Rapid detection of arbuscular mycorrhizae in roots and soil of an intensively managed turfgrass system by PCR amplification of small subunit rDNA

Arbuscular mycorrhizal fungi (AMF) were detected in uninoculated soil and roots of turfgrass (Agrostis palustris) by direct extraction and PCR amplification of the small subunit rRNA gene. Sequence analysis of the cloned PCR product confirmed the identity of the amplified DNA as an AMF sequence having 95% identity to Glomus intraradices. The sensitivity of the method was gauged by comparison with the most probable number analysis of infective propagules in an intensively managed turfgrass system having 56 propagules per 100 g soil. In contrast to the heavily managed system, infective propagule numbers were high in systems under moderate and limited management. The method described may be useful for rapid investigations of genetic diversity and community structure of AMF.