Breeding Strategies to Improve Miscanthus as a Sustainable Source of Biomass for Bioenergy and Biorenewable Products

Abstract

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.

The Impact of Soil Water Content on Yield, Composition, Energy, and Water Indicators of the Bioenergy Grass Saccharum spontaneum ssp. aegyptiacum under Three-Growing Seasons

“…It is imperative that agriculture will take these threats as opportunities, by diversifying crop options, introducing new cropping systems with locally adapted genotypes combined with sustainable agronomic practices to provide raw material for the bioeconomy and to conserve natural resources [38]. Advanced research on locally adapted plants, aimed at identifying stress-resilient traits and to breed resource-efficient and climate-resilient genotypes, will likely play a key role in strength synergies among farmers, practitioners, and industries to optimize bioeconomy value chains [39][40][41][42][43][44].…”

Physiological Response of Miscanthus x giganteus to Plant Growth Regulators in Nutritionally Poor Soil

“…Thus, any currently available variant is not ideal. For the future, a very promising solution is the development of new hybrids which are more stress tolerant and provide higher biomass yields in marginal soils compared to currently used genotypes [17,68].…”

Wild Miscanthus Germplasm in a Drought-Affected Area: Physiology and Agronomy Appraisals

“…Despite the large genetic diversity of this genus, the most widely used Miscanthus for biomass production is M. x giganteus, a naturally occurring triploid hybrid [7,13,14]. M. x giganteus is sterile therefore commercial expansion is limited by low multiplication rates from clonal propagation, high establishment costs and patchiness associated with rhizome propagation [15,16]. Furthermore, the physiology of M. x giganteus is not well suited to areas with limited water supply and extreme summer drought, such as the southern Mediterranean [17,18].…”

“…Natural diversity in physiological, morphological and compositional traits is important for breeding improved, high-yielding and locally adapted varieties that are resilient to climate change and extreme weather events [16]. A replicated spaced plant trial in the UK, containing 244 genotypes of the three species demonstrated large variations in canopy height, stem density, flowering time, leaf senescence rate and biomass yield [19].…”