To develop faba bean germplasm that will be of economic value to the emerging faba bean sector by breeding for improved drought tolerance, low vicine/convicine, zero tannin, improved micronutrient availability, low phytate, improved resistance to chocolate spot, reduced height, small seed size and increased yield stability.
The overall goal of the research project was to develop methods and germplasm for modernizing faba bean breeding and production, thereby accelerating germplasm development to continue the expansion and improvement of the pulse-based component of sustainable cropping systems inSaskatchewan. Speeding up the introduction of faba bean is part of an overall strategy for extending crop rotations for pea and lentil – both crops are susceptible to Aphanomyces root rot. Faba bean provides excellent nitrogen fixation capability, and is in high demand as a plant-based protein source for the food and ingredient sector.
We developed new breeding techniques and germplasm to improve faba bean breeding systems with potential for improving three key agronomic traits – drought tolerance, chocolate spot resistance, and improved crop architecture. We also developed and implemented molecular marker based screening and laboratory measurement methods for substantially speeding up the breeding goal of reducing vicine-convicine in faba bean – the main antinutrient of concern in faba bean. These techniques will reduce barriers to food industry acceptance of faba bean as a source of plant protein ingredients. We also developed faba bean germplasm with improved genetic potential for developing resistance to chocolate spot, the main disease affecting faba bean. We also improved our genetic understanding of the basis genetics that influence the canopy architecture and stem structure of fab bean, thereby improving the potential for early season weed control and harvestability of the crop.
In general, the germplasm and population development for breeding and research are completed for all objectives. We screened and selected faba bean genetic materials for drought adaptation, vicine-convicine, micronutrient profile, chocolate spot resistance and crop architecture. We expect to continue research within the breeding program in future, especially for development of disease resistance and drought tolerance.
Objective 1 We investigated the nature and amount of genetic control of morpho-physiological traits related to drought adaptation in faba bean. Field experiments were used to select segregating germplasm, including RIL populations for improvement of chocolate spot resistance and reduction of seed size.
Objective 2 A rapid mass spectroscopy method and a molecular marker method were developed for determining vicine-convicine – these were tested and found to be robust. This aided our collaborating partners in NORFAB to elucidate the vicine-convicine biosynthetic pathway. We are now able accurately and quickly identify faba bean plants to greatly assist the effort to breed low vicine-convicine content.
Objective 3 A reliable KASP marker was developed and validated for the zt2 (white flower) gene, based on available EST sequences and a genetic map. The quality and repeatability of the marker was validated.
Objective 4 The field and in-door screening for reaction to chocolate spot infection showed that we have reliable and rich sources of resistance (see above). Genotypes displaying resistance tend to be late maturing, but this can be overcome through breeding for earliness while maintaining selection pressure for disease resistance.
Objective 5 We developed a solid genetic understanding of the faba bean branching and dwarfing. This will allow us to develop germplasm for specific cropping systems, for example, intercropping compatibility in organic systems, lodging tolerance, plant height and early weed suppression through basal branching
We published 10 manuscripts to date as part of the output of this grant. Additional manuscripts will be submitted in 2021.
In summary, we developed important major components of the basic genetic toolbox for modernizing faba bean breeding in the Saskatchewan environment, and for rapid expansion of the faba bean industry.
We developed 4 small-seeded, white-flowered low vicine-convicine faba bean varieties with high yield potential for production in the Thin Black, Dark Brown and Brown soil zones of Saskachewan. These are now at the stage of breeder seed production for potential release in 2022.
- We developed the necessary tools for rapid breeding of low vicine-convicine faba bean. The plant protein ingredient industry sector is fully engaged, plans to expand its use of faba beans for protein extraction.
- We completed the baseline assessment of micronutrient content of faba beans grown on the prairies. Faba bean is an equal or superior source of mineral micronutrients in comparison to the other pulse crops.
- We developed market appropriate germplasm suitable for improving chocolate spot resistance and developed a plan for using genetic markers to accelerate resistance breeding for the disease.
- We developed specific knowledge of the genetic basis for plant height, branching habit, and flowering time to the point where we can now design breeding strategies for breeding for shorter season regions in the northern crop production regions and drier regions in the south. Agronomic research with new genotypes can proceed.