The ratio of the error resulting from a best-fit circle to the area of the seed. Error is the average magnitude of residuals (Res) along the seed's perimeter, divided by the radius of the circle. Smaller values indicate that the seed is more circular.
At least three inflorescences for each plant were bagged before anthesis and manually crossed to another individual from the same population of origin. Seeds were let to dry on the plant, collected, cleaned and store in an hermetically sealed box containing silica gel. Eigth seeds from each plant were imaged using a high resolution scanner, at a resolution of 2400 dpi. A size and colour standard was included in each picture. Images were analyed using Tomato Analyzer (Rodrigues. et al. 2010); object boundaries in Tomato Analyzer were manually adjusted to exclude seed hair.