The application of genome selection to kiwifruit breeding
One of the difficulties in breeding for fruit traits in dioecious plants such as kiwifruit is the selection of male parents. Currently the breeding values of potential male parents for fruit traits are estimated by progeny tests, which are both expensive and time consuming. A potential major advantage of applying genome selection (GS) to kiwifruit is that GS does not rely exclusively on progeny information, and this will allow the direct selection of sex-limited traits. The availability of a genome sequence of a diploid Actinidia chinensis is a major step forward for the application of GS in kiwifruit, but there are still significant hurdles that need to be overcome. The current sequence assembly could be improved; kiwifruit are highly heterozygous; and most breeding populations are polyploid. We report on the application of restriction enzyme-based genotyping-by-sequencing (GBS) in diploid A. chinensis to obtain genotype information for an initial application of GS to 86 individuals from a diploid A. chinensis training population. Two plants were used as controls for the repeatability of GBS, a pair of libraries were produced and sequenced from each of these and only a low level of consensus was discovered 89.3% for the first pair and 78.1% for the second. The correlations between genome estimated breeding values (GEBVs) were greater than 0.5 for seven out of the 11 traits tested, suggesting that the application of GS will be useful for kiwifruit breeding but improvement in the genotyping approach is needed.
Datson, P.M., Barron, L., Manako, K.I., Deng, C.H., De Silva, N., Bomert, M., Cheng, C.H., Crowhurst, R. and Hilario, E. (2017). The application of genome selection to kiwifruit breeding. Acta Hortic. 1172, 273-278
GS, genotyping-by-sequencing, GBS, Actinidia