Arbuscular mycorrhiza in species of Commelinidae (Liliopsida) in the state of Pernambuco (Brazil)

Abstract

Mycorrhiza are a mutualistic symbiosis between fungi and plant roots, the main benefit to the plant being increased nutrient uptake. The arbuscular is the most important kind of mycorrhiza for agriculture and it is widespread in occurrence and distribution in most ecosystems. The aim of this work was to study the mycorrhizal status of the species of Commelinidae that occur in the State of Pernambuco. Plant roots, collected in ten municipalities, were washed, cleared in KOH, stained with Trypan blue in lactoglycerol and observed under a light microscope in order to assess presence and identification of the mycorrhizal type. Percentage of root colonization was evaluated by the gridline intersect method. Forty specimens representing 30 species were observed. From these specimens, 70% were colonized by arbuscular mycorrhizal fungi (AMF). In one family (Typhaceae), mycorrhizal structures were not observed, in two of them (Eriocaulaceae and Juncaceae) all specimens showed the association, and three families (Commelinaceae, Cyperaceae and Poaceae) presented specimens with or without AMF. In some of the roots, other fungi were observed together with the AMF. The results indicate that AMF are widely distributed among species of Commelinidae in Pernambuco, being probably important for their establishment in the areas visited.

Keywords

• Cyperaceae
• Eriocaulaceae
• Poaceae
• mycorrhizal fungi
• symbiosis