2011 Annual Report
1a.Objectives (from AD-416)
Map abiotic resistance genes in soybean for iron deficiency chlorosis, drought, salt stress, aluminum tolerance, and ozone tolerance.
1b.Approach (from AD-416)
Approximately 200 random inbred lines at the F5 stage are ready for seed increase during the summer of 2010 to generate the seed stocks that will be used as material for subsequent evaluations of environmental stress resistance. DNA extraction will be performed and SNP markers will be generated for each random inbred line of the population. A linkage map for the population will be constructed from the DNA data. The population will be evaluated for drought, iron deficiency chlorosis, toxic soil aluminum, salt, and atmospheric ozone pollution, the association of each trait with DNA markers (QTL analysis) will be performed.
Independent preliminary research conducted by USDA-ARS in Raleigh, NC, and by the University of Minnesota identified a family of soybean genotypes from Fiskeby, Sweden, that are resistant or partially resistant to drought, iron deficiency chlorosis, toxic soil aluminum, salt, and atmospheric ozone pollution. A population developed from hybridization of Fiskeby III (representing the stress resistance of the Fiskeby soybean family) with Mandarin (Ottawa) (susceptible to drought, ozone, salt, and iron deficiency chlorosis, but resistant to aluminum) will be used to map resistance genes. The original hybridization was made in 2006 and seed of the resulting population were advanced by single seed descent.
This project is related to Objective 3 of the parent project to identify soybean germplasm that will contribute to development of stress tolerant cultivars.
The objective of this project is to map stress tolerance genes in soybean for five abiotic stress factors: drought, iron deficiency chlorosis, ozone, salt, and toxic soil aluminum. A mapping population of random inbred lines will be developed from a cross between tolerant (Fiskeby III) and sensitive (Mandarin Ottawa) genotypes. Each random inbred line will be assessed for response to each abiotic stress factor and these phenotypic data combined with deoxyribonucleic acid (DNA) marker data to construct linkage maps for each factor.
The seed increases for the mapping population of 240 random inbred lines were completed during the summer of 2010 in Minnesota and in a 2010-2011 winter nursery in Chile operated by our University of Minnesota cooperator. These seed sources are being used to phenotype the mapping population for abiotic stress response. Leaf tissue harvested from progeny rows in 2010 was used to isolate DNA for subsequent single nucleotide polymorphism (SNP) marker assay.
Screenings of the mapping population for both drought and iron deficiency chlorosis responses were begun by our University of Minnesota cooperator at field sites previously identified to exhibit these unique stress factors. The parental lines and other checks specific to the stress of interest were included in replicated field plots. Injury scores are being taken to provide the phenotype data required for mapping studies.
The project was monitored by email and telephone calls with the cooperating principal investigator.