Fig. 2

Mapping of the Rfn gene on chromosome A09. a Flowers from the parents and BC1 progeny of the mapping cross. Petals have been removed to allow display of anther morphology. Cytoplasm is designated in parentheses. The male parent of the cross and fertile progeny heterozygous for Rfn (Rfn/rf) have anthers with normal morphology and shed abundant pollen. The male sterile (CMS) parent and BC1 progeny homozygous for the recessive maintainer allele (rf/rf) have stamens with short filaments and underdeveloped anthers that shed little or no pollen. b Location of Rfn on chromosome A09. The region of the B. rapa chromosome chosen as range for targeted mapping extending from coordinates 39.5 to 43.5 Mb is expanded to illustrate the mapping results. Numbers in parentheses indicate the number observed recombination events between a marker at that location and the Rfn gene. The filled rectangle indicates position of the BAC spanning the region delimited in Rfp mapping experiments. No recombination was observed between the single marker located within the BAC and the Rfn gene