Phenotyping flag leaf nitrogen content in rice using a three-band spectral index

摘要

Accurate, rapid and non-destructive measurements of rice flag leaf nitrogen content (LNC) are crucial for geneticists and breeders. To help design a less expensive, non-destructive, real-time LNC sensor, we developed a Three-Band Difference Ratio (TBDR) spectral index, TBDR (R-755, R-513, R-508). This spectral index could accurately and rapidly estimate rice LNC in a population of chromosome segment substitution lines with small variation in LNC. The model estimating LNC was validated using a leave-one-out cross-validation technique; the achieved root mean square error was 0.13% and the relative error was 4.74%. In comparison with SPAD-502plus chlorophyll meter readings and commonly used spectral indices, including GreenSeeker- and Crop Circle-based indices, TBDR (R-755, R-513, R-508) produced higher accuracy in LNC estimation.