Resistant carrots to Alternaria dauci or tasty carrots: should we choose?

The carrot ideotype for carrot breeders could be a variety resistant to Alternaria leaf blight – the main foliar disease on carrot worldwide – with a low level of bitterness as consumers consider it as an undesirable taste of carrots.
Our previous investigation on carrot resistance to Alternaria dauci allowed the identification of resistance QTLs (rQTLs). Based on these results, breeding for a higher level of resistance is possible but we could interrogate about the impact of selecting these genomic regions on carrot bitterness.
To answer this question, we combined chemical and sensorial analyses of a set of resistant and susceptible carrot genotypes evaluated in different environments to identify the metabolites involved in bitterness.
The genetic control and heritability in field experimentation and colocalizations between rQTLs and metabolite QTLs (mQTLs) were searched in order to evaluate the link between bitterness and resistance traits.
Our results showed that selecting the genomic regions mainly involved in carrot resistance is possible without compromising carrot taste.
However, the colocalization of rQTLs and mQTLs suggest that some genomic regions are involved in the expression of both traits and should be avoided or even counter selected.

II International Symposium on Carrot and Other Apiaceae

V. Le Clerc, C. Aubert, V. Cottet, C. Yovanopoulos, M. Piquet, A. Suel, S. Huet, C. Koutouan, L. Hamama, G. Chalot, M. Jost, B. Pumo, M. Briard

root quality, bitterness, metabolite QTL, leaf blight, Daucus carota

https://doi.org/10.17660/ActaHortic.2019.1264.24