توصيفگر ها :
سنجش از دور , طيف سنجي , عارضه جذب , مدل سازي , متابوليت ثانويه , طيف سنجي مادون قرمز
چكيده انگليسي :
Secondary metabolites have high ecological and economic value. Measuring the amounts of these metabolites in plants through laboratory analysis is time-consuming and expensive. On the other hand, in laboratory method, sampling points cannot be generalized to a wide area of pastures that have climate, topography and soil diversity. Therefore, the present study was carried out with the aim of measuring the potential of PRISMA hyperspectral data in order to estimate the amount of secondary metabolites in species of western Isfahan province at landscape scale. The concentration of secondary metabolites and spectral signatures were extracted from leaves of 42 bases of medicinal plants including A. adscendens, A. verus, D. mucronata, A. aphylla and P. olivieri using laboratory methods and spectroscopy in the range of 350 to 2500 nm. Essential oil compounds, total phenol, flavonoid, anthocyanin, chlorophyll, carotenoid, total chlorophyll and percentage of antioxidant activity were investigated in medicinal species in Isfahan province.The results of the analysis of essential oil compounds with GC/MS led to the identification of the highest number of compounds (25 compounds) in A. adscendens and the lowest number (12 compounds) in D. mucronata. The most abandoned compounds in A. adscendens was Phthalate (59.88%), in A. verus was Phytol (38.02%), in D. mucronata was Hexanoic acid (32.05%) and in P. olivieri belonged to β-cubebene (30.94%). The results of secondary metabolites analysis showed the highest content of total phenol (18.24 mgGAE/gDW) in D. mucronata, the highest content of flavonoid (3.85 mgQ/gDW) in A.verus, the highest amount of anthocyanin (0.23mg/gDW) was found in P. olivieri and the highest total chlorophyll content (0.27 mg/gDW) was in A. adscendens. Carotenoids were the highest in A. adscendens and D. mucronata (0.03 mg/gDW) and were not significantly different, and the highest antioxidant activity (71.36%) was observed in A. verus. FTIR analysis in A. adscendens and A. verus showed alkyne, alkene, alcohol, ester, phenol, aldehyde, vinyl ether, carboxylic acid and in D. mucronata showed alcohol, phenol and alkane. Phenol, was reported in all species as well as A. aphylla (Aliphatic amine, aromatic compounds, alkane, alcohol, alkene and phenol) and P. olivieri (Alkyne, alcohol, amine, phenol, carboxylic acid, alkene and nitro compounds). The representative bands of secondary metabolites were identified by establishing a relationship between the concentration of secondary metabolites and all spectral bands with the PLSR method. Then, the map of spatial changes of secondary metabolites was prepared using BRNN, RF, GAM and GLM models. The highest coefficient of explanation was obtained in the estimation of phenol concentration with RF (0.955), anthocyanin concentration with BRNN (0.595), flavonoid concentration with GLM (0.759) and antioxidant percentage with GLM (0.631). The findings showed that satellite hyperspectral data have a high ability to estimate secondary metabolites at the landscape scale and can be used as a complement to laboratory methods in management of rangeland medicinal plants.
