不同氮磷水平下AM真菌对棉花的侵染率及氮磷含量的影响

在不同的氮肥和磷肥水平下,采用无土栽培法研究AM真菌Glomusintraradices对棉花根的侵染率,以及棉花植株对氮磷的吸收情况。结果表明,高浓度的氮素有利于Glomus intraradices与棉花形成共生体,当氮肥为100.00 mmol/L时,Glomus intraradices对棉花根系的侵染率最高,达到65.09%;在接种Glomus intraradices的情况下,不施氮肥的棉花植株,其茎叶含磷量显著高于施用氮肥的植株;而棉株茎叶中的含氮量却随着施氮水平的提高而增加,这表明高浓度的氮素不利于Glomus intraradices棉花共生体对磷元素的吸收,却有利于其对氮元素的吸收;而低浓度的磷素形态有利于Glomus intraradices的菌丝对棉花的侵染,以0.025 mmol/L的磷肥水平,侵染率最高。

Effects of Different N and P Concentration on Cotton AM Symbiosis and Its Absorption of N and P

At different concentrations of N and P,colonization rate of Glomusintraradices（AM fungi）in hostcotton rootsand the absorption of N and P in cotton shoots were measured . The results showed that the high concentration of N was benefit to formation of cotton and Glomusintraradicessymbiosis,especially the colonization rate was65.09% at100 mmol＆#183;l-1.The cotton shootwithoutN treatmentshowed a significantly higherP contentthan thatwith N treatment.In addition,the N absorption in cotton shootsincreased with the levelofN treatment, The above mentioned showed that a high concentration of N was advantage to the symbiosis for N absorption, but disadvantage for P absorption. Lowconcentration of P wasconducive to hypha ofGlomusintraradicesto infectthe cotton root,particularly 0.025 mmol＆#183;l-1 ofP was the bestconcentration.