A Soybean Germplasm Evaluation Study for Seed Compostion and Agronomic Traits in Rwanda.

The Government of Rwanda has designated soybean a priority crop through its crop intensification program (CIP) under the Ministry of Agriculture. Soybean is cultivated in the East, West and Central regions of Rwanda and contributes to food security, combating malnutrition, income generation as well as improving soil fertility, although there currently exists a need to develop improved soybean varieties.  The objectives of this study are to a) develop a genome-wide association study for mapping seed composition and agronomic traits, b) understand soybean adaptability in Rwanda, and c) develop Kompetitive Allele Specific (KASP) SNP markers for soybean rust resistance genes. For the 2016 season, 1007 diverse plant introductions (PI), ranging from MG III to MG X, will be grown in Rwanda to determine the most useful PI’s to be grown in a replicated, multiple year and location field experiment during the 2017 and 2018 seasons. Of the 1007 lines, 291 have elevated protein, 284 have elevated oil and 170 contain at least one of the previously identified rust resistance genes.  Phenotypic data such as seed color, protein and oil concentration, plant height, maturity date, flowering date, lodging, and seed weight will be collected. 400 to 500 of the best performing lines will be used to conduct a genome-wide association study (GWAS) using the 50K SNP chip and whole genome sequence data. We shall simultaneously conduct an adaptability study to determine suitable germplasm for the Rwanda environment of 1000-1500 meters above sea level, 2° 36' S, 29° 44' E, annual rainfall of 800 – 1000 mm and temperature ranging from 18 to 24 °C.  KASP PCR SNP markers shall be developed for the rust resistance genes for use in marker assisted selection. This germplasm set will serve as a source for agronomic and seed composition traits and all currently identified soybean rust resistance genes to Rwanda and the East African region.