IDENTIFICATION AND MAPPING OF 3 FLOWER COLOR LOCI OF POTATO (SOLANUM-TUBEROSUM L) BY RFLP ANALYSIS

The inheritance of flower colour in diploid potato (2 n = 2 x = 24), w as found to be controlled by three unlinked loci D, F and P. To determ ine the allelism with previously described loci and to dissect this ol igogenic trait, a set of tester clones with well-defined genotypes was developed. By backcrossing the mapping population with these tester c lones it was possible to obtain monogenic segregation ratios. These we re required to detect linkage with RFLP loci and, despite distorted Me ndelian ratios, the inheritance and mapping of the D, F and P loci cou ld be unambiguously determined. Locus D, involved in the biosynthesis of red anthocyanins, was mapped on chromosome 2, while locus P, involv ed in the production of blue anthocyanins, was mapped on chromosome 11 . Locus F, involved in the flower-specific expression of gene(s) accom modated by the D and P loci, was mapped on chromosome 10. The tester c lones and the map position of the D, F and P loci may be of considerab le value in simplifying the genetics of anthocyanin pigmentation.