Location: Hard Winter Wheat Genetics Research
Project Number: 3020-21000-011-042-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2022
End Date: Aug 31, 2025
The objective of the project is to identify drought tolerance traits in winter wheat breeding germplasm carrying introgressions from wheat wild ancestors, Triticum dicoccoides and Aegilops tauschii, using field drought phenotyping at the Agricultural Research, Development, and Education Center (ARDEC; Fort Collins, CO) and at the Limited Irrigation Research Farm (LIRF; Greely, CO). The project will integrate phenotypic evaluation with crop modeling and genomic data to identify drought tolerance alleles useful for breeding of drought-tolerant wheat.
The cooperator will conduct two experiments in two crop years, a stress parameterization trial and a screening trial. Trials will be conducted at LIRF and ARDEC on ~ 2 ac parcels grown in rotation with spring barley. Trials will be irrigated at planting to ensure consistent crop establishment. The experimental unit will be 6 rows and 11 ft long with alleys of 3 ft. The target plant population will be 500000 plants/acre with 123 seed/m2. The stress parameterization trials will be conducted at LIRF and ARDEC. This experiment will comprise 20 genotypes (10 elite lines and 10 commercial varieties, selected jointly between ARS and cooperator) with eight replications under well-watered and rainfed treatments which will be planted in a split plot design where main plots are irrigation treatment and subplots are a randomized arrangement of genotypes. Traits evaluated under well-watered conditions will be used to benchmark the plasticity of measured traits under dryland conditions. The screening experiment will comprise 150 experimental genotypes and 8-10 checks (selected jointly between ARS and cooperator) planted under rainfed conditions with four replications under an augmented design in a randomized complete block. During the growing season, the cooperator will collect observations of plant height, number of fertile tillers in a row/plot, flowering time, physiological maturity, and grain filling period. At physiological maturity, the cooperator will evaluate yield components via destructive sampling. The cooperator will collect twenty-five spikes per plot in a random sample to collect spikelet number, kernels/spike, thousand kernel weight, biomass, and harvest index (HI). The cooperator also will use additional non-destructive and high throughput phenotypic methods to test other drought adaptation traits that can contribute to drought stress, including stay green (NDVI) and limited transpiration (canopy temperature). Field data will be analyzed using mixed linear models and principal component analyses. The cooperator agrees to envirotype (i.e. define major environment patterns) the drought stress patterns for winter wheat in the western plains (eastern CO, western KS, western NE). This study will be of immediate value to target specific stress patterns for managed drought field phenotyping, and long-term value to guide drought tolerance breeding decisions in the region. The cooperator will perform seasonal winter wheat simulations using a process-based approach, estimating plant water demand and soil water supply. For these simulations: 1. The cooperator will characterize the growth and development of a predominant winter wheat variety using existing field data. 2. Arrange environmental information that affects crop development (climate and soil). 3. Document main crop management practices for winter wheat in the growing season. Winter wheat seasonal simulations will be conducted for over 30 years of environmental data. Seasonal water stress patterns (plant water demand vs. soil water supply) will be analyzed via a hierarchical cluster analysis to identify major water stress patterns in the winter wheat producing regions.