Parental polymorphism analysis in marker assisted selection for β-carotene rich maize

Abstract

Marker assisted selection (MAS) is widely implemented into modern grain breeding programs. Molecular markers are used in foreground selection to control the target gene, as well as in background selection to accelerate the reconstruction of the recurrent parent genotype. The best results have been achieved with the qualitative traits, regulated by the action of a single or several genes and clearly phenotypically defined. One successful example of MAS is the improvement of β-carotene content using crtRB1 specific molecular marker. Maize Research Institute "Zemun Polje" has a breeding program aimed at conversion of standard maize to β-carotene rich genotypes adapted to temperate regions. The objectives of this study were to test the utility of gene-specific SSR marker in foreground selection and to identify polymorphic markers between parental lines to be used in background selection. Genetic variability between two standard and three high β-carotene parental inbred lines was analyzed with 40 SSRs distributed over the maize genom. Total number of alleles detected with 30 informative markers was 77, average being 2.57. The genetic similarity values calculated on Dice coefficient ranged from 0.49 to 0.66. Parental polymorphism for crtRB1 showed a 543 bp fragment in donor lines, whereas a distinct 296 bp amplicon and a faint 1221 bp amplicon were generated in the recurrent parents. This marker will be used as foreground selection marker for the crtRB1 gene in the conversion of standard maize to β-carotene enriched lines for growing in temperate regions.