Qian W, Meng J, Li M, Frauen M, Sass O, Noack J, Jung C
National Key Laboratory of Crop Genetic Improvement and National Center of Crop Molecular Breeding, Huazhong Agricultural University, Wuhan, 430070, China.
Theor Appl Genet. 2006 Jun;113(1):49-54. doi: 10.1007/s00122-006-0269-3. Epub 2006 Apr 8.
In spite of its short history of being an oil crop in China, the Chinese semi-winter rapeseed (Brassica napus L., 2n = 38, AACC) has been improved rapidly by intentional introgression of genomic components from Chinese B. rapa (2n = 20, AA). As a result, the Chinese semi-winter rapeseed has diversified genetically from the spring and winter rapeseed grown in the other regions such as Europe and North America. The objectives of this study were to investigate the roles of the introgression of the genomic components from the Chinese B. rapa in widening the genetic diversity of rapeseed and to verify the role of this introgression in the evolution of the Chinese rapeseed. Ten lines of the new type of rapeseed, which were produced by introgression of Chinese B. rapa to Chinese normal rapeseed, were compared for genetic diversity using amplified fragment length polymorphism (AFLP) with three groups of 35 lines of the normal rapeseed, including 9 semi-winter rapeseed lines from China, 9 winter rapeseed lines from Europe and 17 spring rapeseed lines from Northern Europe, Canada and Australia. Analysis of 799 polymorphic fragments revealed that within the groups, the new type rapeseed had the highest genetic diversity, followed by the semi-winter normal rapeseed from China. Spring and winter rapeseed had the lowest genetic diversity. Among the groups, the new type rapeseed group had the largest average genetic distance to the other three groups. Principal component analysis and cluster analysis, however, could not separate the new type rapeseed group from Chinese normal rapeseed group. Our data suggested that the introgression of Chinese B. rapa could significantly diversify the genetic basis of the rapeseed and play an important role in the evolution of Chinese rapeseed. The use of new genetic variation for the exploitation of heterosis in Brassica hybrid breeding is discussed.
尽管中国冬油菜作为一种油料作物的历史较短，但通过有意导入中国白菜型油菜（2n = 20，AA）的基因组成分，中国半冬性油菜（甘蓝型油菜，2n = 38，AACC）已得到快速改良。结果，中国半冬性油菜在遗传上与欧洲和北美等其他地区种植的春油菜和冬油菜有所不同。本研究的目的是调查导入中国白菜型油菜基因组成分在拓宽油菜遗传多样性方面的作用，并验证这种导入在中国油菜进化中的作用。利用扩增片段长度多态性（AFLP）技术，将通过将中国白菜型油菜导入中国常规油菜而培育出的10个新型油菜品系与三组共35个常规油菜品系进行遗传多样性比较，这三组常规油菜包括9个来自中国的半冬性油菜品系、9个来自欧洲的冬油菜品系以及17个来自北欧、加拿大和澳大利亚的春油菜品系。对799个多态性片段的分析表明，在各群体内部，新型油菜的遗传多样性最高，其次是来自中国的半冬性常规油菜。春油菜和冬油菜的遗传多样性最低。在各群体之间，新型油菜群体与其他三个群体的平均遗传距离最大。然而，主成分分析和聚类分析无法将新型油菜群体与中国常规油菜群体区分开来。我们的数据表明，导入中国白菜型油菜可显著拓宽油菜的遗传基础，并在中国油菜的进化中发挥重要作用。本文还讨论了利用新的遗传变异来开发甘蓝型油菜杂种优势的问题。
