Evaluation of Catenaria anguillulae and its potential use as a biological control agent of Meloidogyne incognita, Heterodera glycines, and Rotylenchulus reniformis

Abstract

The overall objectives of this study are 1) to isolate Catenaria sp. from nematode samples, grow them in pure culture, and determine the best culture media and incubation temperatures; 2) identify species of Catenaria found through morphological and molecular techniques; 3) test pathogenicity of Catenaria sp. on Rotylenchulus reniformis, Meloidogyne incognita, and Heterodera glycines in vitro to determine biological control potential; 4) evaluate biological control potential of isolated Catenaria sp. in greenhouse, microplot, and field settings. Catenaria sp. was isolated from R. reniformis and H. glycines and increased on 0.4% beef extract agar (BEA) plates. Sequencing of the internal transcribed spacer (ITS1) and ITS4 regions of Catenaria sp. DNA indicated that isolates of Catenaria sp. obtained from both H. glycines and R. reniformis shared a 95% identity with C. anguillulae. Growth tests were conducted on five different medium and BEA was the only media tested that supported growth of C. anguillulae. Six incubation temperatures ranging from 10-40°C indicated that C. anguillulae grew at temperatures of 20-35°C. In vitro testing found that C. anguillulae has the ability to infect all three nematode species tested with highest infection rates occurring on heat-killed M. incognita J2. In greenhouse testing, C. anguillulae lowered H. glycines cyst numbers by an average of 45.6%. Meloidogyne incognita population density was reduced when treated with heat-killed M. incognita J2 that were colonized by C. anguillulae in microplot testing. Field tests with C. anguillulae found no reduction in nematode population density at 45 days after planting under the condition used in the testing.