36th International Carrot Conference Abstract

Diversity in carrot: variation in a structured collection of genetic resources

C. J. Allender and M. de Cesare

Warwick Crop Centre, University of Warwick, Wellesbourne Campus, Warwick, CV35 9EF, UK

The Vegetable Genetic Improvement Project aimed to develop a pre-breeding resource for the carrot breeding and research community. The Carrot Diversity Set is based on 77 accessions sourced from Warwick Genetic Resources Unit, focusing mainly on the global cultivated carrot genepool but also including closely related wild taxa. Parental lines from genetic mapping populations are also included. Variation in traits such as seed size, seed and seedling vigour and flowering time were assessed, and two classes of molecular markers (DArT markers and chloroplast microsatellites) were used to understand the pattern and partitioning of genetic variation present. The results indicate that the Carrot Diversity Set has captured a broad range of variation from the global cultivated genepool, and that the Asiatic section of the genepool is relatively rich in genetic diversity compared to European and American types. The maternally inherited chloroplast genome exhibited high levels of diversity, with twenty nine haplotypes being detected using seven polymorphic markers. Many of the haplotypes were not shared among accessions. Phenotypic variation was also extensive, with flowering behaviour ranging as expected from annual to biennial; the timing of flowering of accessions showing annual-type behaviour ranged from 7 weeks to 23 weeks after sowing. Germination time and rates of seedling growth as measured under laboratory conditions also varied across the set, and were not strongly correlated with seed size. The genetic and trait data available will enable the carrot diversity set to be a useful tool in understanding the genetic basis of traits of interest in carrots, and in transferring the results of research into breeding programmes through the development of further pre-breeding resources in the future.

Last updated Thursday, 25-Jul-2013 11:52:53 CDT