Performing Department
(N/A)
Non Technical Summary
The changing climate is bringing back complex biotic and abiotic constraints resulting in crop yield losses. Due to the narrow genetic base of the hexaploid wheat and limited gene flow from wheat progenitors and wild relatives, the genetic diversity of cultivated wheat is highly restricted. To develop climate-resilient wheat varieties for future food security, there is a dire need to preemptively explore and introgress novel abiotic and biotic stress tolerance traits in the wheat breeding programs. Among wheat wild relatives, Aegilops umbellulata has a high tolerance to abiotic and biotic stresses, which has not been explored in detail. Through this seed grant, North Dakota State University researchers will develop new genetic and genomic resources for the future transfer of valuable stress tolerance traits from Ae. umbellulata to wheat varieties.
Animal Health Component
0%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
0%
Goals / Objectives
Thegoals of the seed grant are to develop genomic resources and germplasm (core set of collection and synthetic hexaploids) for future exploration of multiple novel genes/traits in Ae. umbellulata. The current and follow-up projects will continuously supply valuable traits to wheat breeding programs for their deployment in wheat varieties. The proposed research will broaden the wheat genetic diversity by enriching the traits toolbox, thereby preparing the scientists to address future challenges posed by climate change and bring sustainability. The project goals will be achieved under the following objectives:1. Development of genetic, genomic, and germplasm resources in Aegilops umbellulata.2. Assessment of stress tolerance in Aegilops umbellulata and identification of associated genomic loci.
Project Methods
Objective 1: Development of genetic, genomic, and germplasm resources in Aegilops umbellulata.Method 1:An Ae. umbellulata line, NDRL21-044, resistant to multiple fungal pathogens, will be used to develop a chromosome-scale reference genome using PacBio and Oxford Nanopore Technologies long-read sequencing andHi-C chromosome conformation capture-based scaffolding.For genome annotations, we will generate PacBio Iso-seq RNA sequencing data from five tissue samples such as seedling leaf, seedling root, seedling leaf after vernalization, flag leaf, and immature spike.The complete reference genome will be available to the scientific community for future comparative genomics, and gene identification studies.Method 2:We propose to genotype our global collection of 396 accessions using tunable Genotype-by-sequencing (tGBS) to develop a core set of accessions representing maximum genetic diversity and perform genome-wide association studies (GWAS).The SNP genotypic data of 396 accessions will be used in proposed and future association genetics studies.Method 3:We propose to develop synthetic hexaploids (2n=6x=42, AABBUU) by crossing Ae. umbellulata genotypes with tetraploid wheat.Three tetraploid wheat genotypeswill be used as female parents to cross with six Aegilops umbellulata accessions carrying resistance to multiple wheat diseases. The intergenetic hybrid embryos will be rescued on culture media and F1 plants will be cytologically evaluated.Objective 2:Assessment of stress tolerance in Aegilops umbellulata and identification of associated genomic loci.Method 1:We propose to phenotype the complete set of 396 accessions with individual leaf rust races, MNPSD, TDBJQ, TBBGS, and TNBJS (races prevalent in the midwestern U.S.) at the seedling stage in replicated trials.Plants will be inoculated at two-leaf stage (10-14 days after planting) with fresh urediniospores and rated for infection types (ITs) 12-day post-inoculation (dpi) using the 0 to 4 scale.The GWAS will be performed using Genomic Association and Prediction Integrated Tool (GAPIT) version 3.0.The results will identify existing (Lr9 and Lr76) and novel genomic loci associated with leaf rust resistance.Method 2:To study heat tolerance in Ae. umbellulata, we will first set up a pilot experiment using six accessions selected for interspecific hybridization in objective 1. Later, a limited core subset of 50 Ae. umbellulata lines representing genetic and geographical diversity will be studied.Ae. umbellulata seeds will be started in potting mix and maintained in walk-in Conviron growth chambers at AES greenhouse facility in Fargo, ND. Three replications per genotype per treatment will be used. Briefly, plants will be maintained at 24/16°C (day/night) temperatures and relative humidity of 70% except for the vernalization treatment. The heat treatment will start at the first sign of anthesis. Two temperature regimens of 24/16°C (control) and 34/16°C (Heat stress) will be maintained for 16/8 hour day/light conditions for 10 days before bringing the conditions back to 24/16°C, day/night.The lines with high thermotolerance and high thermosensitivity will be selected for future genetic studies.