Development of a pollination control system for Ethiopian mustard: introgression of the restorer gene into adapted germplasm

Posted on 23.03.2017 | Last Modified 07.05.2019
Lead Researcher (PI): Kevin Falk
Institution: Agriculture & Agri-Food Canada
Total WGRF Funding: $98,764
Co-Funders: Agriculture Development Fund
Start Date: 2013
Project Length: 3 Years

To improve the yields of the potential Ethiopian mustard (Brassica carinata) hybrids to meet market standards and to promote better adaptability to Saskatchewan growing conditions.

Project Summary:

Ethiopian mustard is an emerging crop well suited to production on the prairies of western Canada. In order to maximize yield in this species work was undertaken to develop a pollination control system which would enable the development of hybrids. Using a system currently used in canola and Oriental mustard, the Rf gene (restorer) was transferred into Ethiopian mustard from Oriental mustard. Rf is required to restore fertility to male sterile plants and is the main feature of so-called R-lines. Our original attempt at transferring Rf to carinata was successful in that plants were fully restored.  However, the seed pods were significantly smaller and the number of seeds per pod was reduced. In order to remedy this, crosses were initiated along with molecular marker work to track and speed the integration of ‘long pod’ and ‘Rf’. In addition, BC1 plantlets from the earliest crosses were tested to isolate lines which potentially had smaller genetic insertions. Finally another ‘altered copy’ of the Rf gene was transferred from Oriental mustard or Brassica juncea. This copy of the gene is much smaller than the original and the integration was thought to disrupt fewer, if any, traits such as pod length and the number of seeds per pod.  This work resulted in three unique lines/sources which in combination improved pod length and the number of seeds per pod. In conclusion, we have successfully increased the pod length using a combination of the three sources mentioned above. Further work is ongoing to stabilize the trait as well as transfer the improved Rf to agronomically superior genetic backgrounds.