Effect of mutant genes on the content of the nutritive quality related compounds in tomato (Solanum lycopersicum) fruits

The effects of three pigment enhancing mutant genes, high pigment (hp), old gold crimson (og(c)) and Anthocyanin fruit (Aft) on fruit and fruit quality characters of tomato were investigated. Three isogenic lines in Alisa Craig background with hp/hp, og(c)/og(c), Aft/Aft genes were employed in this study. Mutant hybrids were developed by crossing among the three isogenic lines of Alisa Craig having the mutant genes. Mutant x non-mutant hybrids were developed by crossing the three isogenic lines of Alisa Craig with three non-mutant and normal breeding lines 3 x 3 line x tester mating design. The hybrids along with the respective parental lines were evaluated for different fruit and fruit quality characters. The og(c)/og(c) genotype caused favourable expression of all the fruit characters while hp/hp gene had depressive effect and fruit characters of the Aft/Aft genotype had moderate expression. The og(c)/og(c) genotype caused highest enhancement of both lycopene and β carotene content in the fruits followed by the genotype with hp/hp and Aft/Aft gene. The genotype with the mutant gene Aft in both homo and heterozygous condition (Aft/Aft and Aft/Aft+) induced the high expression of anthocyanin pigment in fruit pericarp. The hp/hp and og(c)/og(c) gene also caused enhancement of anthocyanin content in the fruits compared to the non-mutant lines. Simultaneous presence of og(c)/og(c+) Aft/Aft+ gene in the genotype markedly increased lycopene, β carotene and anthocyanin contents of the fruits. The high pigment and old gold crimson gene in heterozygous condition (hp/hp+ and og(c)/og(c+)) also enhanced lycopene and β carotene content in the fruits although the enhancement was much more pronounced in the homozygous condition of these two mutant genes. The mutant hybrid og(c)/og(c+) Aft/Aft+ emerged as outstanding and two mutant x non-mutant hybrids Alisa Craig og(c) x Patharkutchi and Alisa Craig og(c) x BCT 53 (og(c)/og(c)+) was also promising. The old gold crimson (og(c)) and anthocyanin fruit (Aft) mutant could effectively be employed in breeding tomato hybrids with improved fruit quality.