Researchers from the University of Zurich have discovered a groundbreaking solution to reducing crop damage from herbivores: using biodiversity instead of pesticides. Their comprehensive field study, published in the journal Agronomy for Sustainable Development, reveals how the genetic diversity of crops can be leveraged to enhance associative resistance and protect against pests. This innovative approach offers a promising path to ensuring food security while preserving the environment and biodiversity.
Exploring the World of Plant Interactions
And the fundamental insight from the work of Shaunney Jari and colleagues is that, yes like all living organisms.. plants do interact with other members of their community. When you grow two or more genetic types of the same species and combine them and plant them next to each other, if can happen that some of these combinations are significantly more resistant against pests (such as aphids) or diseases. So called “associative resistance” is one example of this biodiversity effect.
To do so, the research team followed up with large-scale plant cultivation experiments over 2 years using a variety of 199 genotypes of the model plant Arabidopsis thaliana. Mixing and planting more than 6400 individuals at random allowed them to gather an extraordinary dataset, meticulously counting 52,707 insects on the plants. It was on this breadth of data that their landmark findings lay.
Anticipating Good Genotype Matches
Previously, there has been no general way to assay the genetic architecture of locally-adapted associative resistance between neighbouring plant individuals. Using this method, which they have termed “Neighbor GWAS,” a team of researchers led by Yasuhiro Sato accomplished something. It uses a physics model to describe how plant individuals interact and investigates the consequences on herbivore damage of predation, if adjacent individuals have identical or establishing genetic sequences.
With this clever method, the researchers found dozens of host-written genes related in these cross-plant exchanges. Subsequently they used machine learning to predict levels of associative resistance for a range of genotype combinations providing a basis for the selection and deployment of cultivars with minimal risk.
Benefiting from Biodiversity
A second large-scale field experiment involved planting about 2,000 plant individuals in pairs in the field from genotypes they suspected would differ in their level of associative resistance given the results of the first greenhouse study. The mixture of two genotypes decreased herbivore damage by 24.8% and 22.7%, respectively, for the highest and second-highest predicted associative resistance levels when compared with cultivation of a single genotype (results were significant).
In this aspect, the present findings underscore two significant aspects of biodiversity. For one, higher crop diversity in the genes can form a natural defense against pests meaning pesticides which harm both people and wildlife would no longer be needed. Second, our promotion of this biodiversity-based strategy fits within a larger conservation ecosystem that works to save ecosystems and beneficial insects. “From the contextual philosophical viewpoint, this can be seen a marker in the study of interaction between plant individuals and also provide a great example that biodiversity is indispensable for full-function — in two aspects.
