The Response Of Medicinal Ingredients And Spectra Of Eucommia Ulmoides Under Nitrogen Deposition

Eucommia ulmoides (EU), one of the secondary plants to be protected in China, has highly socialand economic value. Nowadays, more and more scholars at home and abroad have drawn attention toits medicinal ingredients, such as pinoresinol diglucoside (PDG), chlorogenic acid (CA), geniposidicacid (GPA), geniposid(GP) and aucubin (AU).Considering the domestic cultivation area of EU isroughly located in the Yangtze river basin, and these areas are the most concentrated places of nitrogendeposition distribution in our country, it is of far-reaching significance to study the response of mainactive ingredients of EU to nitrogen deposition.81annual seedlings of EU were selected to simulate nitrogen deposition test and were divided3nitrogen deposition processing gradient: control (CK:0kg·hm-2·a-1), low nitrogen (LN:30kg·hm-2·a-1), medium nitrogen (MN:60kg·hm-2·a-1). The study investigated the response to simulated nitrogendeposition of EU by probing the main active components content with HPLC and the reflectancespectra using hyperspectral remote sensing technology.The main results are as following:(1) the influence of the simulated nitrogen deposition on the main medicinal components of EU:during six months，monitoring, low nitrogen treatment had a promoting effect on the accumulation ofPDG, CA, GPA and GP from the bark of EU; while medium nitrogen group showed suppression earlierand promoting later. AU in the bark was more sensitive to nitrogen treatment, and early the lownitrogen group had showed inhibitory effect. AU, CA, GPA in the leaves of EU was more sensitive tonitrogen treatment than in the bark. During the whole period, in both low and medium groups, the threecomponents were nearly subject to different levels of stress, and increasing with the concentration ofnitrogen deposition. The difference was significant. To sum up, PDG, AU, CA, GPA and GP from barkand leaves of EU had different response to the nitrogen treatments, and the difference was highbetween the treatments, changing in the seasons.(2) the influence of the simulated nitrogen deposition on the spectral reflectance of EU: comparedwith control group, the seedlings grew well under low nitrogen treatment, with the lowest spectralreflectance, and the red edge position presented a trend of “red shift”; while the spectral reflectance invisible light and near infrared band under medium nitrogen deposition was generally higher, and the “blue shift” phenomenon occurred, consequently, the growth of EU was restrained, and this inhibitoryability eliminated little by little. The difference significant spectral regions among nitrogen depositionprocessing were gradually increased with the passage of time, while in October, differences in theinfrared significantly reduced. Compared with two normalized vegetation index NDVI and gNDVI,RVI700and RVI550showed more effective function to indicate stress.