BBSRC Core Strategic Programme in Resilient Crops: Grasslands Gogerddan

Genetics of field persistence of perennial forage grasses and white clover: we will develop genetically defined experimental populations of ryegrass and clover grown as: a) single and multi-population swards and, b) spaced plants in the field. We will determine allelic profiles of sward populations following sowing, establishment and subsequent sward development, using genotyping by sequencing (GBS), and measures of forage quality and phenology. Data will be collected over multiple years and across different environments. Based on sward and spaced plant data, selected genotypes will be phenotyped in the NPPC. We will compare significant shifts in allele frequencies within the swards with the location of QTL for performance and quality traits identified in mapping families and NPPC data. By integrating across scales, we will use NPPC and spaced plant phenotypes to test predictions of field performance of related populations.
2. Plant architecture and genetics of field persistence in red clover: red clover is a high protein forage legume with many benefits in crop rotation, but it is not very persistent, particularly under grazing. This is most likely associated with plant architecture, including erect versus prostrate growth habit, dependency on the crown for regrowth and ability to develop roots from nodes of creeping stems. Previous BBSRC work has allowed us to develop a Pseudo NAM population which segregates for growth habit and architecture. Field experiments are still in progress, but large differences can be observed between progeny, indicating a substantial genetic element to these traits. We will use an F2 family from the Pseudo NAM population to compare with parental populations, accessions with prostrate and erect growth habit in field experiments. We will obtain data on allele frequency changes over years in the swards, and associate this with phenotypic data of plant growth habit, forage quality and phenology. This will allow us to locate QTL and further fine mapping of the traits. The genomic and phenotypic data obtained from both red clover and the ryegrass-white clover experiments in this project will also be used to develop predictive models for field performance.
3. Abiotic stress – soil water status: in the UK, the length, seasonal timing and year-to-year variations in soil water status are unpredictable but have major implications for grassland productivity and management. This means that permanent grasslands must have the capacity to withstand periods of both water-logging and drought. We will undertake a genetic and transcriptomic study of ryegrass responses to both extremes of soil water status. We will initially evaluate a panel of genotypes in glasshouse drought-bin and water logging experiments for growth during and recovery after stress conditions. We will also develop genetic mapping families for QTL analysis and complementary RNA-seq data sets to identify differentially expressed genes and associated gene-networks. Through genome anchoring, we will relate differentially expressed gene and QTL positions to allelic shifts identified in field-based sward experiments. This will identify targets for gene validation through gene expression and editing technologies.
4. Enabling science and technologies for enhancing forage quality: forage quality is a product of genotype x environment interactions and is a key component of forage environmental impact and economic viability. We will define and evaluate key components of forage quality both in terms of field performance and their potential for influencing animal production and well-being. This will include characterising and manipulating the genetics of forage quality and developing molecular tools for the validation and manipulation of key genes in forage quality pathways.