毛竹出笋后快速生长期茎秆色素含量与反射光谱的相关性

Correlation between pigment content and reflectance spectrum of Phyllostachys pubescens stems during its rapid growth stage

为了探讨毛竹出笋后快速生长期茎秆色素含量与反射光谱特性间的相互关系,测定了毛竹茎秆在快速生长期内的色素含量与反射光谱参数,并对两者进行了相关性分析。结果表明:(1)在毛竹出笋后快速生长期内,随着茎秆不断生长,叶绿素a、叶绿素b和类胡萝卜素含量也随之增加,在60 d时含量最高。(2)反射光谱参数GNDVI、PSDNa、PSSDa、PSSDb、PSDNb、mND705、mSR705、CRI1、ARI1和PRI等均随着茎秆生长而增加,NPCI、SIPI和RGI则随生长而降低;Sred随着茎秆生长基本呈现出不断增大的趋势。各参数在20 d到30 d时的变化均达到极显著水平(P<0.01)。(3)GNDVI、PSSRa、PSSRb、PSSRc、PSNDa、PSNDb、PSNDc、NPCI、mSR705、mND705、CRI2、PRI、Dλred和λred等反射光谱参数与叶绿素a、叶绿素b和类胡萝卜素含量之间的相关性均达到极显著水平(P<0.01),其中PSSRb、mSR705、CRI2、PRI、ARI1和ARI2与叶绿素a、叶绿素b和类胡萝卜素含量之间的相关性高于或接近0.9,说明毛竹出笋后快速生长期反射光谱特征及其参数可用来估算叶绿素和类胡萝卜素含量,并为利用反射光谱监测其生长趋势提供了可能。

Phyllostachys pubescens,one of the most important bamboo plants in the world,is widely distributed and planted in China.Due to its rapid growth feature,long growth period and high photosynthetic efficiency,this plant has high environmental and economic value.It has been reported that the photosynthetic pigment content and its reflectance spectrum was closely related to leaf growth process of P.pubescens,and a model of reflectance spectrum was established for monitoring the plant growth.The stem of P.pubescens has abundant pigments.However,to our knowledge,no study has been reported on the relationship between reflectance spectrum characteristics and pigment contents in the stems of the plant.So we tested the pigment contents and reflectance spectrum parameters in the stem and examined its correlations.The results showed that:(1) The content of chlorophyll a,chlorophyll b and carotenoids increased with the stem growth under its rapid growth stage,and the content of these pigments reached the highest level after 60 days,(2) The value of the reflectance spectral parameters(GNDVI,PSDNa,PSSDa,PSSDb,PSDNb,mND705,mSR705,CRI1,ARI1 and PRI) increased with the growth of the stems but the value of NPCI,SIPI and RGI decreased.The change of Sred was mainly raised under the rapid growth stage.The value of those parameters was significantly changed from 20 days to 30 days.(3) The reflectance spectrum parameters,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.The correlation coefficients between reflectance spectral parameters(PSSRb,mSR705,CRI2,PRI,ARI1 and ARI2) and pigment(chlorophyll a,chlorophyll b and carotenoid) content were higher and near to 0.9,indicating that these reflectance spectral parameters can be used to evaluate the content of chlorophyll and carotenoids.