Overlapping QTL associated with seed traits in a bi-parental population of Camelina sativa highlights a potential role for FLOWERING LOCUS C

The oilseed of camelina [ Camelina sativa (L.) Crantz] is a valued feedstock for sustainable aviation fuel and there is a need for germplasm with larger seeds, increased crude protein (CP), total fat (TF), and appropriate fatty acid (FA) profiles. Here, recombinant inbred lines (RILs) from a biparental (spring ’C046’ x winter ’Joelle’) cross were classified by days to flowering (DTF) and phenotyped for thousand seed weight (TSW), seed area (SA), CP, TF, and linoleic (18:2), linolenic (18:3), and eicosenoic (20:1) acids. Multivariate analysis produced a significant (p < 0.0001) correlation ( r = 0.9) between SA and TSW, and negative correlations between linoleic acid and other seed traits. A linkage map covering the 20 camelina chromosomes (Chr) identified quantitative trait loci (QTL) and underlying candidate genes associated with these seed traits. Hierarchical clustering based on DTF identified 67 spring-, 124 intermediate-, and 63 winter-type RILs. For TSW and SA, QTL were identified in Chr 2, 4, 8, 9, 11, and 13 with best logarithm of odds (LOD) of 5.74 (Chr11) explaining 7% phenotypic variation (PV) for TSW and LOD of 9.18 (Chr2) explaining 11% PV for SA. For CP, QTL were identified in Chr 2, 5, and 13, with best LOD of 10.75 (Chr5) explaining 14% PV. For TF, QTL were identified on Chr 9, 11, 13, and 17, with best LOD of 17.07 (Chr13) explaining 21% PV. For the FAs, QTL were identified in Chr 1, 2, 9, 10, 13, 15, 17, and 20, with best LODs of 9.94 (Chr 20), 9.5 (Chr1), and 5.95 (Chr13), respectively, explaining 13% PV for 18:2 and 18:3, and 8% for 20:1. Overlapping seed trait QTL on Chr8, 13 and 20 each contain one of the three paralogues of FLOWERING LOCUS C , highlighting its potential role as a candidate gene impacting regulation of camelina seed trait variation.