Department of Vegetable Crops, University of California, 95616, Davis, CA, USA.
Theor Appl Genet. 1987 Oct;74(6):758-66. doi: 10.1007/BF00247554.
This study aimed at generating chromosome addition lines and disclosing genome specific markers in Brassica. These stocks will be used to study genome evolution in Brassica oleracea L., B. campestris L. and the derived amphidiploid species B. napus L. B. campestris-oleracea monosomic and disomic chromosome addition plants were generated by crossing and backcrossing the natural amphidiploid B. napus to the diploid parental species B. campestris. The pollen viability of the derived sesquidiploid and hyperploid ranged from 63% to 88%, while the monosomic and disomic addition plants had an average pollen fertility of 94% and 91%, respectively. The addition lines were genetically characterized by genome specific markers. The isozymes for 6PGD, LAP, PGI and PGM, and rDNA Eco RI restriction fragments were found to possess the desired genome specificity. Duplicated loci for several of these markers were observed in B. campestris and B. oleracea, supporting the hypothesis that these diploid species are actually secondary polyploids. A total of eight monosomic and eight disomic addition plants were identified and characterized on the basis of these markers. Another 51 plants remained uncharacterized due to the lack of additional markers. rDNA genes were found to be distributed in more than one chromosome, differing in its restriction sites. Intergenomic recombination for some of the markers was detected at frequencies between 6% and 20%, revealing the feasibility of intergenomic gene transfer.
本研究旨在生成甘蓝型油菜、白菜和其衍生的双二倍体物种的染色体添加系，并揭示基因组特异标记。这些品系将被用于研究甘蓝型油菜、白菜的基因组进化。通过将天然双二倍体甘蓝型油菜与二倍体亲本白菜杂交和回交，产生了白菜-甘蓝型油菜的单体和二体异附加系。衍生的半二倍体和超二倍体的花粉活力为 63%至 88%，而单体和二体异附加系的花粉育性分别为 94%和 91%。利用基因组特异标记对添加系进行了遗传特征分析。发现 6PGD、LAP、PGI 和 PGM 的同工酶以及 rDNA Eco RI 限制片段具有所需的基因组特异性。在白菜和甘蓝型油菜中观察到这些标记的多个重复位点，支持了这些二倍体物种实际上是次生多倍体的假说。基于这些标记，共鉴定和表征了 8 个单体和 8 个二体异附加系。由于缺乏附加标记，还有 51 个品系无法进行特征描述。rDNA 基因被发现分布在不止一条染色体上，其限制位点不同。一些标记的种间重组频率在 6%至 20%之间，表明种间基因转移是可行的。
