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National audience ; By a decision of the European Union, the definition of Festulolium was recently extended; the aim of this paper is to direct the attention towards the genetic diversity covered by the new definition and the consequences on the utilisation value of the various cultivars of Festulolium. Recent trial results by GEVES show the genetic differences that exist among the various strains of Festulolium, and also between them and the parental species. They also show their direct influence on the utilisation value of Festulolium. ; Une directive de l'Union Européenne vient d'élargir récemment la définition de Festulolium; l'objet de cette note est d'attirer l'attention sur la diversité génétique que va recouvrir désormais cette nouvelle définition et ses conséquences sur la valeur d'utilisation des variétés de Festulolium. Les résultats d'essais récents du GEVES permettent de bien illustrer les différences d'ordre génétique d'une part entre Festulolium, et vis-à-vis des espèces parentales d'autre part, et comment elles influent directement sur la valeur d'utilisation des Festulolium.

Une directive de l'Union Européenne vient d'élargir récemment la définition de Festulolium; l'objet de cette note est d'attirer l'attention sur la diversité génétique que va recouvrir désormais cette nouvelle définition et ses conséquences sur la valeur d'utilisation des variétés de Festulolium. Les résultats d'essais récents du GEVES permettent de bien illustrer les différences d'ordre génétique d'une part entre Festulolium, et vis-à-vis des espèces parentales d'autre part, et comment elles influent directement sur la valeur d'utilisation des Festulolium. ; By a decision of the European Union, the definition of Festulolium was recently extended; the aim of this paper is to direct the attention towards the genetic diversity covered by the new definition and the consequences on the utilisation value of the various cultivars of Festulolium. Recent trial results by GEVES show the genetic differences that exist among the various strains of Festulolium, and also between them and the parental species. They also show their direct influence on the utilisation value of Festulolium.

Inversion sur la publication des affiliations de T. Bourgoin et J. Hacquet ; Festulolium are interspecific hybrids between Festuca and Lolium species bred to improve forage performances under climate stresses as low and high temperature and water deficit. Thirty-six varieties are presently registered in the European Union list of which, only four are in the French list. The Festulolium definition changed in 2004 in extending potentially to nine amphiploid combinations and more than sixty forms at various degree of introgression, diploid to hexaploid, into four fescue species and three Lolium species including hybrid rye-grass. In this range of continuous variation, the forage performances among Festulolium varieties are still negatively correlated with seed productivity which closely determines availability and benefits for end-users. The project aimed to provide further data on genetic variability of seed productivity and its components as pollen fertility among present varieties and breeding plant material, up to individual plant level to be used as breeding criteria. The results showed that seed productivity is sufficiently restored in Festulolium as soon as they derive from one generation of back-crossing into any tetraploid ryegrass species. By contrast, amphiploid Festulolium whatever they come from, F. pratensis or F. glaucescens, still remained of low seed productivity which germination rate may fail rapidly to meet the 80 % requirement for seed marketing. Remodelling the genome balance in such Festulolium by speeding up interspecific recombination and using molecular tools seem the only mean to increase seed productivity before conventional breeding can take place usefully. To support this considerable long term investment by plant breeders, better identification of genetic structure of candidate Festulolium varieties is required, also defining better adequate tests for VCU. ; Les Festulolium sont des hybrides interspécifiques entre fétuque et ray-grass développés pour améliorer la production fourragère ...

