Preserving hybrid vigour through a novel apomixis breeding strategy in Brassica crops
Term: 5 years, ending 2023
Status: Complete
Researcher(s): Tim Sharbel, Martin Mau, U of S
SaskCanola Investment: $71,760
Total Project Cost: $633,360
Funding Partners: ADF
Grower Benefits
The establishment of apomixis (asexual seed) formation in Canola will enable the immediate genetic fixation of hybrid vigor, and the rapid generation of varieties with combinations of favorable traits not achievable using available breeding methods.
Researchers provided proof of stable inheritance of unbalanced apomixis across several backcross generations in the model plant Boechera, a wild apomictic relative of Canola. These valuable backcrosses minimize the effort to identify all genetic factors for apomixis simultaneously by comparative analysis of common paternal (i.e. apomictic donor) genome fragments in the final backcrosses.
Generation of the first intergeneric hybrids between an apomict (i.e. Boechera) and Canola (i.e. Brassica napus cv ‘Golden’) and introgression of subsets of apomixis candidate factors demonstrates proof of concept that engineering of apomixis in Canola is possible.
Project Summary
Engineering apomixis, the asexual reproduction through seeds without fertilization, will provide major advances to plant breeding. This is a technology which could quickly capture and maintain valuable genotypes and associated traits without inbreeding depression and help select for traits not available to current breeding strategies. This could potentially mean that breeding for certain traits or creating genetically pure breeding material would take less time in the future resulting in farmers having access to new cultivars more rapidly.
Researchers built off a previous project to transfer the apomixis trait from Boechera (a Brassica relative) lines directly into multiple Brassica crops. In this current project, researchers successfully backcrossed several Boechera lines to produce 12 near-isogenic lines (NILs) with reduced genomic proportion from the apomictic father that contain all required genetic factors to trigger the apomixis trait. Genomes of both parental and NILs are currently used to find novel and validate known apomixis candidate factors.
Researchers also explored crossing Boechera into a close relative crop to potentially trigger the apomixis trait in the crop plant directly. Researchers were successful at the introgression of Boechera sp. genomic regions into canola and validated the introgression. Further research is needed to finalize the transfer of apomixis to Canola.