Location: Dairy Forage Research
Project Number: 5090-21500-002-069-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2026
End Date: Aug 31, 2028
Objective:
1) Cooperator will evaluate forage yield and nutrition attributes, e.g. lignin content and digestion in native warm-season perennial grass populations developed by the ARS breeding program.
2) Cooperator will identify genetic regions associated with traits of interest and explore candidate genes and their functions.
3) Cooperator will assist the ARS breeding program in developing populations and variety candidates with improved forage yield and digestibility.
Approach:
Cooperator will establish a large diverse populations (n = 200) of Eastern Gamagrass (Tripsacum dactyloides L.) and Indiangrass (Sorghastrum nutans) obtained from the ARS Perennial Grass Breeding Program to be evaluated for cell wall and lignin composition. The plants will be phenotyped using high-throughput imaging techniques (e.g. infra-red, NDVI) to obtain high-resolution images. A subset of the population (~10%) will be tested with wet-lab chemistry to assess cell wall and lignin composition and structure. Relationship between the wet-lab results and data obtained from imaging will be explored to develop a predictive model for trait assessment in future populations. The populations will be genotyped using a sequencing-based approach and discovered markers will be used to characterize the underpinning genetic control of the traits. RNAseq will be carried out on two contrasting genotypes of each species to better understand the genetic control of the traits.
Separate, larger populations (n = 500) will be established, imaged, and predicted using the previously developed model to estimate trait values in the untested population. The best genotypes will be selected and recommended to the ARS breeder to make new crosses and progeny development for the purpose of variety development. All final data, models, and supporting information will also be provided to the ARS Perennial Grass Breeding Program.