Authors: Anja Bus Niklas Körber Rod J Snowdon Benjamin Stich
Publish Date: 2011/08/17
Volume: 123, Issue: 8, Pages: 1413-1423
Abstract
Rapeseed Brassica napus L is the leading European oilseed crop serving as source for edible oil and renewable energy The objectives of our study were to i examine the population structure of a large and diverse set of B napus inbred lines ii investigate patterns of genetic diversity within and among different germplasm types iii compare the two genomes of B napus with regard to genetic diversity and iv assess the extent of linkage disequilibrium LD between simple sequence repeat SSR markers Our study was based on 509 B napus inbred lines genotyped with 89 genomespecific SSR primer combinations Both a principal coordinate analysis and software STRUCTURE revealed that winter types spring types and swedes were assigned to three major clusters The genetic diversity of winter oilseed rape was lower than the diversity found in other germplasm types Within winter oilseed rape types a decay of genetic diversity with more recent release dates and reduced levels of erucic acid and glucosinolates was observed The percentage of linked SSR loci pairs in significant r 2 Q 95 unlinked loci pairs LD was 629 for the entire germplasm set Furthermore LD decayed rapidly with distance which will allow a relatively high mapping resolution in genomewide association studies using our germplasm set but on the other hand will require a high number of markersThe authors thank Wolfgang Ecke University of Göttingen Germany the Leibniz Institute of Plant Genetics and Crop Plant Research Gatersleben Germany Nordic Gene Bank Alnarp Sweden The Centre for Genetic Resources Netherlands and Warwick Horticulture Research International Genetic Resources Unit UK for providing the seeds of the examined germplasm Agriculture and AgriFood Canada kindly shared the proprietary Brassica SSR markers and their map positions We are grateful to Sarah Nele Kaul and Bent Müller for the technical assistance as well as to the Max Planck Genome Centre Cologne for providing the genotyping facilities The funding of this work is kindly provided by the Deutsche Forschungsgemeinschaft DFG and the Max Planck Society This work was performed in the framework of the ERANET PG project “ASSYST” Finally we thank the associate editor C Quiros and three anonymous reviewers for their valuable suggestions
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