Studies On Genetic Diversity And Relationship Of Brassica Oleracea L. Using AFLP Markers

The Brassica genus comprises a large and diverse group of plant species and Brassica oleracea. is one of the most important crops in China. To reveal their phylogenetic relationships and genetic diversity, 283 Brassica oleracea. Accessions, representing the five main varieties of the genus Brassica oleracea L, were analyzed with AFLP markers and morphological characteristics.Using 9 primer pairs, 689 informative AFLP markers were generated and scored as binary data, which showed a polymorphic band ratio of 66.9%. The fingerprinting data were further analyzed using Hierarchical Cluster methods in the software package SPSS, which clustered the 283 accessions into five main distinct groups, presenting cauliflower, broccoli, Chinese kale, kohlrabi and cabbage. The average genetic similarity within each group was 0.808, 0.75, 0.739, 0.742 and 0.7 for cauliflower, broccoli, Chinese kale, kohlrabi and cabbage respectively. The highest genetic similarity among the groups is 0.69 found between cauliflower and broccoli, while the lowest is 0.578 found between cabbage and kohlrabi.The relationships within cabbage and broccoli inbred lines were also assessed using AFLP techniques. Four subgroups presenting spring cabbage, red cabbage, autumn cabbage and the cabbage come from Taiwan can be obviously distinguished by AFLP technique. The average genetic similarity within spring cabbage is 0.808, the highest one within the 4 subgroups, suggests a limited genetic variation within this subgroup. Spring cabbage and red cabbage have the most closely relationship in our study. Red cabbage has almost the same genetic distance to spring cabbage and autumn cabbage.Different from the traditional classification, our results indicated that brussel sprouts and red cabbage were two subgroups of the cabbage group. This result should be further verified.