Grain quality is one of the most important features of rice. Grain-controlling genes are difficult to find, because grain quality is regulated by quantitative trait loci (QTLs). To identify the genes involved in the control of grain size, shape, and color, we screened rice FOX Arabidopsis mutants showing seed abnormalities. Identified genes could help us to breed high-yielding, high-quality rice cultivars.
We developed a unique method for isolating mutants. About 30 T2 rice FOX seeds of each line are placed into each well (8-mm diameter) of a 70-well plastic plate. The plate is sealed with adhesive PCR film (Abgene, UK) and scanned by flatbed scanner at 3200 dpi. Seed morphology in the JPEG images is analyzed with WinSEEDLE software (Regent Instruments Inc., Canada). The WinSEEDLE data are analyzed statistically and uploaded to a database. We identified approximately 850 mutants from 14 000 rice FOX lines with this method.
The parameters for WinSEEDLE analysis were as follows. Seeds were identified as between 400 and 3000 in pixels in extent. Seed color was an RGB value of EAE6BF, C2C073, EDDFA4, E3D89E, C8AB71, B89149, BFA364, 917240, A97A36, 9E692B, 8F602E, 855F3A, AD763A, 8F6032, A17D4A, 895A30, 4D312F, 5B4137, 514235, 5F472F, 4C3A3F, 3F3536, 574C49, or 4A383A. Background color was FFFFFF, 1355CB, AAAEB4, DAE0EC, F1E9E1, D1CBB3, D0DBDF, A9A199, BDB0A3, 7A7A85, B0A18E, or B0A18E.