genetic variation associated with retrotransposon activation, genomic rearrangements and trait variation in a recombinant inbred line population of
Interspecific hybridization is a significant evolutionary force as well as a powerful method for crop breeding. Partial substitution of the AA subgenome in Brassica napus (AnAnCnCn) with the Brassica rapa (ArAr) genome by two rounds of interspecific hybridization resulted in a new introgressed type of B. napus (ArArCnCn). In this study, we construct a population of recombinant inbred lines of the new introgressed type of B. napus. Microsatellite, intron‐based and retrotransposon markers were used to characterize this experimental population with genetic mapping, genetic map comparison and specific marker cloning analysis. Yield‐related traits were also recorded for identification of quantitative trait loci (QTLs). A remarkable range of novel genomic alterations was observed in the population, including simple sequence repeat (SSR) mutations, chromosomal rearrangements and retrotransposon activations. Most of these changes occurred immediately after interspecific hybridization, in the early stages of genome stabilization and derivation of experimental lines. These novel genomic alterations affected yield‐related traits in the introgressed B. napus to an even greater extent than the alleles alone that were introgressed from the Ar subgenome of B. rapa, suggesting that genomic changes induced by interspecific hybridization are highly significant in both genome evolution and crop improvement.
Document Type: Research Article
Affiliations: 1: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China 2: Division of Biological Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA 3: Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea 4: Molecular Genetics and Genomics Lab, Department of Horticulture, Chungnam National University, Daejeon 305-764, Korea 5: Brassica Genomics Team, National Institute of Agricultural Biotechnology, Rural Development Administration, Suwon 441-707, Korea
Publication date: October 1, 2011