In 1976 several crosses were made to determine if any linkage existed between ms2 and selected genes from the Genetic Type Collection (Bernard and Weiss, 1973). The results from the F2 generation are presented in Table 1 with a= XV, b= xV, c= Xy and d= xy for the gene pairs listed in the form Xx and Vy. The ratio of products method (Irrmer and Henderson, 1943) was used to determine the percentage recombination
