SPAD及FT-NIR光谱法快速筛选白三叶种质蛋白质性状

白三叶营养丰富,蛋白质含量高,是最重要的牧草之一.文章对SPAD及FT-NIR光谱法筛选白三叶种质蛋白质性状进行了探讨.采用ChlorophyIl Meter SPAD-502,测定白三叶叶片SPAD值,从而评估其蛋白质含量.在营养生长期内,叶片蛋白质含量与SPAD值呈正相关(y=0.422x+4.984,R2=0.737);在开花期内,两者之间呈负相关(y=-0.345x+37.50,R2=0.711).应用傅里叶变换近红外(FT-NIR)光谱技术,用偏最小二乘法建立了白三叶蛋白质的预测模型,并对模型进行了交叉验证和外部验证.结果表明,用NIRs法得到的预测值与用凯氏定氮法得到的测定值间的交叉验证决定系数Rcv2为0.904,交叉检验标准误差RMSECV为0.988(%DM),外部验证的相关系数为0.987.所建立的近红外模型具有良好的准确性和预测能力.FT-NIR法较SPAD法能更准确的评估白三叶蛋白质状况.NIRS作为一种白三叶粗蛋白质快速分析的技术是可行的,在白三叶蛋白质品质育种中,可快速进行种质资源筛选,提高育种效率.

Rapid Selection of White Clover Germplasms' Crude Protein Traits by SPAD and Fourier Transform Near-Infrared Reflectance Spectroscopy

White clover is one of the most important forages in the world, with high nutritive value and crude protein content. Crude protein traits of white clover germplasms was selected using SPAD and near infrared reflectance spectroscopy. The SPAD value was measured by Chlorophyll Meter SPAD-502, and was used to evaluate the crude protein of white clover. In the vegetative period, there was a positive relationship between SPAD value and foliar protein content (y=0.422x+4.984， R2=0.737), but in the flowering period, there was a negative relationship between the two indexes (y=-0.345x+37.50， R2=0.711). Crude protein content of white clover germplasms was predicted using near infrared reflectance spectroscopy with PLS regression and the model was validated by cross validation and external validation. The results showed that the correlation coefficient of cross validation, the RMSECV, and the correlation coefficient of external validation are 0.904, 0.988%, and 0.987, respectively. NIRS model of white clover crude protein content has good accuracy and precision. FT-NIRS was more accurate than SPAD. NIRS is feasible as a rapid analysis method, and can be used in the selection and breeding of white clover germplasms to improve the breeding efficiency.