Feeding selectivity of Aphelenchoides besseyi and A. pseudogoodeyi on fungi associated with Florida strawberry

Authors: OLIVEIRA, CLEMEN - University Of Florida; Schumacher, Lesley; PERES, NATALIA - University Of Florida; BRITO, JANETE - Florida Department Of Agriculture; SUAREZ, MARCO - University Of Florida; DESAEGER, JOHAN - University Of Florida

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2021
Publication Date: 6/13/2022
Citation: Oliveira, C.J., Schumacher, L.A., Peres, N.A., Brito, J.A., Suarez, M., Desaeger, J. 2022. Feeding selectivity of Aphelenchoides besseyi and A. pseudogoodeyi on fungi associated with Florida strawberry. Plant Disease. 1-6. https://doi.org/10.1094/PDIS-11-21-2463-RE.
DOI: https://doi.org/10.1094/PDIS-11-21-2463-RE

Interpretive Summary: Foliar nematodes are fungal feeders that can also damage many agricultural crops as they feed on aboveground plant parts. There is a lack of information on their biology and how to successfully allow them to reproduce under laboratory conditions. There is a concern that foliar nematodes are threatening strawberry production in Florida. The objective of this work was to assess the best fungi species that can serve as a food source for foliar nematodes. Two species of foliar nematodes were inoculated onto plates containing the major Florida strawberry fungal pathogens along with non-strawberry-pathogenic fungi. We found that the nematode species that caused damage to strawberry prefers only strawberry fungal pathogens whereas the other nematode species was not selective in its feeding habits. Information from this study will help scientists to foster reproduction and maintenance of foliar nematodes under laboratory conditions. This work suggests that removal of plant residue infected by strawberry fungal pathogens is a desirable and effective management tool for reducing populations densities of foliar nematodes.

Technical Abstract: Aphelenchoides besseyi and A. pseudogoodeyi are foliar nematodes associated with commercial strawberry production in Florida, USA. The reproductive and feeding habits of these two nematode species were assessed on Florida isolates of the fungi Botrytis cinerea, Colletotrichum gloeosporioides, Macrophomina phaseolina, and Neopestalotiopsis spp. pathogenic to strawberry, and the non-pathogenic isolates of Fusarium oxysporum and Monilinia fructicola grown on PDA in petri dishes. Each culture was inoculated with six specimens with mix life stages of either A. besseyi and A. pseudogoodeyi and incubated at 24°C under axenic and non-axenic conditions 23 and 31 days after inoculation, respectively. Aphelenchoides besseyi reproduction rates were significantly higher on strawberry pathogenic isolates of B. cinerea, C. gloeosporioides, and Neopestalotiopsis rosae than on the non-pathogenic isolates of F. oxysporum and M. fructicola. In contrast, reproductive rates of A. pseudogoodeyi did not significantly vary across the fungi cultures. For both nematode species, Macrophomina phaseolina was a poor host because it did not produce mycelium on the media used. Our findings indicate that A. besseyi is more selective in its fungal-feeding preference than A. pseudogoodeyi. Additionally, A. pseudogoodeyi eggs and juveniles were significantly higher than adults. Yet, for A. besseyi, adult stages were more common. Fungi aid in the maintenance of soil-dwelling populations of these two nematode species. Removing fungi-infected strawberry plant residues is both a desirable and effective management practice to limit A. besseyi in central Florida commercial strawberry fields.