Location: Sunflower and Plant Biology ResearchTitle: Fine mapping to identify heterotic gene(s) for increasing yield in canola
|ZHENG, PUYING - North Dakota State University|
|RAHMAN, MUKHLESUR - North Dakota State University|
Submitted to: Popular Publication
Publication Type: Popular Publication
Publication Acceptance Date: 7/22/2020
Publication Date: N/A
Technical Abstract: The use of heterosis (as known as hybrid vigor) is one effective way to increase crop yield by enhancing superior performance in F1 hybrids generated by crossing two inbred parents. Over the last three years, progress made towards achieving the objectives of this proposal includes: 1) Testing grain yield and yield-related traits under field conditions for canola hybrids resulting from crossing between 8 introgression lines (ILs) and Westar, and 2) Confirmation of the heterotic gene(s) within a mapped 26-kilobase (Kb) region. These objectives have been completed, and the heterotic gene(s) within the 26-Kb region have been confirmed. Previously, we identified a heterotic locus in F1 hybrids from a cross between ‘Westar’ (canola, Brassica napus L.) and a Chromosome Segment Substitution Line (CSSL). The CSSL has the genetic background of Westar introgressed with a segment of chromosome A10 from ‘Surpass 400’. To map the heterotic gene(s) within this identified locus, a set of eight ILs were developed that carry different lengths of DNA segments from chromosome A10 of ‘Surpass 400’. These ILs were reciprocally crossed with Westar, and the resulting 16 F1 hybrids, along with their parents, were planted for three years (2017: Fargo and Prosper, ND; 2018: Fargo and Langdon, ND; 2019: Fargo) to estimate heterotic effects. A total of 36 entries (16 IL x Westar reciprocal hybrids, 8 ILs, 8 Westar, 2 CSSL x Westar reciprocal hybrids, 1 CSSL, and 1 Westar) were sown per replicated field plots. Grain yields were compared based on the results of eight IL groups from the 36 entries. Based on the three-year grain yield results and the known position and length of introgressed segments, the gene(s) associated with the heterotic trait have been mapped to a 500-Kb region between two molecular markers at 14.5 and 15.0 megabase in chromosome A10. However, additional sequencing technology (called genotyping) helped narrow the heterotic gene(s) to within a 26-Kb region. Further sequencing of this 26-Kb region will help to identify the candidate gene(s) involved in the heterotic trait of canola hybrids. Genetic transformation of canola with these candidate heterotic gene(s) will help to confirm the molecular mechanism regulating heterosis, which should provide canola breeders with new knowledge for increasing grain yield.