Location: Tropical Crops and Germplasm Research
Project Number: 6090-21000-062-000-D
Project Type: In-House Appropriated
Start Date: Mar 12, 2023
End Date: Mar 11, 2028
Objective 1: Identify new sources of anthracnose and grain mold resistance through genome-wide association analysis of the NPGS tropical sorghum germplasm collection. 1.A: Establish an NPGS sorghum core collection from the Niger and Senegal collections based on genetic profile. 1.B: Identify new sources of host-plant resistance to anthracnose and rust in the subset of Niger and Senegal. 1.C: Identify new sources of host-plant resistance to grain mold in the subset of Niger and Senegal. 1.D: Identify new sources of host-plant resistance to anthracnose and rust in the sorghum Bioenergy Association Panel (BAP). Objective 2: Determine which resistance sources from NPGS tropical sorghum germplasm collection are present in temperate-adapted germplasm. 2.A: Establish an NPGS sorghum mini-core set collection using publicly available genetic information. 2.B: High-throughput molecular marker development for anthracnose resistance loci. 2.C: Genome-wide association analysis for anthracnose resistance loci in NPGS mini-core set. 2.D: Inheritance of grain mold resistance in the Sudanese accession PI 267548.
The focus of this research is to use genotypic and phenotypic characterization of National Plant Germplasm System (NPGS) sorghum tropical germplasm to identify new sources of resistance to anthracnose, rust, and grain mold. Publicly available genomic characterization of NPGS sorghum germplasm collections from Niger (516 accessions) and Senegal (421 accessions) will be used to select a core subset that represent their genetic diversity. This core subset will be phenotyped for agronomically important traits and resistance to anthracnose, rust, and grain mold. Genome-wide association analysis will lead to the discovery of new disease-resistance loci and the identification of valuable germplasm for sorghum breeding programs. In parallel, the bioenergy sorghum association panel (BAP; 390 accessions) will be evaluated for anthracnose and rust resistance. Genome wide association analysis will lead to the discovery of new resistance loci in this germplasm. To improve our understanding of the distribution of the anthracnose resistance loci in the NPGS germplasm collection, a representative mini-core set will be established using publicly available genomic characterization of core sets from Ethiopia (374 accessions), Sudan (318 accessions), Yemen (394 accessions), West and Central Africa (617 accessions), Niger (516 accessions), Senegal (421 accessions), sweet sorghum (272 accessions) and the BAP (390 accessions). This NPGS mini-core set will be genotyped with seven molecular markers associated to anthracnose resistance and evaluated for anthracnose resistance response. Genome-wide association analysis as well as multiple regression analysis based on anthracnose resistance markers will be conducted to identify new resistance loci and to determine the interaction between resistant loci. A recombinant inbred lines (RILs) population derived from the grain mold resistant Sudanese accession PI 267548 and the elite susceptible line RTx430 will be developed and used to study the inheritance of resistance response. The RILs population will be evaluated for grain mold resistance and genetically characterized based on genotype-by-sequence analysis to construct a linkage map. Genomic regions associated with grain mold resistance observed in PI 267548 will be identified using inclusive composite interval mapping. The biparental mapping populations developed in this project will be available for the scientific community and will provide new temperate-adapted germplasm for sorghum breeding programs.