High-resolution linkage mapping of the vernalization requirement gene ‘Vrn1’ in carrot (Daucus carota L.)
Josefina Wohlfeiler Altavilla
University of Wisconsin-Madison
Carrots are typically classified as annual or biennial, depending on their vernalization requirement for flowering, a trait that is genetically-conditioned. Wild carrots are predominantly annual, requiring less hours of cold temperatures for flower induction, whereas most cultivated carrots are biennial (i.e., they have higher cold temperature requirements). After vernalization, if followed by long days, floral stem elongation and flowering take place. Previous studies using F2 and BC1 families derived from crosses between an early and a late flowering line revealed segregation ratios consistent with a monogenic character with annual habit being dominant over biennial; and this gene -called Vrn1- was later mapped to chromosome 2 exhibiting tightly linked (0.70 and 0.46 cM) flanking markers. In order to further resolve the map region of Vrn1, we will develop SNPs markers in the Vrn1 region, which will be used in a large segregating population (~ 1100 F2 individuals). The objective of the project is the construction of a high resolution linkage map in the Vrn1 region that allows further analysis of candidate genes for the genetic control of the vernalization requirement in carrot. SNPs markers will be genotyped in the F2 population using GBS technology, and the map will be constructed using JoinMap 4.0 software. The collaboration with Dr. Simon´s lab at the University of Wisconsin will be a great contribution to this project.