Impact of disease on diversity and productivity of plant populations

Abstract

Summary Experiments were conducted on the role of intra‐ and inter‐genotypic competition in ecological processes operating at the population scale in diseased plant populations.Combinations of Arabidopsis thaliana genotypes showing variation for phenotypic traits relating to competitive ability and pathogen compatibility were infected with the oomycete Hyaloperonospora arabidopsidis and Turnip yellows virus in separate experiments. Plant fitness and competitive ability were estimated from phenotypic measurements.Pathogen‐induced reduction in competitive ability for susceptible genotypes increased the competitive ability of resistant genotypes, resulting in maintenance of yield via competitive release. The two diseases had different effects on competitive interactions between plants. In experiments involving the oomycete, the highest yields were produced by mixtures of two weakly competing genotypes.The Arabidopsis model system has elucidated the ecological processes by which compensatory competitive interactions can increase the buffering capacity of plant populations under pathogen attack. Highly competitive genotypes may not maximize the productivity of the population as a whole, as they may over‐yield at the expense of less competitive, more productive genotypes. The specific outcomes of competitive interactions cannot be generalized because they depend on the disease and the host genotypes.

Increased yield stability of field-grown winter barley (Hordeum vulgare L.) varietal mixtures through ecological processes

“…Element was the only variety to display no signs of lodging in monoculture and therefore likely to have contributed to reduced lodging and increased seed production of neighbouring plants in mixtures by facilitation. Previous work with the model plant Arabidopsis thaliana demonstrated that genotypes with the highest yield potential are often the most competitive, allowing them to over-yield in mixture through a reduction in the intensity of competition compared to a monoculture of the high-yielding genotype ( Creissen et al., 2013 , Creissen et al., 2015 ). In this study, the six-row cultivar, which had the highest yield potential, was indeed responsible for compensation observed within the mixtures.…”

“…Facilitation can occur within mixed populations if the fitness of neighbouring plants is increased through inter-plant interactions such as provision of shade and deterrence of pests ( Callaway, 1995 ). When weaker individuals are harmed by environmental stress, stronger plants can increase their yields through compensation via competitive release (a reduction in competition) ( Tilman, 1996 , Creissen et al., 2013 , 2015 ).…”

Plant–Soil Feedback: Bridging Natural and Agricultural Sciences

“…For example, traits which influence the phenolic profile of roots are important predictors of defense against root herbivores [39,40]. Hence, targeting specific chemical root traits through conventional breeding or genomic engineering might maintain yield under pathogen pressure in agricultural systems [41]. Exciting opportunities for new crop defense solutions also exist through re-introduction of wild plant traits into domesticated crops, and for exploring the coevolution of defense mechanisms with microbial communities in wild relatives in their native habitat [35,42].…”

Changes in insect biodiversity on rehabilitation sites in the southern coastal areas of Java Island, Indonesia

“…In a normal stand, the number of seedlings must be proportionally higher than the bigger ones (Haneda et al 2013). Less number of seedlings were probably due to the physiological characteristics of the species that lower the growing capacity under dense stands, less viable seeds, and other environmental threats, including pests and diseases (Creissen et al 2016). In such conditions, silvicultural treatments such as canopy opening and seedling enrichment are required (Widiyatno et al 2014); otherwise, the long-term sustainability may be compromised.…”