Identification of flowering time QTL in a Camelina biparental population developed from winter-and spring-type parents

Authors: Sthapit Kandel, Jinita; Talukder, Md Zahirul; SHAIKH, TM - University Of Missouri; Horvath, David; LI, XUEHUI - North Dakota State University; Anderson, James

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Camelina is an annual oilseed crop that has both spring and winter biotypes. Winter types have exceptionally low-temperature tolerance and can be planted in the fall and harvested early in the summer providing opportunities for multi-cropping options in the northern Great Plains. Early maturing varieties of camelina allow for an earlier harvest and subsequent planting of a second commodity crop in the same growing season. A population of camelina lines developed from crossing a winter and a spring-type parent were evaluated for the variation in their flowering time. This helped identify early maturing lines of camelina. Genetic analysis identified regions in seven chromosomes of the camelina genome that are associated with flowering time. Exploration of these genetic regions identified potential genes known to regulate flowering time. This information will allow breeders to develop and integrate earlier maturing camelina lines, which will provide growers with better multi-cropping options.

Technical Abstract: Camelina [Camelina sativa (L.) Crantz] is an annual oilseed crop from the Brassicaceae family. Camelina consists of both spring- and winter-biotypes with winter biotypes having exceptionally low temperature tolerance. Winter-hardy crops, such as camelina, can be planted in the fall and harvested early in the summer allowing for double- and relay-cropping options in the northern Great Plains of the USA. To enhance double- and relay-cropping systems, early maturing varieties of camelina are desired. The objectives of this study were to evaluate variation in flowering time and identify quantitative trait loci (QTL) in a biparental camelina population developed from crossing a winter (Joelle) and a spring (CO46) biotype. An F7 recombinant inbred line (RIL) population consisting of 254 individuals was phenotyped for days to flowering (DTF) under greenhouse conditions after treatment with or without 8-weeks of vernalization. Variation in DTF among two experiments (Exp) was observed in the RIL population and average DTF for non-vernalized plants were 46.8 and 51.2 days after planting (DAP) (Exp 1 and 2 respectively) and 89 to 90.1 DAP in vernalized plants. Broad-sense heritability estimate of DTF across two experiments was 0.79 with and 0.92 without vernalization. The RIL population was genotyped with 2412 SNP markers to create a linkage map and perform QTL analysis. The map consisted of 20 linkage groups representing the 20 chromosomes (Chr) of C. sativa. QTL analysis of DTF with vernalization identified significant loci on chromosomes 2, 8, 11, 13, and 16 with the highest LOD (logarithm of odds) score of 27.3 in Chr13 that explained 27% of phenotypic variation. For DTF without vernalization, QTL were identified on chromosomes 7, 8, 9, and 13 with the highest LOD score of 48.9 on Chr13 that explained 48% of phenotypic variation. Exploring the major QTL regions on chromosomes 8 and 13 of camelina indicated the presence of a MADS-box protein encoded by FLC (FLOWERING LOCUS C). Other candidate genes responsible for flowering time identified in the QTL regions include PEPB family protein, TGACG motif-binding factor 4, AGAMOUS-like MADS-box proteins (AGL16, AGL17, AGL18, AGL71, AGL72), CONSTANS-like 3, an RNA-binding protein (HLP1), SHORT VEGETATIVE PHASE (SVP) gene, and a subunit of the mediator complex that affects flowering time and floral organ formation. These RILs provide an important resource for developing early maturity varieties of camelina.