Two tomato lines with normal maturation (NR-1 and NR-2) have been crossed with two mutant lines (NR-10 nor and NR-12 rin) with delayed maturation (shelf life). Determination of mutant genes has been done by χ2 test on 100 fruits from F2 generation. Fruits have been picked 65 days from antesis and kept for 60 days, when six evaluations have been done. Data have been collected every 10 days on parental lines and progeny F1 and F2 generation. Variance testing has been done on the basis of one- and two-factorial analysis and groups compared by contrasts. Fruits have been preserved in controlled conditions (in dark at 5°C). Tomato genotypes with nor or rin gene had desirable traits (delayed ripening, long shelf life and firm fruits) for modern selection, so they should be included in programmes aiming to create commercial F1 hybrids.