The flower petals of B.napus are usually yellow,but very occasionally white in some re-synthesized lines.No.2127 was a re-synthesized double haploid line with white flowers derived from the cross between B.rapa var.Yellow Sarson with yellow petals,and B.oleracea var.alboglabra with white petals.The inheritance of flower color in an F2 population derived from the cross between No.2127 and Zhongyou 821 (ZY821) indicated the white color is dominant over the yellow color and controlled by a single gene.