近红外漫反射光谱法测定玉米秸秆体外干物质消化率

以不同生态环境、不同年份，不同品种和自交系类型、不同生长发育时期以及不同部位的600个样品中选出161份玉米秸秆为材料，应用傅里叶变换近红外光谱技术，采用偏最小二乘回归法(PLS)，通过比较不同光谱范围和光谱预处理方法，在6 101.7～5 773.8 cm-1和4 601.3～4 246.5 cm-1谱区内，建立了适合不同品种类型、不同生长发育时期和不同部位且适配范围广的近红外漫反射光谱(NIRS)测定玉米秸秆体外干物质消化率(in vitro dry matter digestion，IVDMD)的稳定校正模型。其交叉验证和外部验证决定系数(R2_cv，R2_val)分别为0.907 3和0.906 6，预测标准偏差为2.08%, 预测值与化学值间的相关系数(r)达0.956。结果表明, 近红外光谱技术可以用于快速、准确测定玉米秸秆IVDMD，该结果对青贮玉米育种过程中的秸秆材料快速鉴定和筛选具有重要的意义。

Prediction of IVDMD with Near Infrared Reflectance Spectroscopy (NIRS) in Maize Stalk

The in vitro dry matter digestion(IVDMD) in maize stalk was analyzed with 161 samples selected from 600 samples of different eco-environments,hybrids and inbred lines,development stages,and various parts of the plants in two years. The technique of near infrared reflectance spectroscopy(NIRS) and partial least square regression(PLS) were used to establish the models by comparing several preprocessing procedures and wavelength ranges.The optimal models could be obtained in the range of 6 101.7-5 773.8 cm~(-1) and 4 601.3-4 246.5 cm~(-1) by the spectral data preprocessing of the Max-Min normalization.The model is suitable for measuring various sample IVDMD.The determination coefficients of the modes were 0.907 3 and 0.906 6 for cross and external validation,respectively.The root mean square error of prediction was 2.08%,and the coefficient of correlation(r) was 0.956 between NIRS predicted and actual IVDMD in these materials.The results showed that NIRS is a simple(effective) means for measuring IVDMD in maize stalk.The results are of great value of application in screening and evaluating quality constituents of silage maize.