The cyst of the soya bean cyst nematode (SCN; Heterodera glycines), an economically important pathogen of soya beans worldwide, represents a unique microhabitat in soil. The fungi inhabiting cysts may include natural antagonists of the SCN as well as saprotrophs and other opportunists. This study aimed to characterise the entire culturable mycobiome of SCN cysts obtained from a long-term soya bean-corn rotation experiment using ITS fungal barcoding. Fusarium was consistently the most frequently isolated taxon across all sampling time points and crop sequences, followed by Ilyonectria. Among fourteen genera frequently isolated from SCN cysts, five fell within the single family Nectriaceae (Sordariomycetes) and five within the order Pleosporales (Dothideomycetes), suggesting independent evolutionary origins and shared adaptations in these groups towards colonisation of SCN cysts. Six genera (Pochonia, Clonostachys, Fusarium, Neonectria, Alternaria, and Leptosphaeria) varied significantly by crop sequence in at least one year.
Bibliographical noteFunding Information:
This research was supported by United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) grant 2015-67013-23419 and the Minnesota Soybean Growers Research and Production Council . The authors acknowledge the contributions of Dr. Yingbo Zhu in culturing fungi, technicians Mr. Wayne Gottschalk, Mrs. Cathy Johnson, Ms. Hannah Neigebauer, and Ms. Yen Vuong and summer interns at the University of Minnesota Southern Research and Outreach Station's nematology laboratory towards maintenance of the long-term rotation, and field sampling and processing. DH thanks Mr. Tae Joon Byun, a graduate student in computer science at the University of Minnesota for helping develop the dhtrim.py program. The authors also acknowledge Mr. Noah Strom, Dr. Rodrigo Olarte and the Kistler Lab for their various inputs and suggestions.
© 2019 The Authors
- Culturable mycobiome
- Fungal community analyses
- Heterodera glycines
- Soybean cyst nematode