Les Festulolium sont des hybrides interspécifiques entre fétuque et ray-grass développés pour améliorer la production fourragère sous stress climatique, température et déficit hydrique. Il existe à ce jour 36 variétés inscrites au catalogue Européen dont 4 seulement au catalogue Français. Modifiée en 2004, la définition de Festulolium par l'Union Européenne peut recouvrir désormais une très grande diversité de formes ; 9 combinaisons amphiploïdes et plus de 60 formes introgressées à des degrés divers, de 14 à 42 chromosomes, dans 4 espèces de fétuque et 3 espèces de ray-grass dont le ray-grass hybride. Dans ce continuum de variation, le degré d'innovation en matière de performances fourragères reste encore fortement corrélé, et négativement, à la productivité en semences, ce qui conditionne fortement le développement des variétés. Le projet a eu pour objectif d'apporter de nouvelles données de variabilité génétique de la productivité de semences et des composantes de la fertilité, en essai et multiplication, entre variétés et descendances, et jusqu'au niveau de la plante individuelle pour en évaluer l'intérêt comme critère de sélection. Les résultats montrent que la productivité de semences est suffisamment restaurée chez des Festulolium après une seule génération de rétrocroisement dans un ray-grass de niveau tétraploïde, quel qu'il soit. En revanche, les formes amphiploïdes, qu'elles soient issues de F. glaucescens ou de F. pratensis, présentent un net déficit de productivité, aggravé d'une faculté germinative se dégradant rapidement après la récolte. L'amélioration de la productivité semencière doit ainsi constituer un objectif prioritaire chez les Festulolium amphiploïdes pour mieux faire valoir leur potentiel d'innovation dans un contexte de changement climatique. Pour encourager cet investissement de long terme, il est indispensable que la structure génétique des variétés de Festulolium candidates soit mieux identifiée à l'inscription et puisse déterminer des épreuves VATE également mieux ciblées. ; Festulolium are interspecific hybrids between Festuca and Lolium species bred to improve forage performances under climate stresses as low and high temperature and water deficit. Thirty-six varieties are presently registered in the European Union list of which, only four are in the French list. The Festulolium definition changed in 2004 in extending potentially to nine amphiploid combinations and more than sixty forms at various degree of introgression, diploid to hexaploid, into four fescue species and three Lolium species including hybrid rye-grass. In this range of continuous variation, the forage performances among Festulolium varieties are still negatively correlated with seed productivity which closely determines availability and benefits for end-users. The project aimed to provide further data on genetic variability of seed productivity and its components as pollen fertility among present varieties and breeding plant material, up to individual plant level to be used as breeding criteria. The results showed that seed productivity is sufficiently restored in Festulolium as soon as they derive from one generation of back-crossing into any tetraploid ryegrass species. By contrast, amphiploid Festulolium whatever they come from, F. pratensis or F. glaucescens, still remained of low seed productivity which germination rate may fail rapidly to meet the 80 % requirement for seed marketing. Remodelling the genome balance in such Festulolium by speeding up interspecific recombination and using molecular tools seem the only mean to increase seed productivity before conventional breeding can take place usefully. To support this considerable long term investment by plant breeders, better identification of genetic structure of candidate Festulolium varieties is required, also defining better adequate tests for VCU.

Herbage production is regarded as having environment-friendly credentials. However, as the ruminant production it supports is facing major challenges on sustainability, environmental footprint and human health concerns, EU herbage cultivar testing must contribute to the solutions. Before new cultivars can be sold in a member state (MS) and gain EU-wide marketing, they must pass official tests to prove they are both novel (distinct, uniform and stable, DUS) with improved value for cultivation and use (VCU). Herbage species present specific challenges, as their allogamy imposes a wide within-cultivar variation that adds complexity to DUS tests and their "value" is only realized in ruminant produce. Current VCU systems measure production, chemical composition and disease/stress tolerances, often on large numbers of candidate cultivars, but prohibitive labour costs and logistics mean that animal intake, ruminant output or environmental benefits cannot be measured directly. Furthermore, some candidate cultivars with proven superior VCU fail DUS even though the non-distinct comparison is with a significantly lower performing registered cultivar. To resolve these problem cases, a "vmDUS" distinctness tool is proposed, which uses molecular markers but conforms to UPOV-declared principles. A short overview of current grassland research shows smart proxy measures of animal value can easily and quickly be adopted into an integrated pan-European (EU-VCU) test network. The proposed EU-VCU scheme will reallocate test resources to conduct these additional tests by placing MS in data sharing collaborations, while retaining their national listing authority. The benefits to all stakeholders from adopting these new testing procedures are considered.