Efficacy and Cost Evaluation Using R1-nj Phenotype to Select Haploid Sweet Corn
Double haploid methodology has become a popular practice in many maize breeding programs because of the reduction in breeding generations and materials used to create inbred lines. To create haploid lines, an inducer that contains a phenotypic marker is used to cross with the F1 donor population. There are two main genetic loci that influence these phenotypic markers, R1-nj and Pl1. R1-nj causes distinction between a pigmented embryo and aleurone layer compared to a non-pigmented embryo and aleurone layer. Pl1 causes strong pigmentation of the roots and coleoptile in juvenile and adult plants.
In corn, it is difficult to use R1-nj for selection, because of the difficulty to view the pigmentation in the embryo and lack of pigmentation in the aleurone layer. The purpose of this study was to determine how efficient the pre-selection screening process is when using R1-nj to select potential haploids in sweet corn.