Location: Crop Genetics and Breeding Research
Project Number: 6048-21220-020-000-D
Project Type: In-House Appropriated
Start Date: Mar 12, 2023
End Date: Mar 11, 2028
Objective:
Objective 1: Identify and develop new sources of maize germplasm and molecular markers for traits such as reduced aflatoxin accumulation, increased pest resistance, and enhanced agronomic performance under drought and heat stresses.
Sub-Objective 1A. Evaluate exotic maize germplasm lines from Africa, the Germplasm Enhancement of Maize (GEM) program, International Center for the Improvement of Maize and Wheat (CIMMYT), and the U.S. maize germplasm collection for resistance to insects and Aspergillus flavus infection, and reduced aflatoxin accumulation.
Sub-Objective 1B. Develop maize germplasm with enhanced agronomic performance, increased resistance to insects and A. flavus infection, and reduced aflatoxin accumulation for the Southeastern Coastal Plain region.
Sub-Objective 1C. Develop molecular markers for resistance to insects and A. flavus infection, and reduced aflatoxin accumulation in maize, and utilize molecular markers for gene identification, as well as cultivar and germplasm enhancement.
Objective 2: Identify and develop new sources of sorghum germplasm and molecular markers for traits such as anthracnose and multiple insect resistance, high sugar content, low lodging, high yield, and complementary maturity genes.
Sub-Objective 2A. Evaluate sorghum lines from the Ex-PVPs and the U.S. germplasm collection for resistance to anthracnose and insects.
Sub-Objective 2B. Develop sorghum germplasm with improved anthracnose and insect resistance and high yield potential for the Southeastern Coastal Plain region.
Sub-Objective 2C. Develop molecular markers for anthracnose and insect resistance in sorghum, and utilize the markers for gene identification, as well as cultivar and germplasm enhancement.
Approach:
Objective 1: Unique/exotic maize germplasm lines from diverse sources will be continuously screened for resistance to multiple pests, and reduced aflatoxin contamination. To effectively serve the seed industries, the screenings of maize insect pests will focus on key foliar-, ear- and kernel-feeding insects, in particular, fall armyworm, corn earworm and maize weevil. New maize breeding crosses will be made by recombining germplasm with good agronomic traits, drought/heat tolerance (stay-green trait) with the newly identified germplasm that confers multiple insect and disease resistance and with reduced mycotoxin contamination. New maize germplasm will be developed by continuously screening and continuous self-pollination of the segregating populations. At the same time, a population of recombinant inbred lines (RILs) will be screened in replicated experiments for reduced aflatoxin and resistance to insects and diseases to identify DNA markers for use in breeding multiple pest-resistant maize germplasm lines.
Objective 2: A similar approach is utilized for the screening of sorghum germplasm for resistance to multiple biotic and abiotic stress factors. Previously identified drought and heat tolerant (with stay-green trait), disease resistant, and with agronomically-elite germplasm (from Ex-PVP program) in the U.S. germplasm collection will be screened for resistance to sorghum aphid, fall armyworm, foliar anthracnose disease, and sorghum midge. New sorghum breeding crosses will also be made using sorghum germplasm lines identified under the previous project that are resistant to multiple biotic stresses and with good yield potential. The breeding crosses will be continuously screened, selected, and self-pollinated to develop and release new sorghum germplasm lines (B lines, or maintainer lines). The best B lines will also be converted into A lines (or cytoplasmic-nuclear male sterile lines) to serve the seed industries. At the same time, the genetic basis for insect and disease resistance will be examined by screening a sorghum RIL population in replicated experiments for resistance to sorghum aphid, grain mold, and other biotic stresses. DNA markers will be identified for use in future breeding efforts.
