Technique for rapid, small-scale analysis of vitamin C levels in fruit and application to a tomato mutant collection.

We present a technique for easy, rapid analysis of both total and reduced forms of vitamin C in fruits using microplates and a plate reader. This technique has been compared with a spectrofluorometric technique classically used for assaying vitamin C in fresh tomato. We have applied these methods to a population of 118 tomato mutant lines and controls in search of variability for this trait. Six lines, identified as having high vitamin C levels, and four lines having low vitamin C levels have been chosen for further study. The vitamin C levels have been compared with sugar concentration, dry matter content, fruit weight, titratable acidity, and firmness. The correlations that often exist in tomato varieties between sugar and vitamin C content (positive correlation) or fruit weight and vitamin C content (negative correlation) can be uncoupled in the lines selected for further analysis.