NDSU research leads to better bean-breeding strategies
Posted on 6/13/2014
Two NDSU scientists are members of a national research team that successfully completed the sequence of the common bean genome. North Dakota is the leading producer of dry beans in the US.
The NDSU team members are Phil McClean, plant genomicist, and Juan Osorno, dry edible bean breeder. Both scientists are faculty members of the NDSU plant sciences department.
McClean guided the data analysis that determined that the domestication of the common bean in Mexico and the Andean region of South America involved almost completely different sets of genes.
Osorno organized a national field trial that identified regions of the genome associated with seed size and other traits of economic importance.
"The genome sequence has important implications for North Dakota agriculture because the state produces 30 percent of this billion-dollar crop," Osorno says. "The sequence will help breeders release varieties that are competitive with other crops a producer can grow. This includes breeding a more climate-resilient bean."
The sequence revealed that disease resistance genes are highly clustered in the genome. This knowledge will lead to better breeding strategies to combat the many diseases that challenge the bean crop.
McClean and Osorno are cooperating locally, nationally and internationally with other bean breeders and geneticists to develop the next generation of molecular markers that will be another important tool to aid bean breeding worldwide.
For the study, the team sequenced and assembled a 473-million basepair genome of the common bean. Though it is thought to have originated in Mexico more than100,000 years ago, the common bean was domesticated separately at two different geographic locations in Mesoamerica and the Andes.
The team then compared sequences from populations representing these regions and discovered only 59 out of 27,000 shared domestication genes. This indicated that different events were involved in the domestication process at each location.
"These results will allow us to focus our attention on a specific subset of genes as we look for genomic regions important for the improvement of the many bean market classes," McClean says.
From a global perspective, this information could be beneficial to farmers in developing countries that practice the intercropping system known as "milpa," in which beans, corn and, occasionally squash, are planted together. The practice ensures that their land will continue to produce high-yield crops without resorting to adding fertilizers or other chemical methods of providing nutrients to the soil.
"In addition, as breeders and genomic scientists in other countries work with NDSU to utilize this important new genetic resource, other production constraints unique to the milpa system can be addressed," McClean says.
McClean and Osorno worked in collaboration with project leader Scott Jackson from the University of Georgia, Dan Rokhsar of the U.S. Department of Energy Joint Genome Institute and Jeremy Schmutz of the DOE's Joint Genome Institute and HudsonAlpha Institute for Biotechnology.
Other NDSU personnel on the project are postdoctoral scientist Sujan Mamidi and graduate student Samira Mafi Moghaddam. Both are members of McClean's research group.
The project was supported by the U.S. Department of Energy and U.S. Department of Agriculture.
The common bean research was published in "Nature Genetics" journal. McClean was a co-lead author of the article.
NDSU is recognized as one of the nation's top 108 public and private universities by the Carnegie Commission on Higher Education.