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United States Department of Agriculture

Agricultural Research Service

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Location: Houston, Texas

2012 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 shipped to us by other project cooperators. During the current reporting period, we received over 4200 dry and snap bean seed samples. These samples came from plants grown in replicated field plots at six different locations across the US. Some of these plots were maintained without irrigation, in order to assess the effects of limited water supply on seed yield and seed nutritional value. The bulk seed samples were ground using stainless-steel grinders. Sub-samples of each are in the process of being acid digested for the analysis of elemental composition using ICP-OES (inductively coupled plasma – optical emission spectrometry). These digests and analyses should be completed by early 2013. Additional sub-samples were also sent to project collaborators to analyze protein, fiber, and oil, or phytate in the ground seeds. During the past year we also completed the analysis of iron availability, using a set of 248 bean samples grown in Washington State in 2010. This assay involved the use of an isolated cell culture system that can be used to determine how well a food sample (the ground beans) would aid in the absorption of dietary iron. The iron bioavailability data were shared with one of our project collaborators who performed statistical tests, using our iron absorption results and available genetic data on the bean lines. We were able to identify unique sections of the bean genome that appear to be associated with enhanced iron absorption potential. We are now in the process of trying to confirm these identified regions, by assessing the known genes in these genome locations and by designing further cell culture assays. The ADODR has monitored the activities and progress of the project through e-mails and phone calls with the Project Director (PD), as well as via monthly conference calls with the PD and the Project Executive Committee. The ADODR is a member of the Project Executive Committee; this committee met with the Project Advisory Committee in January 2012 at the Plant and Animal Genome XVIV 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, genetic testing procedures, and nutrient analysis methods, 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 third project year.

4. Accomplishments

Last Modified: 06/24/2017
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