Single Locus, Multiallelic Inheritance of Erucic Acid Content and Linkage Mapping of FAE1 Gene in Yellow Mustard

With our objective to develop inbred lines as synthetic components in yellow mustard (Sinapis alba L.), we have isolated different erucic acid variants. The genetic basis of variation in erucic content was investigated using the four variants Y517, Y496, Y1130, and Y514 with high (approximately 50%), medium (approximately 24%), low (approximately 1.4%), and zero (<0.1%) erucic contents, respectively. The segregation of this trait in the BC1F1 and F-2 populations of the two crosses Y514 x Y496 and Y514 x Y517 indicated that it was under monogenic control with partial dominance for the high content. To test the allelism of the genes for high, medium, and low erucic contents, crosses were made among Y517, Y496, and Y1130, respectively. The erucic content was also controlled by one gene and no transgressive segregant of zero erucic phenotype was observed in the resulting F-2 populations. Therefore, it was concluded that the genes for high, medium, low, and zero erucic contents were different alleles of the same locus. Accordingly, we designated the erucic alleles in Y517, Y496, Y1130, and Y514, as "E-1," "E-2," "E-3," and "e," respectively. The regional linkage maps of the high erucic gene FAE1.E-1 and the medium erucic gene FAE1.E-2 were constructed using intron length polymorphism markers. The two genes FAE1.E-1 and FAE1.E-2 were mapped to the same chromosomal position, further confirming the single locus, multiallelic control of erucic content in yellow mustard.