Characterization, establishment and persistence under grazing of nitrous oxide-induced octoploid Phalaris aquatica L

australia australie chromosome number cultivars establecimiento de plantas grazing grosseur des semences hybride hybrids nitrous oxide nombre chromosomique ovin ovinos oxyde nitreux pastoreo peso de las semillas phalaris phalaris aquatica plant establishment plant habit plantule ploidy poids des semences polen pollen port de la plante productividad productivity seed size seed weight seedlings sheep variedades varieties