1a.Objectives (from AD-416):
1. Continued selection and evaluation of soybean breeding lines for rust resistance.
2. Development of resistant germplasm.
3. Identification of qualitative and quantitative resistance genes/alleles.
4. Evaluation of the efficacy of putative resistance lines and germplasm.
1b.Approach (from AD-416):
Breeding lines have been developed from crosses with resistant lines. Evaluation and selection among these lines in field experiments with natural rust pressure will continue toward the development of new, improved resistant germplasm releases. Potential new sources of resistance will be evaluated in field screenings and new populations developed as warranted. The efficacy of single-gene resistance will be evaluated using fungicide spray/no spray field experiments. Similar fungicide experiments will be used to identify and evaluate quantitative resistance in a recombinant inbred population. Where appropriate, molecular markers will be used to identify specific genes and qualitative trait loci.
The primary objective of this research is to identify and develop rust resistant soybean germplasm. In this reporting period, field experiments were established at the Paraguayan research station Centro Regional de Investigación Agrícola, in Capitán Miranda, Paraguay. In addition to continued evaluation of breeding lines and populations segregating for rust resistance, the second year of a fungicide spray/no spray experiment with a recombinant inbred population was established to investigate quantitative genetics of rust tolerance. The data is now being analyzed. Additionally, a cooperating scientist from Paraguay spent six months at Stoneville, MS, assisting in the selection of breeding lines and harvesting seed plots.