bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.09.04.674243

Balancing disease control efficacy, resistance durability, and economic outcomes: Insights from a participatory modeling study integrating grapevine cultivar deployment timing with fungicide treatments

Zaffaroni, M.·Alonso Ugaglia, A.·Miclot, A.-S.·Rimbaud, L.·Papaix, J.·Rey, J.-F.·Fabre, F.
View original source ↗Export metadata ↓

Abstract

1In this study, we developed, assessed and compared strategies for deploying disease-resistant grapevine cultivars in partnership with a wine cooperative in South-West France. In four collaborative workshops, cooperative managers and multidisciplinary researchers jointly designed six feasible deployment strategies. These scenarios, implemented within real vineyards, involve planting resistant cultivars (RC) in vineyards (i) more than 30 years old, (ii) on 3.3% of the older plots each year or (iii) on plots located in no-treatment zone (due to proximity to watercourses or human dwellings), with and without a fixed maximum percentage of resistant cultivars in the vineyard. The strategies were evaluated with the landsepi model, which simulates the spread and evolution of pathogens across agricultural landscapes in response to host resistance deployment. The assessment criteria included downy mildew control efficacy, resistance durability, decrease in fungicide use, and economic benefits for individual vineyards and the cooperative. These scenarios led us to study more specifically the effects of two little-studied factors: (i) the presence or absence of fungicide applications and (ii) the massive or progressive introduction of resistant cultivars. Fungicide application substantially decreases the risk of resistance breakdown and complements the epidemiological control provided by resistant cultivars, particularly when the fitness costs of virulence are low. The probability of pathogens adapted to RC becoming established was generally lower with progressive than massive RC introduction; however, when establishment did occur, the time to establishment was shorter for progressive strategies at a cropping ratio [≥] 50%. Ultimately, the choice of RC introduction strategy had a minimal overall impact on disease control due to compensatory epidemiological and evolutionary processes, including dilution effects, and the probability and timing of resistance breakdown. These results are discussed in the broader framework of action-research approaches and the challenges and opportunities for resistant cultivar adoption by vine-growers. Our study highlights the potential of participatory approaches for developing practical, scientifically grounded strategies for sustainable viticulture.

Explore related subjects

evolutionary biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Zaffaroni, M., Alonso Ugaglia, A., Miclot, A.-S., Rimbaud, L., Papaix, J., Rey, J.-F., Fabre, F.. 2025-09-08. Balancing disease control efficacy, resistance durability, and economic outcomes: Insights from a participatory modeling study integrating grapevine cultivar deployment timing with fungicide treatments. https://doi.org/10.1101/2025.09.04.674243

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

RELAX does not reproduce its own estimates at default settings, and its output does not show it

Selection-intensity estimates from RELAX are reported as a point value of K with a likelihood-ratio P. We report that, at default settings and on data of ordinary size, the program does not reproduce its own fits. Of 27 enzyme entries refitted under two optimiser configurations, none reproduced its log-likelihood to within 0.01 units; the median change was 103 units, the largest over 3,400, and four verdicts reversed. Eighty null orthologues reproduced none. A byte-identical command returned a distinct likelihood on every repetition, single-threaded, across three releases, and on alignments simulated under the fitted model, where 3.3 per cent of replicates reproduced. The documented random-number seed never reaches the generator when assigned on the command line, yet reads back as the value supplied. PAML localises the cause: its two-ratio model, without site classes, reproduced its log-likelihood for all 288 genes; its site-class models agreed for 27 to 67 per cent. The instability follows the mixture over sites, not the program. The output does not show it: 46 of 410 fits ended with a negative likelihood-ratio statistic, impossible under convergence, and 123 of 410 report a K re-estimated under a domain restriction rather than the unconstrained maximum. Of 234 published studies using RELAX, none reported a seed. Seeding while holding the thread count at one reproduced sixty of sixty runs on twenty genes under two releases; the seed alone reproduced none of five, and no documentation states the second condition. We recommend that fits be repeated and their dispersion published.

evolutionary biology↗
bioRxiv2026

Sequential accumulation of adaptive alleles forms an inversion supergene in deer mice

Supergenes are clusters of co-inherited loci that affect multiple or complex phenotypes. Despite the growing number of chromosomal inversions identified as supergenes in natural populations, their molecular basis and evolutionary history often remain obscure. Here, we identified two candidate genes, Slc45a2 and Npr3, within a 41-Mb inversion supergene in the deer mouse (Peromyscus maniculatus) that respectively drive darker coats and longer tails - two traits associated with forest adaptation. Mice homozygous for the inversion (inv/inv) exhibit elevated Slc45a2 expression in melanocytes relative to the congenic standard genotype (std/std), disrupting pheomelanin production. In parallel, downregulation of Npr3 in inv/inv mouse growth plates prolongs postnatal growth of caudal vertebrae, resulting in tail elongation. Population-level analyses further implicate that this supergene arose through the subsequent accumulation of the Npr3 allele within the inversion, rather than by capturing all beneficial mutations at its origin.

evolutionary biology↗
bioRxiv2026

Toxin structure shapes palatability in a chemically defended butterfly

The toxicity of chemical defences is well studied, but the potential contribution of compound structure to predator deterrence remains largely unexplored. Whether predation acts more strongly on toxicity or unpalatability remains largely untested, partly because few systems allow toxin structure to vary independently of quantity. Heliconius sara larvae provide such a system: those reared on Passiflora auriculata sequester cyclopentenyl cyanogenic glucosides (CGs), while those reared on P. biflora biosynthesise comparable quantities of aliphatic CGs. Using two invertebrate predators, Camponotus floridanus ants and Hierodula membranacea mantids, we tested whether this structural difference affects palatability independent of toxicity. Mantids rejected larvae with cyclopentenyl CGs more often than larvae with aliphatic CGs, despite no detectable difference in total CG content. This pattern was mirrored in extract-based assays with ants, independently of cyanide release: extracts with cyclopentenyl CGs remained deterrent, while extracts with aliphatic CGs did not differ in deterrence from water. Live larvae, by contrast, elicited similar responses from ants regardless of CG structure. These results show that variation in toxin structure can strongly affect palatability, with some compounds conferring greater protection than others. This demonstrates the importance of chemical structural diversity in the evolution of chemical defences.

evolutionary biology↗