Journal
EUPHYTICA
Volume 146, Issue 1-2, Pages 157-163Publisher
SPRINGER
DOI: 10.1007/s10681-005-3364-7
Keywords
allopolyploids; Brassica; epistasis; fixed heterosis; interspecific hybridisation; QTL mapping
Categories
Ask authors/readers for more resources
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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available