Reproduction of Heterodera glycines on Soybean in Nonsterile Soil Infested with Cyst-Colonizing Fungi


  • C. M. Stiles
  • D. A. Glawe
  • G. R. Noel
  • J. K. Pataky


Biological Control, Diheterospora chlamydosporia, Fusarium oxysporum, Fusarium solani, Glycine max, Heterodera glycines, Paraphoma radicina, Pyrenochaeta terrestris, Soybean, Stagonospora heteroderae


Six fungi capable of colonizing roots of soybean were isolated from cysts of Heterodera glycines recovered from field soil suppressive to the nematode. The fungi were evaluated for the ability to reduce reproduction of first-generation H. glycines under greenhouse conditions. Diheterospora chlamydosporia (Synonym: Verticillium chlamydosporium), Fusarium oxysporum, F. solani, Paraphoma radicina, Pyrenochaeta terrestris, and Stagonospora heteroderae were inoculated separately onto roots of 3- and 10-day-old 'Williams 82' soybean seedlings that were transplanted into nonsterile soil free of H. glycines. Second-stage juveniles (J2) of H. glycines were added 3 days after inoculating with fungi and numbers of first-generation cysts, eggs, and J2 were determined. The fungi did not reduce either the number of cysts or the total number of eggs and juveniles. Inoculation of roots with F oxysporum resulted in a significant (P = 0.10) increase in numbers of cysts and of eggs and juveniles when c