LAUSR

ABSTRACT New breeding lines of Phalaris (Phalaris aquatica), cocksfoot (Dactylis glomerata) and tall fescue (Festuca arundinacea = syn. Lolium arundinaceum) are currently under evaluation for the selection of new cultivars for low rainfall environments. The aim was to test the relative tolerance of six elite genotypes of Phalaris, cocksfoot and tall fescue to aluminium and manganese toxicities in solution culture. Two solution culture experiments were conducted at aluminium concentrations of 0, 50, 100, 200 and 300 µM, or manganese (Mn) concentrations of 0, 2, 4, 6 and 8 mM in a basal nutrient solution at pH 4.5. Elite genotypes of cocksfoot, AVH48 Selection and Moroccan Fine, exist with improved tolerance to aluminium and Mn toxicities. Elite genotypes of Phalaris, particularly Northern Retainer, were superior to Sirolan at moderate to high aluminium concentrations in solution. There was little difference in the tolerance to aluminium and manganese toxicities between the elite genotypes and existing cultivars of tall fescue.