(Photograph = Fungal Cultures, David Midgley)

Introduction

Fungi associate with essentially all plants. Fungi cover the roots of plants and are on the surfaces of stems and leaves. Fungi even grow inside plants. Fungi inside of plants are called endophytes (endo = inside). Because the plants often grow normally, it is presumed/possible that the fungi growing inside the plants generally cause no harm or may even help the plants.

The Details

Scientists studied 21 cactus species in Arizona for the presence of endophytes. The studied cacti included multiple representatives of Opuntia, Cylindropuntia, Echinocereus, Mammillaria. Also a Consolea species and Cargegiea gigantea were examined.

Up to seven species of fungi were found inside of Cylindropuntia fulgida, which might be high for cacti but which is a low number for tropical plants. Tropical plants from rainy areas may have 20 or more species of fungi inside of them.

The fungi included:

• Phoma
• Aureobasidium
• Alternaria
• Fusarium
• Ascochyta
• Chaetomium

The scientists did not find Colletotrichum, Phomopsis, or Phyllosticta, which have been reported in tropical plants. Overall, while many fungi were found in the desert cacti, the scientists concluded that the diversity was relatively low compared to that of tropical plants.

Additional Reading: Endophytic Fungi Associated with Cacti in Arizona