Location: Cereal Crops Improvement Research
Project Number: 3060-21000-046-013-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Jan 1, 2022
End Date: Dec 31, 2024
Objective:
The overall objective of this research is to leverage high-throughput genotyping and phenotyping technologies to accelerate wheat improvement. The objectives of the ARS, Fargo, ND portion of the research are to 1. Identify novel genes and QTL associated with yield and biomass traits in hard red spring wheat; and 2. Clone a gene responsible for increased spike weight and grain number in durum wheat.
Approach:
Research will be conducted to identify and characterize QTLs associated with grain yield and other important agronomic traits in HRSW. We currently have a biparental population consisting of about 2,000 F6-derived RILs derived from the elite North Dakota HRSW variety ‘Faller’ and a HRSW variety from China named ‘Jinqiang 5’ (JQ5). JQ5 has been included in four environments of ND yield trials. JQ5 has fewer tillers and yields slightly less than Faller, but it matures eight days earlier, is 18 cm shorter, has larger seed, and has end-use quality parameters very similar to Faller. Therefore, this population provides the opportunity to identify QTLs associated with enhanced yield in Faller, which may be representative of those in much of the ND HRSW breeding material, and also to identify unique combinations of alleles that could result in new shorter, earlier maturing, and high yielding ND HRSW varieties. Varieties that mature earlier without suffering yield/quality reductions are becoming more important in ND due to frequent wet springs that lead to later plantings. Having access to 2,000 RI lines is a major benefit to this project in that it provides a large number of lines for observations and selections of lines with the best combinations of traits, and the large number of lines will be extremely beneficial for high-resolution mapping and cloning of desirable QTLs.
We will grow the entire population in the field this summer (2021) at one location and take notes on yield, agronomic, and disease-related traits to take inventory of all the segregating traits. After the project has officially started, we will randomly select 200 RILs and genotype the RILs with the Illumina 90k arrays, phenotype the RILs under both field and greenhouse environments, and do QTL analysis to identify genomic regions associated with important traits. QTLs of high interest will be targeted for high-resolution mapping for breeder-friendly marker development and potential map-based cloning. The markers will also be employed for marker-assisted backcross introgression of the QTLs into other adapted lines. All 2,000 RILs will be grown in several field environments and phenotypic observations made. RILs that fit the targeted ideotypes of the ND HRSW breeding program will be selected and genotyped to determine which carry the desired alleles at target QTLs. These selections may be incorporated directly into the breeding program for varietal development. We feel that this project spans the molecular genetics/plant breeding/genotyping/genomics spectrum and will lead to interesting genetic discoveries (research articles) and will have a direct impact on the HRSW breeding program varietal development.
We will also continue work to clone the QTL on chromosome 2B associated with number of grains per spike and spike weight. We will be phenotyping about 100 BC3F4 homozygous recombinants this summer to further narrow the candidate region. The process of screening with flanking markers to identify recombinants and phenotyping the recombinants to further narrow the region will continue until a suitable number of candidate genes are identified.
