Carotenoid Content and Root Color of Cultivated Carrot: A Candidate-Gene Association Study Using an Original Broad Unstructured Population

Article de revue (Article scientifique dans une revue à comité de lecture)International audienceAccumulated in large amounts in carrot, carotenoids are an important product qualityattribute and therefore a major breeding trait. However, the knowledge of carotenoid accumulationgenetic control in this root vegetable is still limited. In order to identify the geneticvariants linked to this character, we performed an association mapping study with a candidategene approach.We developed an original unstructured population with a broad geneticbasis to avoid the pitfall of false positive detection due to population stratification. Wegenotyped 109 SNPs located in 17 candidate genes – mostly carotenoid biosynthesisgenes – on 380 individuals, and tested the association with carotenoid contents and colorcomponents. Total carotenoids and β-carotene contents were significantly associated withgenes zeaxanthin epoxydase (ZEP), phytoene desaturase (PDS) and carotenoid isomerase(CRTISO) while α-carotene was associated with CRTISO and plastid terminal oxidase(PTOX) genes. Color components were associated most significantly with ZEP. Our resultssuggest the involvement of the couple PDS/PTOX and ZEP in carotenoid accumulation, asthe result of the metabolic and catabolic activities respectively. This study brings new insightsin the understanding of the carotenoid pathway in non-photosynthetic organs.