We examined colonisation of subterranean clover by arbuscular mycorrhizal fungi.
Colonisation was 12–68% of root length across 137 lines representing the species.
Differences in colonisation between two cultivars were consistent across 11 soils.
Key root traits for phosphorus-uptake changed little when the fungi were present.
Potential may exist to develop cultivars with differing mycorrhizal colonisation.