Pre-competitive facilitated adoption of molecular genetic technologies by pasture plant breeding companies

Summary

The gross economic value of the temperate grazing industries, based on perennial ryegrass pastures, has been estimated at c. $8 billion per annum in Australia. Increases in productivity realised by this industry have the potential to significantly increase the returns to the economy. An adequate rate of genetic gain to the pasture based industries is crucial to generate on-going competitive advantage and industry sustainability. Genetic improvement is designed to increase the profitability of the livestock enterprise through increasing productivity and quality of pasture plants, so that benefits are markedly higher than the costs of additional inputs. The historical rate of progress in the genetic improvement in pasture plant breeding is generally regarded as low, estimates of up to 7% per decade having been made for perennial grasses. Forage plant breeding companies must be provided with the means to deliver both novelty and genetic gain at increased rates.
Molecular marker technology identifies and exploits pre-existing genetic variation in populations to accelerate and re-design breeding programs and is widely used in a variety of agricultural programs, but the complexities of pasture plant breeding has limited its use to date. Practical approaches have been identified and developed to enable incorporation of the molecular breeding technologies within established breeding programs.
From the experimental work performed within the project, extensive analysis using detailed phenotypic and genotypic data has been performed on a clonal ryegrass plant nursery and associated sward trials. This has enabled a collection of novel breeding approaches to be tested and elite crosses to be performed, selecting for improvements in both yield and quality traits. These project activities have demonstrated methods of applying advanced phenotyping and genotyping methods in pasture plant breeding. The project has developed computational tools to assist in cross selection and new advanced phenotyping protocols that, critically, are cost effective for plant breeders, as well as novel cultivar sub-selection approaches that can expedite delivery of advanced products.
The capability for DNA based varietal discrimination and genetic integrity surveillance in pasture grasses has been developed and exemplified through construction of a detailed catalogue of relationships between ryegrass cultivars. This provides a degree of quality assurance and certification that can be deployed in the seed supply chain for ryegrass cultivars today. This outcome will benefit pasture breeding companies, through provision of definition and security of elite cultivars as well as describing the respective relationships between cultivars, which provides knowledge to select genuinely distinct germplasm for breeding programs. The DNA profiling technique will also benefit end-users in the pastoral production industries through increased confidence in dependability of the end-product.
Routine use of robust systems for quality assurance of novel endophyte status of ryegrass seed and tiller material has been implemented within a commercial breeding program. The application of endophyte QA/QC has directly identified levels of contamination in pre-commercial breeding lines for the utilisation partner. Toxic endophyte incursions can cause animal health and welfare issues as well as a loss in productivity. This outcome supports one of the largest suppliers of high-performance ryegrass genetics to the Australian dairy industry to deliver their product with increased confidence for the benefit of the end-user.