Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2018
Publication Date: 2/14/2018
Citation: Cuevas, H.E., Prom, L.K., Rosa, G.M. 2018. Population structure of the NPGS Senegalese sorghum collection and its evaluation to identify new disease resistant genes. PLoS One. 13(2). e0191877. Available: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0191877.
Interpretive Summary: Sorghum yield can be significantly reduced by the effects of anthracnose (Colletotrichum sublineola) and grain mold diseases (multiple fungi). Therefore, a total of 158 NPGS Senegal accessions were evaluated for anthracnose and grain mold resistance at two locations to identify new genetic sources of resistance to both diseases. We identified 14 accessions resistant to grain mold and 8 to both diseases. Genetic analysis using molecular markers divided these 158 accessions into 4 populations suggesting the presence of few resistant sources to both diseases. The integration of highly genetically diverse germplasm with anthracnose and grain mold resistant into sorghum breeding programs should aid in the development of new disease-resistant varieties.
Technical Abstract: Sorghum germplasm from West and Central Africa is cultivated in rainy and high humidity regions and is an important source of resistance genes to fungal diseases. Mold and anthracnose are two important biotic constraints to sorghum production in wet areas worldwide. Here, 158 National Plant Germplasm System (NPGS) accessions from Senegal were evaluated for agronomic traits, anthracnose, and grain mold resistance at two locations, and genetically characterized according to 20 simple sequence repeat markers. A total of 221 alleles were amplified with an average of 11 alleles per locus. Each accession had a unique genetic profile (i.e., no duplicates), and the average genetic distance between accessions was 0.42. Population structure and cluster analysis separated the collection into four populations with pairwise FST values >0.15. Three of the populations were composed of Guinea-race sorghum germplasm, and one included multiple races. Anthracnose resistant accessions were present at high frequency and evenly distributed among the three Guinea-race populations. Fourteen accessions showed resistance to grain mold, and eight were resistant to both diseases. These results indicated that the NPGS of Senegal is a genetically diverse collection with a high frequency of disease resistant accessions. Nevertheless, its population structure suggests the presence of few sources of resistance to both grain mold and anthracnose, which are fixed in the germplasm. The phenotypic and genotypic information for these accessions provides a valuable resource for its correct use to broaden the genetic base of breeding programs.