Study of Two Fungus-Eating Worms Affecting Strawberry Plants

Jim Crocker
8th July, 2024

Study of Two Fungus-Eating Worms Affecting Strawberry Plants

Microscopic images confirm the facultative plant-parasitic ability of Aphelenchoides bicaudatus by showing it tunneling inside soybean leaf tissue (a), with its identity confirmed by its characteristic bifurcate tail (b) and stylet (c).

Image adapted from: Oliveira et al. / CC BY (Source)

Key Findings

  • The University of Florida study (2016-2021) found various nematode species in Florida strawberry fields
  • A. bicaudatus and A. rutgersi were found on desiccated leaves, not harming healthy strawberry plants
  • Managing fungal infections in strawberry fields could help control nematode populations
Nematodes, tiny worm-like organisms, play a significant role in the health of plants, often acting as both pests and beneficial organisms. A recent study conducted by the University of Florida from 2016 to 2021 has shed light on the presence and behavior of various nematode species in Florida strawberry fields[1]. This research is crucial as it helps us understand the interactions between nematodes and plants, potentially leading to better agricultural practices and plant health management. The study found several species of foliar nematodes (Aphelenchoides spp.) in Florida strawberry fields. Notably, Aphelenchoides besseyi sensu stricto was detected only in 2016 and 2017 on healthy strawberry leaves and buds. However, other lesser-known populations of Aphelenchoides sp. were found on declining and desiccated leaves. These samples were identified as A. bicaudatus and A. rutgersi through morphological and molecular analyses. This marked the first detection of A. bicaudatus in Florida, while A. rutgersi had been previously reported in the citrus rhizosphere in the region. The nematodes differed in the shape of their tail terminus, which is a distinctive feature used for identification: A. bicaudatus had a bifurcate tail, A. rutgersi had a mucronate tail with a ventral thin mucro, and A. besseyi had a stellate tail. Phylogenetic analyses of the rRNA gene sequences revealed that the Florida populations of A. bicaudatus were closely related to those from South Korea, Taiwan, and the Netherlands, as well as other populations from Brazil, Costa Rica, and Japan. Similarly, Florida A. rutgersi grouped with samples from Japan and North Carolina. Interestingly, photosynthetic strawberry leaf samples were free from both A. bicaudatus and A. rutgersi, indicating that these nematodes did not damage the strawberry plants. Instead, they were associated with desiccated leaves and propagative stolons, usually infected by fungi, confirming their mycetophagous (fungus-feeding) nature under field conditions. The study also explored the potential for A. bicaudatus to become phytophagous (plant-feeding) under artificial conditions. When soybean leaves were inoculated with A. bicaudatus specimens on moist filter paper, the nematodes penetrated the leaf epidermis, causing localized tissue discoloration and necrosis. However, the damage was minimal, and no nematode reproduction was observed in the inoculated areas. These findings align with earlier studies that have highlighted the complex interactions between nematodes, plants, and fungi. For instance, A. bicaudatus has been previously identified in planting materials and water samples from floral ornamental nurseries in Taiwan, where it established in various hosts without causing immediate symptoms[2]. Additionally, A. besseyi and A. pseudogoodeyi, foliar nematodes associated with commercial strawberry production in Florida, have shown varying reproductive and feeding habits on different fungi, indicating that fungi play a crucial role in maintaining soil-dwelling populations of these nematode species[3]. The University of Florida study expands on these findings by providing new insights into the behavior and distribution of A. bicaudatus and A. rutgersi in strawberry fields. By confirming that these nematodes are primarily mycetophagous and not harmful to healthy strawberry plants, the research suggests that managing fungal infections in strawberry fields could be an effective strategy to control nematode populations. This approach aligns with recommendations from earlier studies, which advocate for the removal of fungus-infected plant residues to limit nematode populations[3]. Overall, this research enhances our understanding of nematode-plant-fungi interactions and offers practical solutions for managing nematode populations in agricultural settings. By focusing on the ecological roles of nematodes and their relationships with fungi, growers can develop more sustainable and effective plant health management practices.

BiochemPlant ScienceMycology

References

Main Study

1) Morphological and Molecular Analysis of Two Mycophagous Nematodes, Aphelenchoides bicaudatus and A. rutgersi (Nematoda: Aphelenchoididae) from Florida Strawberry.

Published 8th July, 2024

https://doi.org/10.2478/jofnem-2024-0021

Related Studies

2) Aphelenchoides bicaudatus from Ornamental Nurseries in Taiwan and Its Relationship with Some Agricultural Crops.

https://doi.org/10.1094/PDIS-03-12-0229-RE

3) Feeding Selectivity of Aphelenchoides besseyi and A. pseudogoodeyi on Fungi Associated with Florida Strawberry.

https://doi.org/10.1094/PDIS-11-21-2463-RE


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