A comparative study of aluminium and nutrient concentrations in mistletoes on aluminium‐accumulating and non‐accumulating hosts

Mistletoes offer a unique model to study interactions among A l and nutrients in vascular plants, because they grow and reproduce on hosts with distinct A l uptake strategies. We investigated A l distribution and nutrient relations of mistletoes on A l‐accumulating and non‐accumulating hosts. We hypothesised that mistletoes would exhibit similar leaf nutrient and Al concentrations as their host plants, but a strong compartmentalisation of A l when growing on A l‐accumulators. We measured concentrations of N , P , K , C a, M g, C u, F e, M n, Z n in leaves and A l in leaves, seeds and branches of P hthirusa ovata and P sittacanthus robustus infecting M iconia albicans, an Al‐accumulator, and P h. ovata infecting B yrsonima verbascifolia , a non‐ A l‐accumulator. High leaf concentrations of Al in P h. ovata only occurred while parasitizing the A l‐accumulating host; there was no accumulation in branches or seeds. In P . robustus , large concentrations of A l were found in leaves, branches and seeds. Mistletoe seed viability and leaf nutrient concentrations were not affected by A l accumulation. Passive uptake of A l, C a, M g, M n and C u in mistletoes was evidenced by significant correlations between mistletoes and host leaf concentrations, but not of N , P and K . A l was retranslocated to different plant organs in P . robustus , whereas it was mostly restricted to leaves in P h. ovata . We suggest that Al might have some specific function in P . robustus , which only parasitizes Al‐accumulator hosts, while the host generalist P h. ovata can be considered a facultative A l‐accumulator.