初期稻叶瘟病害的叶绿素荧光光谱分析  

Chlorophyll Fluorescence Spectra Analysis of Early Rice Blast

作　　者：周丽娜[1,2] 程树朝 于海业[1] 张蕾[1] 

机构地区：[1]吉林大学工程仿生教育部重点实验室,长春130025 [2]吉林农业大学工程技术学院,长春130118

出　　处：《农业机械学报》2017年第2期203-207,共5页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家高技术研究发展计划(863计划)项目(2013AA103005-04)

摘　　要：为了实现稻叶瘟病害的早期、快速检测,对稻叶瘟病害初期水稻叶片的叶绿素荧光光谱变化进行分析,建立光谱诊断模型。将稻梨孢接种于水稻叶片,分别在接种前期(0 h)、潜育期(48 h)和病斑初现期(7 d)3个时段采集水稻叶片的叶绿素荧光光谱。分析3个时段光谱变化特征,并利用Savitzky-Golay平滑(SG)和一阶导数变换(FDT)对光谱进行预处理。利用高斯拟合法(GFF)分别对原始光谱、SG平滑光谱和SG-FDT光谱提取各波段光谱特征向量。将试验样本划分为建模样本和检验样本,以病害初期的3个时段作为稻叶瘟病害的等级指标,分别采用全波段光谱特征向量和组合波段光谱特征向量,对3种预处理光谱利用建模样本建立稻叶瘟病害的支持向量分类(SVC)模型,对比4个经典核函数,并利用检验样本对模型进行检验。结果表明,蓝绿光区域、红光与远红光区域荧光随初期稻叶瘟病害程度的变化而变化,SG-FDT光谱的GFF-SVC(PLOY)模型对3个时段病害的分类准确率最高,且原始光谱、SG光谱、SG-FDT光谱的不同波峰位及其组合对稻叶瘟病害的识别效果不同。In order to detect rice blast rapidly and accurately,chlorophyll fluorescence spectra of early rice blast were analyzed on leaf level,and the identification models of rice blast were established. Rice leaves were inoculated with rice pear spore first,and chlorophyll fluorescence spectra were achieved respectively at three stages of inoculation before（ 0 h）,gley period（ 48 h） and disease spots early appearance（ 7 d）. Meanwhile,variation characteristics of chlorophyll fluorescence spectra at three stages were analyzed,Savitzky-Golay（ SG） and the first derivative transform（ FDT） were applied to reduce the noises and obtain the characteristics of chlorophyll fluorescence spectra. Then the method of Gaussian function fitting（ GFF） was used to achieve the dimension reduction on spectral information,and multiple feature vectors of each band were extracted. Furthermore,the spectral data were divided into calibration set and validation set. Taking three stages of early disease as rice blast levels,and comparing four classic kernel function,support vector classification（ SVC） models were established respectively with full bands feature vectors and composite bands feature vectors based on calibration set,and the models were tested with validation set. The results indicated that chlorophyll fluorescence spectra of blue green region,red and far-red region were changed with the change of severity of early disease,GFF-SVC model with SGFDT pretreatment for three stages disease had the highest classification accuracy rate,and the recognition results of different bands combination of primary spectrum, SG spectrum, SG-FDT spectrum were different for rice blast.

关 键 词：初期稻叶瘟 高斯拟合 支持向量分类机 叶绿素荧光光谱 

分 类 号：S123[农业科学—农业基础科学] S435.111.41