• Dry Beans
• Disease Management
• Pulse Science Cluster
• Root Rots

Objective

To develop dry bean germplasm and varieties with improved resistance against common bacterial blight and anthracnose, and tolerance to white mould and root rot; to investigate the genetic diversity and population structure of bean breeding germplasm; to study the genetics of resistance to multiple diseases; to determine the genetic diversity between/within the gene pools of bean for nodulation and symbiotic nitrogen fixation (SNF) potential and identify genotypes with high N2 fixation potential; to explore the genetic basis of SNF in bean and map genomic regions involved; to develop non-darkening or slow darkening high-yielding cranberry bean varieties; to identify gene-based markers for selecting for the non-darking trait derived from Witrood.

Outcome

The overall objective of this activity is to address dry bean production constraints to maximize economic returns to growers and ensure long term sustainability of the dry bean industry in Canada by developing adapted bean varieties, with multiple disease resistances, higher yields, greater nitrogen use efficiencies and improved seed quality. Several biotic and abiotic factors pose significant risks to the bean production industry in Canada. Therefore, the project targeted the development of bean varieties with reduced risk and with reduced dependence on pesticides and fertilizers, leading towards the development of more sustainable bean production practices in Ontario. The work included broadening bean germplasm diversity by conventional plant breeding, advancing the material to a true breeding condition and extensive testing for yield, maturity, plant architecture, disease resistance, canning suitability, nitrogen fixing capacity and seed coat colour. In addition, the work included the development of bean germplasm that doesn’t darken after harvesting since darkening reduces the commercial value of light coloured beans like cranberry and pinto beans. The breeding program produced 150 - 250 new crosses annually among navy, black, cranberry, kidney and pinto bean market classes. The materials were advanced to homozygosity by: bulk advances of 800 F2-F5 families, selecting single plants from the F5 families, testing selections in in-house yield trials for two years and testing the best lines in provincial registration trials for two years. Typically, 10-15 lines were entered into the provincial trials and 1 - 4 lines were supported for registration each year. The bean breeding program developed navy bean lines with resistance to common bacterial blight (CBB) (e.g. 'Mist') as well as anthracnose resistant white bean varieties such as 'Bolt'. Our most recently developed lines navy bean lines (like 'Fathom' and 'Argosy') combine both resistances into single varieties. This combination of disease resistance characteristics in dry bean will mitigate economic losses and reduce pesticide use, thus protecting the environment and Canadian consumers. Bean diseases, such as common bacterial blight and anthracnose, are responsible for 10% losses in crop yields annually (~$25 M). This is in spite of spending on average over $25/ acre on disease control agents. The high yielding kidney bean variety 'Yeti' was also developed by this program. Genetic information is fundamental to make advances in bean breeding. The information that was obtained about the genetic relatedness among accessions in Ontario bean germplasm is critical for making decisions about which materials to use in crosses and the insights that we have obtained from genetic studies of traits, like common bacterial blight resistance and seed coat darkening, provided tools for selection that allow us to be more precise and efficient in identifying individuals with desired characteristics. Single nucleotide polymorphisms significantly associated with yield, maturity, common bacterial blight resistance and anthracnose resistance were identified.

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