Analysis of SlMYB12 gene polymorphism determining chalcone-naringenin biosynthesis in the skin of tomato fruits and its effect on the lycopene accumulation.

Abstract

Efficiency in detecting of tomato forms with no chalcone-naringenin flavonoid in pink-fruited and yellow-fruited forms was evaluated using DNA markers for various polymorphisms of the SlMYB12 gene. The closest relationship between a phenotype with the transparent skin of fruits and a deletion in the promoter region of the SlMYB12 gene was shown. The highest efficiency in the detection of the recessive y allele of the regulatory SlMYB12 gene, leading to the chalcone-naringenin synthesis disruption and skin transparency, was established by a combination of markers MYB12-603delaF1/603del-aR6 (Myb-603del aF1/R6) and MYB12-603del-aF1/603del-aR5 (Myb12 aF1/R5). Fruit coloration peculiarities were shown depending on a combination of the structural alleles of a carotenoid biosynthesis pathway and SlMYB12 gene alleles. A combination of this y allele with the alleles of the gene of the lycopene-β-cyclase beta (b) and old gold crimson (ogc ) allows selecting pink and raspberry forms respectively. In tomato accessions with yellow and orange fruits, the y allele provides pale shades of the main coloration determined by carotenoid biosynthesis genes (yellow flesh (r), tangerine (t), Beta (B)). The presence of SNP T → C of the SlMYB12 gene (171476848 position of chromosome 1) was identified in 80 % of accessions with the transparent skin of fruits of the evaluated collection. The effect of the recessive y allele of the SlMYB12 gene on an increase in the lycopene concentration of tomato fruits in a combination with b, ogc alleles was shown. Using MAC methods by fruit quality genes, including the SlMYB12 gene, the cherry tomato variety Malinovyj koktel with a high lycopene accumulation was developed and included in the State Register