Fusarium wilt of cotton may commonly result from the interaction of Fusarium oxysporum f. sp. vasinfectum with Belonolaimus longicaudatus

Authors: DA SILVA, MYCHELE - University Of Georgia; Davis, Richard; DOAN, HUNG - Uc Davis Medical Center; NICHOLS, ROBERT - Cotton, Inc; KEMERAIT, ROBERT - University Of Georgia; HALPERN, HANNAH - University Of Georgia; BREWER, MARIN - University Of Georgia; JAGDALE, GANPATI - University Of Georgia; CHEE, PENG - University Of Georgia

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2018
Publication Date: 5/7/2019
Citation: Da Silva, M., Davis, R.F., Doan, H., Nichols, R., Kemerait, R., Halpern, H., Brewer, M., Jagdale, G., Chee, P. 2019. Fusarium wilt of cotton may commonly result from the interaction of Fusarium oxysporum f. sp. vasinfectum with Belonolaimus longicaudatus. Journal of Nematology. 51:10. https://doi.org/10.21307/jofnem-2019-015.
DOI: https://doi.org/10.21307/jofnem-2019-015

Interpretive Summary: The interaction between Fusarium oxysporum f.sp. vasinfectum (Fov) and Meloidogyne incognita (cotton root-knot nematode) resulting in Fusarium wilt (FW) of cotton is well known. Although Belonolaimus longicaudatus (sting nematode) can interact with Fov and cause FW, it has long been believed that virtually all of the FW in Georgia is caused by the interaction of Fov with M. incognita. In recent years, FW has been reported more frequently in Georgia, which suggests that something affecting the disease complex may have changed. In 2015 and 2016, a survey of 27 Georgia cotton fields in 10 counties was conducted. At least 10 soil and stem samples per field were collected from individual plants showing symptoms of FW to quantify plant parasitic nematode levels and to identify Fov races based on genetic differences. Fov race 1 was identified in all samples in 2015, but one sample also had the LA 110 genotype and another sample also had the LA 108 genotype. In 2016, all Fov races and genotypes found in 2015 were present, however, MDS-12 and LA127/140 also were found. The cotton root-knot nematode was present in 18% of fields in 2015 and 40% in 2016, but the sting nematode was present in all fields in 2015 and 75% of fields in 2016. Root-knot and sting nematodes were present, respectively, in 18% and 55% of the samples in 2015 and 40% and 51% in 2016. However, root-knot nematode without sting nematode was found in 7% of samples in 2015 and 34% of samples in 2016, whereas sting nematode without root-knot nematode was found in 45% of samples in 2015 and 44% of samples in 2016. We conclude that 1) Fov race 1 continues to be the dominant race in Georgia, and 2) many instances of Fusarium wilt in Georgia may be due to Fov interacting with sting nematode and not root-knot nematode as previously believed.

Technical Abstract: The interaction between Fusarium oxysporum f.sp. vasinfectum (Fov) and Meloidogyne incognita (root-knot nematode) resulting in Fusarium wilt (FW) of cotton is well known. Although Belonolaimus longicaudatus (sting nematode) can interact with Fov and cause FW, it has long been believed that virtually all of the FW in Georgia is caused by the interaction of Fov with M. incognita. In recent years, FW has been reported more frequently in Georgia, which suggests that something affecting the disease complex may have changed. In 2015 and 2016, a survey of 27 Georgia cotton fields in 10 counties was conducted. At least 10 soil and stem samples per field were collected from individual plants showing symptoms of FW to quantify plant parasitic nematode levels and identify Fov races. Fov race 1 was identified in all samples in 2015, but one sample also had the LA 110 genotype and another sample also had the LA 108 genotype. In 2016, all Fov races and genotypes found in 2015 were present, however, MDS-12 and LA127/140 also were found. Meloidogyne incognita was present in 18% of fields in 2015 and 40% in 2016, and B. longicaudatus was present in all fields in 2015 and 75% of fields in 2016. Meloidogyne incognita and B. longicaudatus were present, respectively, in 18% and 55% of the samples in 2015 and 40% and 51% in 2016. However, M. incognita without B. longicaudatus was found in 7% of samples in 2015 and 34% in 2016, whereas B. longicaudatus without M. incognita was found in 45% of samples in 2015 and 44% in 2016. We conclude that 1) Fov race 1 continues to be the dominant race in Georgia, and 2) many instances of Fusarium wilt in Georgia may be due to Fov interacting with B. longicaudatus and not M. incognita as previously believed.