Characteristics Of Spectra And Chlorophyll Fluorescence Induced Kinetics Of Phyllostachys Pubescens Stems Under The Rapid Growth Stage

This study investigated characteristics of stems of Phyllostachys pubescen, with rapid growthstages(10-60d). During the study, we used chlorophyll fluorescence induced kinetics (FIK) andpulses-amplitude-modulation PAM)fluorescence to measure the content of pigment,reflectanceand fluorescence parameters in vitro. Preliminary research results are as follows:The contents of Chl a, Chl b and carotenoids in stems increased with the development ofP.pubescen, the highest content is at60days. While the contents of Chl a/b increased and thendecreased with the age increased, the reduced amplitude is small, and the ratio basically stable at around2.0after30days.Via comparison between the raw spectral data and reflectance spectrum with1th order derivativethe result showed that,the reflectance spectral curves of stems under rapid growth stage had almost thesame trendency. With the development period to advance, there were two absorption trough in the500nm and680nm, and the reflection spectra exhibit decreased gradually.The value of the reflectancespectrum parameters (GNDVI, PSDNa, PSSDa, PSSDb, PSDNb, mND705, mSR705, CRI1, ARI1and PRI) were allincreased with the growth of the stems, however, the value of NPCI, SIPI and Rred/Rgreen was decreased. Thechange of Sred was mainly raised under the rapid growth stage. We also evaluate the relationship betweenreflectance spectra characteristics and pigment contents, The result showed that the reflectance spectrumparameters, such as GNDVI, PSSRa, PSSRb, PSSRc, PSNDa, PSNDb, PSNDc, NPCI, mSR705, mND705, Dλred and λred,were significantly (P <0.01) correlated with the content of chlorophyll a,chlorophyll b and carotenoids. Thecorrelation between PSSDa and Chl a reached extremely significant level, meanwhile CRI2、λredreached extremely significant level with Car, the situation was the same with Chl b and PSSDb, Chl a/band Chl a/b Rch、SIPI (P <0.01).Chlorophyll fluorescence can reflect the photosynthetic characteristics of stems. With thedevelopment period advanced, the opening of the reaction center and the numbers of per unitareareaction of center were lower,but the maximum photochemical efficiency in energytransfer was gradually increased. Weanalyzed chlorophyll FIK of the stems under the rapid growthstage, The results of the PAMfluorescence show that, fluorescence intensityand and non photochemicalquenching coefficient gradually decreased, while the relative electron transport rate and photochemical quenching coefficient gradually increased with the developmental period advanced, the photosynthesisability.of the stems reinforced.