4. Sectorial sun red (Genetics 24:108) induced by ultraviolet pollen treatment, is changed to sectorial purple when crossed by dilute purple A b Pl. Also sectorial sun red shows a linkage (F₂ data) with gl2 and v4. C.O. percent gl2 and sectorial sun red = 19; between v4 and sectorial sun red = 32%. These values approximate the crossover values with B, 19 and 21 percents respectively. This is evidence the recessive sun red represents a change from the original B factor that was treated and is not another independent factor acting upon the B gene. This character is being studied further.