油菜屬十字花科(Brassicaceae)芸薹屬(Brassica)植物，有六個重要種，其中包含異源四倍體(allotetraploid) 或雙二倍體(amphidiploid)以及雙倍體(diploid)，這六個種可分成三種不同基因組(genome)，A genome、B genome 和C genome (n = 10, 8, and 9)。油菜近緣種之間會產生種間雜交，為了解大油菜(Brassica napus) 與小油菜(B. rapa)雜交後的子代變化及如何區分雜交後代，本研究選擇了四種B. napus 品種，搭配臺灣常見的B. rapa 品種，在溫室種植並進行兩者間的人工雜交，先取得雜交後代種子，再進行有關外表型及基因型上的分析。在外表型上的分析結果顯示，雜交後代與親代間的差異性並不明顯，不足以作為辨別的根據，因此進行基因型分析。首先利用流式細胞儀分析雜交後代，結果證實細胞內核酸含量介於兩親之間。在分子標誌部分選擇了SRAP (sequence-related amplified polymorphism)為應用之技術，在所使用的7 組SRAP 引子組合中，除引子組合5-6 沒有不同的條帶可供辨別外，其餘6 組引子組合共偵測出至少6 個以上的可辨別條帶以供親本及雜交後代辨別之用。 Brassica species, belonging to Brassica, is a genus of plants in the Brassicaceae family. Brassica plants have six important species, which can be divided into three different genome types, including A genome (n = 10), B genome (n = 8), and C genome (n = 9). Brassica species can hybridize between their relatives, called interspecific hybridization. In order to identify the difference among B. rapa, B. napus, and F1 hybrids, we employed four B. napus species and a B. rapa species which is green manure species grown in Taiwan. We planted all materials in the greenhouse and then implemented the crossing experiments to produce the hybrid seeds, followed by the analysis of their genotype and phenotype. At first, we used the flow cytometric (FCM) to analyze the parents and offsprings. It was found that the DNA content of hybrids was between their two parents. Then, we used 7 primer pairs from the thirty sequence-related amplified polymorphism (SRAP) primer pairs to analyze the hybrids. Except primer pairs 5-6, at least 6 polymorphic molecular markers were found in other 6 primer pairs. These markers could be used to identify all hybrids.