Disease influences host population growth rates in a natural wild plant–pathogen association over a 30‐year period

Abstract

1. The epidemiological and demographic dynamics of plant-pathogen interactions in natural environments are strongly affected by spatial and temporal influences.Here we assess the interaction between Filipendula ulmaria and its rust pathogen Triphragmium ulmariae by analysing a 30-year long dataset that has followed pathogen and plant population dynamics in a metapopulation of ~230 host patches growing on islands of the Skeppsvik archipelago in northern Sweden.2. Over this period, the host metapopulation initially expanded in both number and size of individual patches before plateauing. In contrast, the pathogen metapopulation showed greater change. Disease incidence showed a convex pattern rising for the first decade before showing a marked decline in the last decade. At the same time, the prevalence of disease in infected populations showed a constant 30-year long decline.3. At the individual host population level, each population was annually classified into one of four inter-year states: healthy, recolonization, extinction and diseased.Host populations that were healthy from 1 year to the next were significantly smaller than all other host population categories, while host populations in which disease was constantly present were significantly larger. 4. Host populations in which the pathogen underwent either an extinction or a recolonization event were of similar size and represented a measure of the host threshold size for long-term pathogen survival.5. Host population growth rates declined as disease levels increased. The growth rate of host populations in which disease was continuously present was 75% lower than in populations that were free disease.6. The sensitivity of the association to climate change as demonstrated through a decline in disease incidence and prevalence and an increase in drought damage to plant populations as temperatures rise has only become apparent through analysis of an extensive long-term dataset.7. Synthesis. To date wild plant-pathogen studies have focused on the epidemiology of the pathogen and its effect on individual plant fitness. Here we have established a link to the impact of the pathogen on the long-term dynamics of host

Optimizing Plant Disease Management in Agricultural Ecosystems Through Rational In-Crop Diversification

“…Disease severity and PDR data were fitted to statistical models and evaluated through the Akaike information criterion (AIC, Sakamoto et al, 1986) if more than one model was statistically supported. In the evaluation, models with a smaller AIC value are better but were not considered to be significantly so if the difference of AICs between models was less than two units (Zhan et al, 2021). For data fitted to a quadratic distribution, their modes were estimated and used to determine the optimal mixtures for the best late blight management.…”

The genetic architecture ofArabidopsis thalianain response to native non-pathogenic leaf bacterial species revealed by GWA mapping in field conditions

“…Both wild plant species and crops are consistently challenged by pathogens, making infectious disease often the major selective agent in nature [1][2][3][4][5]. In wild species, pathogen attacks can significantly decrease the number of offspring, which in turn affects host population growth rate [6][7][8]. Yield losses resulting from pathogen attacks can reach several tens of percent in crops [9][10][11][12], thereby threatening global food security [10,13].…”