Arbuscular mycorrhizal fungi and dark septate endophytes in the sugarcane crop cycle: rates and extent of development

SUGARCANE ROOT SYSTEMS host a variety of fungal symbionts including arbuscular mycorrhizal (AM) fungi and dark septate endophytes (DSE). The potential impacts of root-associated fungal symbiosis in sugarcane crops remains poorly understood. A field study was undertaken to assess the colonisation dynamics of AM/DSE in sugarcane sett and adventitious shoot roots from first and second ratoon crops over 28 weeks of development. Significant differences in the rate of sett root colonisation over time were observed between fungal types at both sites. Differences in AM fungal sett root colonisation between sites were not significant. DSE sett root colonisation was significantly lower in the second ratoon compared with the first ratoon crop. For both fungal types, sett root colonisation was significantly higher than for shoot roots at both sites. Maximum colonisation levels of AM/DSE occurred between 5?7 weeks, prior to shoot root establishment and rapid development phase of first and second ratoon crops. These data provide the basis for sampling strategies and further research to assess the impacts of AM/DSE in sugarcane cropping systems.