接种AM真菌对玉米生长的影响及叶片全氮含量的高光谱估测

为了快速、准确测定玉米叶片中的全氮含量,实现利用高光谱遥感技术对微生物修复作用下氮元素的监测,现设接种丛枝菌根(M)和不接种菌根的对照组(CK),分别测定2个处理下叶片理化参数和光谱反射率数据,研究接种AM真菌对玉米生长的影响并采用逐步回归分析法建模反演叶片全氮含量。结果表明:接种AM真菌可提高不同叶位的叶片全氮、全磷、全钾及叶绿素含量,同时显著提高玉米的生物量和叶片含水率;不同的处理组中全氮含量对不同特征参数的相关性显著情况相同,但相关系数有所差异;2个处理均使用逐步线性回归法,以筛选出的9个极显著相关的光谱特征参数为自变量,对玉米叶片氮含量建模。其中,CK中模型决定系数R2最高可达0.8361,M组中模型的决定系数最高可达0.893,可以较好地估测玉米叶片全氮含量。

EFFECT OF INOCULATION WITH AM FUNGI ON MAIZE GROWTH AND HYPERSPECTRAL ESTIMATION OF TOTAL NITROGEN CONTENT IN MAIZE LEAVES

In order to quickly and accurately determine the total nitrogen content in maize leaves and monitor the nitrogen element content under microbial remediation by hyperspectral remote sensing technology, two levels of AM fungal treatment were set up, with(M) and without (CK) arbuscular mycorrhizal Fungi inoculated. The physicochemical parameters and spectral reflectance data of leaves under the two treatments were measured respectively, and the effects of AM fungi inoculation on maize were studied. Stepwise regression method was used to model and retrieve the total nitrogen content of leaves. The results showed that inoculating AM fungi could increase the contents of total nitrogen, total phosphorus, total potassium and chlorophyll in leaves at different leaf positions, and significantly increase the biomass and leaf water content of maize. The correlation of total nitrogen content in different treatments was similar to that in different characteristic parameters, but the correlation coefficients were different. The stepwise linear regression method was used to estimate the nitrogen content of maize leaves by using the nine extremely significant spectral parameters as independent variables. Among them, the model determination coefficient R2 in CK was up to 0.8361, and the determination coefficient of M model was up to 0.893, which could estimate the total nitrogen content of maize leaves.