Detection Of Photosynthetic Indexes Of Tomato Leaves Based On Spectral Technology

My country's area of planting tomatoes ranks third in the world,tomato plants are analyzed by the method of rapid nondestructive detection,which has a significant meaning for promoting the yeild and quality of tomatoes.Both chromaticity value and photosynthetic rate are able to reflect photosynthetic capacity indexes,the lower chromaticity value and the higher photosynthetic rate,the higher chlorophyll content,the stronger absorption of the light energy with protein,the stronger the photosynthetic capacity.So the research,with laser include fluorescence spectroscopy and hyperspectral imaging system,uses PLS to model the chromaticity value and photosynthetic rate and studies the technology of tomato's nondestructive testing.The main contents and results are as follows:(1)Measurement of physiological indexes of tomato leaves.This study select photosynthetic rate and chromaticity value as photosynthesis indexes,the equipment and measurement methods used for detecting evaluation index are described;The fluorescence and hyperspectral information of tomato leaves are collected,the composition of the laser induced fluorescence spectrum system is described in detail,the specific process of two kinds of spectral data acquisition is explained.(2)The establishment of the fluorescence spectrum model and hyperspectral model of tomato leaves'chromaticity value.The index of the model by fluorescence spectrum is R~2=0.9816,RMSEP=0.1696<RMSEC=0.1743,the residual value of prediction is within±0.3;the index of the model by hyperspectral is R~2=0.9595,RMSEP=0.4032>RMSEC=0.2743,and the residual value after prediction is basically in the range of±0.5.(3)The fluorescence spectral model and hyperspectral model of photosynthetic rate of tomato leaves are established.The evaluation index of the model by fluorescence spectrum is R~2=0.9928,RMSEP=0.2781<RMSEC=0.2805,the predicted residual value is basically in the range of±0.06,and the evaluation index of the hyperspectral model is R~2=0.9739,RMSEP=0.3374>RMSEC=0.3261,and the predicted residual value is basically in the range of±0.5.(4)Comparative analysis of fluorescence spectra and hyperspectral model detection results.For the photosynthetic rate,the R~2 of the two models are respectively equal to 0.9982and 0.9739,the absolute values of sum of residual values are respectively equal to 0.884 and1.255;For chromaticity value,the two models R~2 are respectively equal to 0.9816 and 0.9595,the absolute values of sum of residual values are respectively equal to 0.316 and 1.070.The stability of photosynthesis rate model is better than that established by chromaticity value,compared with hyperspectral imaging technology,fluorescence spectroscopy is more stable and fast in nondestructive testing of tomatoes.