Festulolium, a century of research and breeding and its increased relevance in meeting the requirements for multifunctional grassland agriculture

Abstract

Festulolium are grasses formed through interspecific hybridisation of ryegrass (Lolium) and fescue (Festuca) species. The Lolium-Festuca genome complex represents a vast array of heterogeneous and largely outbreeding grass species that have evolved, diverged, and adapted, allowing their worldwide colonisation of temperate grasslands. While strategies for grass improvement have focused primarily on intraspecific breeding and, in particular, on the agronomically desirable species Lolium perenne and Lolium multiflorum, a growing interest has emerged in interspecific hybrids as alternatives. The principal driver has been the increased appreciation of the capability of wide hybridisation to extend phenotypic variation beyond the ranges available within a single species. Lolium and Festuca species share complementary and desirable traits, and the prime aim in Festulolium (Festuca × Lolium) cultivar development has been to combine the agronomic performance of Lolium and the stress resistance of Festuca species. Advances in Festulolium development are timely, and support strategies aimed at delivering a more sustainable future for livestock agriculture, with grass cultivars that are persistent and productive. Festulolium hybrids occur naturally, including examples that demonstrate extreme heterosis with adaptations sufficient to sustain growth in harsh conditions. However, they are largely sterile and their perpetuity depends mainly on vegetative propagation. Synthetic Festulolium hybrids suitable for plant breeding require genome stability and fertility, sufficient for a cost-effective seed production. To this end, suitable amphiploid and introgressionbreeding approaches have been developed. Herein, we provide detailed selected highlights in the research and breeding of Festulolium. In addition, recognising the multifunctional properties of grasslands and the development of enabling technologies that permit their study, we review additional benefits likely to accrue from Festulolium that may mitigate climate change effects and provide valuable ecosystem services.

High‐yielding forage grass cultivars increase root biomass and soil organic carbon stocks compared with mixed‐species permanent pasture in temperate soil

“…It is a high‐sugar perennial ryegrass designed for efficient ruminant nutrition (Wilkins & Humphreys, 2003). The Festulolium cultivar Prior, bred at the Welsh Plant Breeding Station in the 1970s, was the first synthetic and commercially‐developed L. perenne × F. pratensis amphiploidy hybrid (Humphreys & Zwierzykowski, 2020). It has inferior agronomic performance compared to AberMagic but greater tolerance to winter stresses and has a deeper root system and root–soil interactions that can enhance soil structure and help mitigate flooding (Li et al, 2017; Macleod et al, 2013).…”

“…As with cereal crops, there have been considerable developments in breeding to produce novel high‐yielding, high‐nutrition forage grass cultivars (Humphreys & Zwierzykowski, 2020). With the focus mainly on the aboveground biomass historically, there has been less attention to belowground biomass and root networks until recently (Marshall et al, 2016).…”

Interspecific hybridization and plant breeding: From historical retrospective through work of Mendel to current crops

“…Fescues, on the other hand, are species with excellent abiotic stress tolerance (Jauhar 1993;Cernoch & Kopecky 2020). To date, almost 100 ×Festulolium cultivars have been released worldwide (Humphreys & Zwierzykowski 2020). Using introgression breeding, various genetic stocks has been released.…”

Festulolium plant yield, nutritive and energy value depending on its variety

“…Festulolium is one of the most resistant and productive species among perennial grasses, especially during the seasons characterized by unfavorable weather conditions. It is a promising crop that meets the high requirements imposed on species being used for creating a high-quality fodder base [1,6,20].…”