QTL analysis of essential oil, seed shattering, thousand-grain weight and stalk attachment rate in Carum carvi

Caraway (Carum carvi L.) is a medicinal and aromatic plant in the Apiaceae family, appreciated for its essential oil containing the main terpenoids carvone and limonene. While the essential oil content is crucial for quality, low seed shattering and high thousand-grain weight (TGW) are critical factors influencing seed yield. Molecular breeding tools are limited in Apiaceae, except for carrot, leading to a QTL mapping study of these seed-related traits in two F2 populations (E(N(P1) = 236; N(P2) = 266)).

In population P1, with non-shattering maternal parent Rekord, at least one shattering locus on LG03 (9.9% PVE) was identified. Moreover, loci linked to essential oil (LG08, 10.5% PVE) and TGW (LG09, 11.1% PVE) were detected. In population P2, six essential-oil loci (LG02-06, LG10; combined PVE: 49.2%) were found, including five affecting both carvone and limonene and one exclusive to limonene.

Additionally, a major QTL for TGW was mapped to LG02 (15.6% PVE). For stalk attachment rate, one minor QTL was detected on LG07 (8.5% PVE), with no QTL co-localized with the primary shattering locus.

The researchers developed and validated 26 diagnostic PACE markers to cover five key QTLs, aiming to facilitate fine-mapping efforts in Carum carvi breeding.