Epidemiology in Mixed Host Populations
Open Access
- 1 November 1999
- journal article
- Published by Scientific Societies in Phytopathology®
- Vol. 89 (11) , 984-990
- https://doi.org/10.1094/phyto.1999.89.11.984
Abstract
Although plant disease epidemiology has focused on populations in which all host plants have the same genotype, mixtures of host genotypes are more typical of natural populations and offer promising options for deployment of resistance genes in agriculture. In this review, we discuss Leonard's classic model of the effects of host genotype diversity on disease and its predictions of disease level based on the proportion of susceptible host tissue. As a refinement to Leonard's model, the spatial structure of host and pathogen population can be taken into account by considering factors such as autoinfection, interaction between host size and pathogen dispersal gradients, lesion expansion, and host carrying capacity for disease. The genetic composition of the host population also can be taken into account by considering differences in race-specific resistance among host genotypes, compensation, plant competition, and competitive interactions among pathogen genotypes. The magnitude of host-diversity effects for particular host-pathogen systems can be predicted by considering how the inherent characteristics of a system causes it to differ from the assumptions of the classic model. Because of the limited number of studies comparing host-diversity effects in different systems, it is difficult at this point to make more than qualitative predictions. Environmental conditions and management decisions also influence host-diversity effects on disease through their effect on factors such as host density and epidemic length and intensity.Keywords
This publication has 49 references indexed in Scilit:
- Effects of induced resistance on infection efficiency and sporulation of Puccinia striiformis on seedlings in varietal mixtures and on field epidemics in pure standsEuropean Journal of Plant Pathology, 1996
- Effect of genotype unit number and spatial arrangement on severity of yellow rust in wheat cultivar mixturesPlant Pathology, 1996
- Mixed Genotypes Combined with Copper Sprays to Manage Bacterial Spot of Bell PeppersPhytopathology®, 1996
- Induced resistance in host mixtures and its effect on disease control in computer‐simulated epidemicsPlant Pathology, 1995
- Host mixture efficacy in disease control: effects of lesion growth analyzed through computer‐simulated epidemicsPlant Pathology, 1994
- Dispersive Epidemic Waves: I. Focus Expansion within a Linear PlantingPhytopathology®, 1993
- Pseudocercosporella herpotrichoides, Fusarium spp. and Rhizoctonia cerealis stem rot in pure stands and interspecific mixtures of cerealsCrop Protection, 1992
- Anthracnose Development in Pure and Mixed Stands of the Pasture LegumeStylosanthes scabraPhytopathology®, 1991
- Spore Dispersal and Plant Disease Gradients; a Comparison between two Empirical ModelsJournal of Phytopathology, 1987
- The spread oi Erysiphe graminis f. sp. hordei in mixtures of barley varietiesPlant Pathology, 1984