Molecular characterization of berry color locus on the portuguese cv. ‘Fernão Pires’ and cv. ‘Verdelho’ and their red-berried somatic variant cultivars

Abstract

Genotyping studies are increasing the knowledge on grapevine biodiversity, particularly regarding grape berry skin color somatic variants, supporting the research on the color trait. This study aimed to evaluate the effect of the berry color locus, and its surrounding genomic region, on the color variation of the Portuguese white-skinned cultivars ‘Fernao Pires’ and ‘Verdelho’ and its derived red-berried somatic variants cv. ‘Fernao Pires Rosado’ and cv. ‘Verdelho Roxo’, respectively.The analysis of Gret1 insertion within the VvMYBA1 gene revealed no polymorphism responsible for white-to-red shift of the red-skinned cv. ‘Fernao Pires Rosado’ and cv. ‘Verdelho Roxo’. Moreover, VvMYBA2 showed an important role regarding the phenotypic variation of cv. ‘Fernao Pires’, through the recovery of the functional allele G on cv. ‘Fernao Pires Rosado’. Regarding the data obtained for cv. ‘Verdelho’ and cv. ‘Verdelho Roxo’, both cultivars showed Gret1 insertion on VvMYBA1 and non-functional T allele on VvMYBA2 in homozygosity for both cell layers of shoot apical meristem, suggesting the occurrence of other mutational events responsible for the color gain.