ForageTILLING - Forward Genetics in perennial ryegrass

Contact person: Steven Yates

Partners: Michelle Nay, Chloé Manzanares-Yates and Bruno Studer

Project description: In this study, through a forward genetic screen, we aim at finding beneficial alleles to increase abiotic stress tolerance in perennial ryegrass. This project bridges the gap between many projects in the FCG. This work has taken advantage of the ongoing TILLING project, which uses a reverse genetics approach. Here we are using mutagenised seed and multiple stressor compounds to screen high number of seed (~ 20,000 seed per stressor) to identify genotypes which are resistant under extreme abiotic stress.

We screened chemically mutagenised perennial ryegrass seeds in the M1 generation for tolerance to salt, water stress and the stress signaling phytohormone abscisic acid (ABA). Through screening more than 100,000 seeds, we have identified 49 salt mutants, 22 osmotic stress mutants and 16 ABA mutants. Tolerant phenotypes could be distinguished from normal phenotypes through germination or enhanced root growth on media containing the stressor. Confirmative tests to validate the stress resistant phenotypes were performed with plants from the salt screen and have indicated enhanced salt tolerance of five mutants and two wild type plants.

To our knowledge, this is the first time this has been reported in perennial ryegrass. Moreover we demonstrate the use of three different stressors, and the established screening approach could be extended to other stressors or genotypes with different backgrounds. The mutants found here show promise for future study in fundamental and applied research. These plants are currently being propagated for future study and crossing to produce M2 generation.