A STRATEGY FOR GENETIC MAPPING OF POLYPLOID KIWIFRUIT (ACTINIDIA) SPECIES
Most of the kiwifruit produced worldwide are from A. chinensis var. deliciosa (6x). A genetic map of diploid A. chinensis var. chinensis has been constructed using microsatellite markers, and mapping of hexaploid A. chinensis var. deliciosa would assist in developing new cultivars. However, mapping in polyploids introduces the problem of determining allele dosage. We have hypothesized that one way of solving this problem would be to genetically map using progeny from an interspecific cross between hexaploid A. chinensis var. deliciosa and diploid A. eriantha. Parents and progeny were genotyped for microsatellite markers that mapped to linkage group 2 (LG2) in diploid A. chinensis var. chinensis. The dosages of alleles in the A. chinensis var. deliciosa parent were estimated from the proportion of progeny that exhibited the allele, and the alleles that appeared to be present as a single copy in the A. chinensis var. deliciosa parent were mapped. Each different-sized A. chinensis var. deliciosa allele was scored as a separate marker, giving up to six markers per microsatellite. A. eriantha alleles were excluded. When markers were grouped in JoinMap 3.0, six groups for LG2 were created, depending on the alleles that were present before alleles were ordered, based on their recombination. This allowed mapping of each of the six homologs of LG2 in Actinidia chinensis var. deliciosa. Results suggest that there is considerable conservation of gene order of LG2 between A. chinensis var. deliciosa and A. chinensis var. chinensis. We conclude that our tetraploid progeny approach would successfully develop a genetic linkage map of hexaploid A. chinensis var. deliciosa with sufficient marker density and a large mapping population.
Datson, P.M., Mertton, D., Tsang, G.K., Manako, K.I., Fraser, L.G. and McNeilage, M.A. (2013). A STRATEGY FOR GENETIC MAPPING OF POLYPLOID KIWIFRUIT (ACTINIDIA) SPECIES. Acta Hortic. 976, 449-453
Actinidia chinensis var. deliciosa, polyploidy, Actinidia eriantha