施氮下丛枝菌根真菌对羊草化学计量特征的影响

Effects of Arbuscular Mycorrhizal Fungi on Stoichiometric Characteristics of Leymus chinensis under Nitrogen Addition

丛枝菌根真菌(AMF)能与大多数陆地植物形成共生关系,提高植物对碳(C)、氮(N)、磷(P)等营养元素的利用效率,改变植物碳氮磷化学计量特征。以禾本科牧草羊草(Leymus chinensis)为研究对象,研究对照、施氮、施AMF及施氮+AMF 4种处理对羊草碳氮磷生态化学计量特征的影响。结果表明:施AMF对羊草氮含量有显著影响,使羊草氮含量提高107%(P<0.001),碳氮比降低27%(P<0.05),氮磷比提高58%(P<0.05);施氮显著影响羊草碳氮比和氮磷比,碳氮比降低20%(P<0.05),氮磷比提高35%(P<0.05);施氮条件下,施AMF对羊草生物量和碳、氮、磷含量有显著影响,生物量显著提高154%(P<0.05),碳含量提高212%(P<0.01),氮含量提高176%(P<0.05),磷含量提高146%(P<0.05),碳氮比降低20%(P<0.05)。因此,AMF与植物根系形成的共生关系,能通过改变植物对氮素的吸收,提高氮素吸收利用效率,最终促进羊草吸收氮素。

Arbuscular mycorrhizal fungi(AMF)can form a symbiotic relationship with most land plants,improving the plant utilization efficiency of nutrients,such as carbon(C),nitrogen(N),and phosphorus(P),and altering their stoichiometric characteristics.In this present study,the effects of nitrogen addition on the stoichiometric characteristics of Leymus chinensis were explored.There were four treatments:control,nitrogen addition,AMF addition,and nitrogen integrated with AMF.The results showed that AMF addition treatment had significant effects on the nitrogen content of L.chinensis,which increased by 107%(P<0.001).Meanwhile,C∶N decreased by 27%(P<0.05),and N∶P increased by 58%(P<0.05).Nitrogen addition had significant effects on the C∶N and N∶P of L.chinensis,reduced by 20% and increased by 35%,respectively(P<0.05).AMF had remarkable effects on the biomass and the contents of C,N,and P of L.chinensis when nitrogen was added,increased by 154%,212%,176%,and 146%,respectively,while C∶N decreased by 20%(P<0.05).In conclusion,the symbiotic relationship formed by AMF and L.chinensis roots can improve the efficiency of nitrogen absorption and utilization.