Vesicular- Arbuscular Mycorrhizae of Some Hawaiian Dune Plants

Abstract

The mycorrhizal status of dune plants from the island of Hawaii was investigated. All plants, including Batis maritima, Cocos nucifer, Ipomoea brasiliensis, Pennisetum setaceum , Prosopis pallida, Scaevola taccada, and Sporobolus sp., had vesicular - urbuscular mycorrhizae (VAM). Levels of colonization by VAM fungi ranged from less than 10% to 100% of the root length and were highest in Ipomoea , Pennisetum, and Sporobolus. Twelve species of VAM fungi were recovered, half of which are undescribed. The most frequently recovered species were Sclerocystis sinuosa, Glomus microaggregatum, an undescribed Glomus sp., and an undescribed Scutellospora (Gigaspora) sp. The composition of the VAM fungal communities of the black sand dunes differed from those of the quartz and carbonate dunes. The community of Hawaiian dune mycorrhizal fungi was very distinct from dune communities of Australia, San Miguel Island (California), the Atlantic Coast of the United States, Scotland, and Italy. The presence or absence of VAM fungi in dunes may have been of critical importance to the successful colonization of the Hawaiian Islands by some vascular plants, and these fungi may thus have influenced the subsequent development of the native flora.