Endomycorrhizalinfection Levels among Chenopod Plant Species at Port Wakefield, South Australia

Abstract

The aim of this study was to determine the mycorrhizal colonisation rates among commonly occurring plant species in the family Chenopodiaceae, at Port Wakefield, South Australia. Species in this family are commonly thought to have low or no mycorrhizal colonisation. Mycorrhizal infection in roots of the native chenopod species Sclerolaena obliquicuspis, Enchylaena tomentosa, Rhagodia parabolica and Atriplex stipitata was compared with the commonly mycorrhizal-infected Stipa nitida and Medicago minima. Roots were stained with trypan blue to determine the proportion of root length colonised by arbuscules, vesicles and hyphae. Mycorrhizal structures were found in all species, except Enchylaena tomentosa. Total colonisation rates by mycorrhizae in the chenopod species were low to medium, ranging from 4.25% in Sclerolaena obliquicuspis to 11.6% in Rhagodia parabolica. In comparison, the non-chenopod species Stipa nitida and Medicago minima were highly mycorrhizal. All mycorrhiza-bearing plant species had vesicles and arbuscules present, however the very low rate of arbuscules in the chenopods may indicate that nutrient exchange between the plant roots and mycorrhizal fungi was low.