丛枝菌根真菌对垂穗披碱草吸收不同氮源效率的影响

Effects of Arbuscular Mycorrhizal Fungi on the Uptake of Different Nitrogen Sources in Elymus nutans

为了研究丛枝菌根真菌(AM)对垂穗披碱草(Elymus nutans)吸收不同氮源效率的影响,通过在石英砂中不接菌、接种灭活真菌和激活真菌来探讨植株对谷氨酸和硝酸铵的吸收效率,以期为优质高产垂穗披碱草新品种选育及野生种质资源的开发利用提供理论指导。结果表明:接种激活真菌处理的植株根系均受到不同程度的侵染,且侵染率随时间变化呈先增加后减少的趋势。在不同氮源条件下,接种AM真菌均能显著提高垂穗披碱草的叶绿素a、叶绿素b、总叶绿素、类胡萝卜素、总氮、总游离氨基酸、可溶性蛋白的含量和硝酸还原酶的活性(P<0.05),但对植株的叶绿素a与b的比值影响不大。当单独利用有机氮或无机氮作为氮源时,接种AM真菌能显著提高植株生物量,且在有机氮条件下效果更加明显。表明接种AM真菌有助于提高垂穗披碱草对有机氮吸收,增加牧草品质和产量。

In order to provide a theoretical basis for the new variety breeding of good quality and high yield and the exploitation of wild genetic resources, the effects of arbuscular mycorrhizal fungi （AMF） on the uptake of glutamie acid and ammonium nitrate in Elymus nutans were investigated. The results indicated that all inoculated roots were colonized, and colonization rate increased firstly and then decreased. Applica- tion of AMF could improve the contents of chlorophyll, carotenoid, total nitrogen, total free amino acid, soluble protein and the activity of nitrate reductase under different nitrogen sources, whereas had hardly effect on the chlorophyll a/h rate of Elymus nutans. Adding active fungi could improve the biomass of Elymus nutans when organic nitrogen or inorganic nitrogen was single nitrogen resource, and the effects of organic nitrogen were far better than inorganic nitrogen. In conclusion, application of AMF is helpful to improve the biomass and forage aualitv of Elvmus nutans.