基于Raman和FTIR揭示避雨栽培甜樱桃叶片光合色素变化的光谱学分析

为提高甜樱桃果实的品质和产量,中国南方地区普遍采用了避雨栽培甜樱桃果树来避免其坐果率低、落果以及果实畸形等问题,但同时也导致了其光合作用受到影响.植物或藻类中的叶绿素和类胡萝卜素等光合色素在光收集和介导对各种内源性刺激的应激反应中起着不可替代的作用.为便捷快速检测果树光合作用中叶片的光合色素变化,采用拉曼光谱(Rama...

Spectral Analysis of Changes in Photosynthetic Pigment Composition in Leaves of Sweet Cherry Tree Under Rain-Shelter Cultivation Based onRaman and FTIR

To improve the of quality and yield of sweet cherry fruits,sweet cherry trees were cultivated under rain-shelter to avoid the problems of low fruit setting rate,falling fruit and fruit malformation in southern China.Sweet cherry trees under rain-shelter cultivation had an obvious negative effect on photosynthesis.In both plants and algae,photosynthetic pigments such as chlorophylls and carotenoids play irreplaceable roles in light harvesting and mediating stress responses to a variety of endogenous stimuli.This research aimed to detect changes of photosynthetic pigments in leaves that affect photosynthesis of fruit trees quickly and conveniently.The experiment took sweet cherry leaves in two different cultivation pattern,open-field and rain-shelter cultivation,as the research objects,and determined its Raman spectrum in the range of 200~3500 cm^-1.The analysis is performed,and the characteristic peaks are calibrated and designated from three wave number bands of 400~800,800~1250 and 1250~1650 cm^-1.According to the Raman spectrum characteristic value,it is concluded that the sweet cherry leaves have a relatively small Raman scattering.Sensitivity is mainly concentrated in the 500~1700cm-1 band.The analysis of Raman spectrum in the range of 960~1800 cm^-1found that characterizes the carotenoids(lycopene,β-carotene and lutein)mainly contains 4 main peaks,which are 1526,1157,1005 and 960 cm^-1,the Raman intensity of leaves of sweet cherry tree under open-field cultivation is significantly lower than that of rain-shelter cultivation.1157 and 1526 cm^-1are also the Raman spectrum characteristic peaks of chlorophyll.Overall analysis shows that photosynthetic pigment content in leaves of sweet cherry under open-field cultivation is lower than that of under rain-shelter cultivation.The characteristic spectral lines of 1157,1520 and 1526 cm^-1correspond to symmetrical stretching vibrations of C—C single bond and C C double bond,and their relative strengths can be used as the basis for judging the content of cellulose,carotenoids and chlorophyll in sweet cherry leaves.Fourier transform infrared spectroscopy(FTIR)characterizes that the vibration peak position and vibration intensity of chlorophyll are weak,the vibration coupling is complex and difficult to identify.The second derivative treatment of the infrared spectrum of the chemical composition in sweet cherry leaves was used to derive the peak position and enhance the resolution of the spectrum.The characteristic peaks ofβ-carotene at 1437 and 1551 cm^-1are obvious.Compared to rain-shelter cultivation,sweet cherry leaves showed lower absorbance at these two characteristic peaks,indicating that the content ofβ-carotene in leaves sweet cherry tree under open-field cultivation is less than that of rain-shelter cultivation.These findings provide the theoretical basis for the spectroscopy research of photosynthetic pigments in plant leaves under different cultivation pattern.