AN EFFICIENT METHOD FOR SCREENING SEED COLOR IN ETHIOPIAN MUSTARD USING VISIBLE REFLECTANCE SPECTROSCOPY AND MULTIVARIATE-ANALYSIS

Seed colour is considered as an important breeding objective in Ethiop ian mustard and other Brassica species, but its measurement is usually subjective rather than objective. For this reason we studied the pote ntial of visible reflectance spectroscopy (VRS) combined with factoria l analysis and multivariate calibration to predict seed colour in seed s of Ethiopian mustard. A total of 8331 samples were screened in the r ange 400-2500 nm with a near infra-red reflectance spectroscopy (NLRS) spectrophotometer. A common factor analysis was performed using 1148 samples and spectral data from 400 to 700 nm. It was found that four c ommon factors explained 99.9% of the variance. Three of these factors were associated with colour characteristics of the seeds. Factor 1 sep arated yellow, yellow-brown and brown seeded samples, factor 3 separat ed brown from reddish-brown samples and factor 4 separated complete ye llow from greenish-yellow samples. Calibration equations were develope d for each factor, which allowed seed colour in those samples not incl uded in factor analysis to be predicted. This study demonstrated that seed colour prediction can be incorporated into NIRS routine analysis with instruments that incorporate the visible spectral region.