Inheritance and InDel markers closely linked to petal color gene (cpc-1) in Brassica oleracea

Abstract

Brassica oleracea contains several subspecies, including cabbage, broccoli, cauliflower, Chinese kale and kohlrabi. The petals of B. oleracea are either yellow or white. Cabbages usually have yellow petals, while Chinese kale mostly has white petals. However, the molecular mechanism of petal color formation in B. oleracea is unknown. In this study, F2 and BC1P1 (backcross) populations were constructed from a cross between the cabbage inbred line YL-1 (P1) and the Chinese kale inbred line 11-192 (P2). Analysis of the inheritance of petal color indicated that white petal color was controlled by a single dominant gene, termed cpc-1. Insertion–deletion (InDel) markers were designed based on B. oleracea reference genome sequence and re-sequencing data of the parents. Subsequently, bulked segregation analysis was used to detect polymorphisms of the InDels. A genetic map constructed with 10 InDels indicated that cpc-1 was located on chromosome C03. The cpc-1 gene is flanked by InDels M4136 and M4139, with genetic distances of 0.4 and 0.9 cM, respectively. The interval distance between the two markers is 503 kb. This study lays the foundation for cloning cpc-1 and revealing the molecular mechanism of petal color formation in B. oleracea.