Development of synthetic Brassica napus lines for the analysis of "fixed heterosis" in allopolyploid plants
Development of synthetic Brassica napus lines for the analysis of "fixed heterosis" in allopolyploid plants
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DOI：
10.1007/s10681-005-3364-7
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发表时间：
2005-11-01
期刊：
影响因子：
1.9
通讯作者：
Becker, HC
中科院分区：
文献类型：
--
作者：
Abel, S;Möllers, C;Becker, HC
异源多倍体广泛存在于植物界。它们的成功可能是由于不同基因组上的同源基因之间的正互作，类似于同一基因的不同等位基因之间的正互作导致杂合二倍体基因型的杂种优势。在异源多倍体中，这种相互作用也可以发生在纯合的基因类型中，因此可以称为“固定杂种优势”。据我们所知，没有实验数据支持这一假设。我们提出了一种量化人工合成甘蓝型油菜“固定杂种优势”的实验方法，并通过比较QTL定位甘蓝型油菜及其亲本甘蓝型油菜和甘蓝型油菜的“固定杂种优势”。为了获得遗传平衡材料，用21个甘蓝型油菜与16个甘蓝双单倍体或自交系进行种间杂交。总共从9514个授粉花蕾中获得了3485个活体胚胎。种间杂交的成功与否高度依赖于母本基因型(白菜型油菜)，每个授粉花蕾的胚数在0~1.18个之间。利用273个随机扩增多态DNA标记构建了甘蓝型油菜和甘蓝型油菜品系的遗传特征树。因此，现在有了一种特征良好的材料，它适合于分析“固定杂种优势”的影响和异源多倍体物种中同源基因之间的相互作用。
Allopolyploids are widely spread in the plant kingdom. Their success might be explained by positive interactions between homoeologous genes on their different genomes, similar to the positive interactions between different alleles of one gene causing heterosis in heterozygous diploid genotypes. In allopolyploids, such interactions can also occur in homozygous genotypes, and may therefore be called "fixed heterosis". As to our knowledge, no experimental data are available to support this hypothesis. We propose an experimental approach to quantify "fixed heterosis" in resynthesised Brassica napus and the detection of loci contributing to "fixed heterosis" via comparative QTL mapping in B. napus and its parental species B. rapa and B. oleracea. In order to develop a genetically balanced material, interspecific crosses between 21 Brassica rapa and 16 Brassica oleracea doubled haploid or inbred lines were performed. In total 3485 vital embryos have been obtained from 9514 pollinated buds. The success of interspecific hybridisation was highly depending on the maternal genotype (B. rapa) and ranged from 0 to 1.18 embryos per pollinated bud. For the genetic characterisation of the B. rapa and B. oleracea lines, a dendrogram was constructed based on 273 RAPD markers. Thus a well-characterised material is now available, which is suitable to analyse the effects of "fixed heterosis" and the interactions between homoeologous genes in allopolyploid species.