A Dihaploid Approach for the Selection of Forage Quality in Tall fescue (Festuca arundinacea Schreb.)

Abstract

Within the Festuca-Lolium genome complex, there is a need for modern breeding approaches that can facilitate the rapid development of improved germplasm or cultivars. Traditional recurrent or mass-selection methods for population or synthetic development are labor intensive and time consuming. The recent development of annual ryegrass Lolium multiflorum Lam.) lines, when hybridized by tall fescue [(Festuca arundinacea Schreb. (syn. = Lolium arundinaceum (Schreb.) Darbysh.)], will produce F1 hybrids, that through mitotic genome loss, lose either their ryegrass or tall fescue genome and result in the recovery of ryegrass and tall fescue dihaploid (DH) lines. For breeding and selection purposes regarding forage quality, the ability to select for superior genotypes at the F1 generation, rather than at the subsequent DH generation would improve the efficiency of the technique. The study examined forage quality components of crude protein (CP), acid digestible fiber (ADF), neutral digestible fiber (NDF) and in vitro dry matter digestibility (IVDMD) expression and inheritance in the F1 and their respective recovered DH lines. Results of the study indicate that forage quality genotypes, conferred by the tall fescue gamete, are heritable and selection performed at the F1 generation will be effective in identifying DH genotypes that are not significantly different in forage quality of their respective F1 parents. Though performed only on CP, ADF, NDF and IVDMD forage quality components, the study suggests similar application toward the selection of additional quantitative forage quality or agronomic attributes for tall fescue improvement. The described selection strategy is applicable to tall fescue (L. arundinaceum) and may have application across the Lolium/Festuca genus.