Arbuscular mycorrhizae effects on growth of two Hawaiian species: Indigenous Osteomeles anthyllidifolia (Rosaceae) and invasive Psidium cattleianum (Myrtaceae)

摘要

Two important plant species of Hawai'i, the indigenous Osteomeles anthyllidifolia (Sm.) Lindl., a component of Hawai'i's most endangered habitat, and the highly invasive Psidium cattleianum. Sabine were grown with or without arbuscular mycorrhizal fungi in a soilless mix at different soil-solution phosphorus (P) levels. At P levels similar to those in the field (0.007 mg P/liter), shoot biomass of inoculated plants of O. anthyllidifolia was 189 greater than that of controls, and that of P. cattleianum was 93 greater. Root weight of O. anthyllidifolia and leaf-tissue P of both species also were significantly higher in inoculated plants. At a higher concentration of soil-solution P (0.020 mg P/liter), inoculated plants of O. anthyllidifolia had 176 more biomass than controls, and those of P. cattleianum, had 49 more. In a growth medium with soil-solution P equivalent to that of good agricultural soil (0.200 mg P/liter), inoculated plants of O. anthyllidifolia were 101 larger than controls. Results suggest that presence of arbuscular mycorrhizal fungi is of vital importance to establishment of O. anthyllidifolia in Hawaiian soils and that their absence may limit P. cattleianum, invasion of sites that are highly deficient in available P.