Location: Houston, Texas2011 Annual Report
1a. Objectives (from AD-416)
This project will integrate research, extension, and education activities to develop new breeding material or improved breeding tools in common bean, with the goal of enhancing nutritional traits in this crop. An association mapping population consisting of 400 diverse lines, representing the major US market classes, will be evaluated for a number of nutritional traits including minerals, protein, carbohydrates, fiber, vitamins, health-beneficial phytochemicals, and differences in iron bioavailability. All of the lines will be genotyped, using currently available molecular markers, and the phenotype and genotype data will be used to discover regions of the genome that affect the nutrient traits. This will be accomplished using modern association mapping techniques, and will lead to the development of readily scorable molecular markers that bean researchers can use to breed new bean cultivars with enhanced nutritional quality.
1b. Approach (from AD-416)
Mineral concentration and iron bioavailability studies will occur on seed samples of common bean using ICP-OES (inductively coupled plasma – optical emission spectroscopy) or an in vitro model system (Caco-2 cells). The CNRC will analyze approximately 9,600 bean samples using ICP-OES and as many as 600 samples using our Caco-2 iron bioavailability model.
3. Progress Report
Our major activities in this project are to analyze mineral concentrations and iron bioavailability potential in the dry bean and snap bean samples that have been (and will be) shipped to us by other cooperators. During the current reporting period, we received dried tissue samples for 142 snap bean entries (times 3 field replicates) from our cooperator at Oregon State University. These entries were ground and processed (acid digested) for the analysis of elemental composition using ICP-OES (inductively coupled plasma – optical emission spectrometry). Our results indicate broad variation across the entries in both macro- and microelements, with ranges of: approximately 2- to 2.5-fold for Ca, K, Mg, Ni, P, S, and Zn; approximately 3-fold for Cu and Fe; approximately 5-fold for Se; and approximately 7-fold for Mn. These ranges of values bode well for future association mapping efforts directed towards the identification of genomic regions linked to these mineral traits. During the reporting period, we also received seed samples of 248 dry bean entries (approximately 150 grams each) grown in field plots in Michigan and approximately 150 gram samples of the same 248 entries grown in field plots in Washington State. These samples have been ground in stainless steel mills. From these bulks, 100 grams of each entry (times two locations) were sent to a cooperator at North Dakota State University for protein, fiber, and oil analysis, and 15 grams of each were sent to ARS-East Lansing for phytate analysis. We have completed the digestion and subsequent elemental analysis on both the Michigan and Washington State dry bean samples. Our results indicate broad variation across the dry bean entries, as well, with ranges of: 1.5- to 2.0-fold for K, Mg, P, and S; 2.0- to 2.2-fold for Fe, Mn, Cu, and Zn; 3.6-fold for Se; 9.5-fold for Ca; and 10.2-fold for Ni. The values for individual entries, along with the snap bean data, will be deposited in a publically available database. Finally, we have begun to assess iron availability potential from the Washington State grown set of dry bean entries, using the Caco-2 cell culture system. These analyses will be completed in late 2011. The ADODR is a member of the Project Executive Committee; this committee met with the Project Advisory Committee in January 2011 at the Plant and Animal Genome XVIII Meetings in San Diego, CA. Progress reports for all facets of the project were presented to the Advisory Committee; this Committee subsequently gave various technical recommendations to the PD and the Executive Committee. Minor issues, relating primarily to data handling and methods development, were responded to by the Executive Committee. The ADODR was also involved in reviewing the Project Annual Report sent to USDA-NIFA at the end of the second project year.