸杞生长和氮代谢的影响

丛枝菌根真菌（AMF）在促进植物生长和矿质营养吸收方面发挥重要作用。采用盆栽试验，探索了不同浓度氮处理（0、1、15 mmol NH₄NO₃）下丛枝菌根真菌对宁夏枸杞生长、光合作用和氮代谢的影响。结果表明，AMF对宁夏枸杞的侵染率随施氮量增加而增加，3种浓度氮处理下AMF侵染率分别为29.32%、43.93%和62.81%。施氮和接种AMF均提高宁夏枸杞叶片叶绿素含量和光合速率，提高根系和叶片全氮含量，提高根系硝酸还原酶活性（NR）及叶片谷氨酰胺合成酶（GS）活性；1 mmol NH₄NO₃处理能够促进宁夏枸杞生物量累积，提高叶片总叶绿素含量和NR活性；15 mmol NH₄NO₃处理能够提高宁夏枸杞叶片和根系NH₄⁺含量，提高根系NH₄⁺百分比，降低叶片NO₃^-百分比。表明AMF能够通过改善氮代谢及提高光合能力，促进宁夏枸杞生长。

Effects of Arbuscular Mycorrhizal Fungi on the Growth and Nitrogen Metabolism of Lycium barbarum

Arbuscular mycorrhizal fungi(AMF)play important roles in promoting plant growth and mineral nutrition absorption.A pot experiment was conducted to explore the effects of AMF on the growth,photosynthesis,and nitrogen metabolism of Lycium barbarum under different nitrogen treatments(0,1 and 15 mmol NH₄NO₃).The results showed that the colonization rate of AMF increased with the increase of nitrogen application content,and the colonization rates of AMF in three treatments were 29.32%,43.93%and 62.81%,respectively.The chlorophyll content,photosynthetic rate,total nitrogen content of leaf and root,nitrate reductase(NR)activity in root and glutamine synthase(GS)activity in leaf of L.barbarum increased under nitrogen application and AMF inoculation.The biomass,total chlorophyll content and NR activity in leaf increased under 1 mmol NH₄NO₃ treatment.The content of NH₄⁺in leaf and root,the proportion of NH₄⁺ in root increased under 15 mmol NH₄NO₃ treatment while the proportion of NO₃^-in leaf decreased.The results indicated that AMF could promote the growth of L.barbarum by improving nitrogen metabolism and photosynthesis.