Haploid differentiation in maize kernels based on fluorescence imaging

Abstract

Abstract A new fluorescence‐based method for inbred haploid differentiation in maize kernels was developed by utilizing the R1‐nj colour marker in combination with fluorescence microspectroscopy and imaging. Seven inbred lines with varying R1‐nj expression were used in this study. The fluorescence response of the diploid kernels at the embryonic dye spot was shown to simultaneously exhibit lower intensity and occur at a higher wavelength than the fluorescence of the dye‐lacking haploid embryos. Intensity and area thresholds were applied to fluorescence images to sort the haploids from mixed sample populations, and sorting efficiencies of greater than 80% were achieved in all seven inbred lines (with values greater than 90% for five lines). The potential for high‐throughput sorting when fluorescence imaging is combined with existing technologies for seed handling as well as high sorting efficiency may make fluorescence a viable and promising alternative to current sorting methods for some inbred lines.