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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #391617

Research Project: Identification of Novel Management Strategies for Key Pests and Pathogens of Grapevine with Emphasis on the Xylella Fastidiosa Pathosystem

Location: Crop Diseases, Pests and Genetics Research

Title: Exploring potential induction of grapevine (Vitis spp.) root phenolic compounds by ring nematodes, Mesocriconema xenoplax

item Wallis, Christopher

Submitted to: BMC Research Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2022
Publication Date: 12/21/2022
Citation: Wallis, C.M. 2022. Exploring potential induction of grapevine (Vitis spp.) root phenolic compounds by ring nematodes, Mesocriconema xenoplax. BMC Research Notes. 15:375.

Interpretive Summary: Ring nematodes can greatly impact grapevine yields ultimately resulting in the need to replant vineyards when populations reach critical levels. Management of ring nematodes involves use of resistant rootstocks, but the mechanism of rootstock resistance remains unclear. It was hypothesized that naturally occurring plant compounds called phenolics could impart resistance to ring nematodes, and therefore phenolic levels were quantified in susceptible and resistant grapevine rootstocks both in healthy and ring nematode infested plants. Amounts of phenolics were did not significantly differ between susceptible and resistant rootstocks, were not altered upon nematode infestation, and did not appear to affect nematode survival in bioassays. Therefore, the phenolic compounds analyzed in this study were concluded to not affect ring nematodes, suggesting that other compounds or structures could impart resistance instead.

Technical Abstract: Ring nematodes can decrease grapevine productivity when plated in conditions favorable for their survival. Resistant rootstocks are available to combat harm due to ring nematodes, and compounds called phenolics, including a subclass called stilbenoids, were hypothesized as imparting this resistance. Therefore, this study measured phenolic and stilbenoid compound levels in four different rootstocks and attempted to find associations with ring nematode populations. This study was conducted over two years, 2018 and 2019, and phenolic levels were much greater in 2019 than 2018 likely due to uncontrolled differences in climatic controls. Regardless, within each year resistant rootstock cultivars (‘Schwartzman’ or ‘O39-16’) did not have different phenolic levels than susceptible cultivars (‘St. George’ or ‘Cabernet Sauvignon’). Ring nematode infected grapevines also did not have different phenolic compound levels than healthy controls. Bioassays of different stilbenoid polymers revealed no significant effects on ring nematode survival. These results suggest that analyzed root phenolic compounds were not involved in resistance or susceptibility to ring nematodes.