Researchers at the University of Zurich have made a groundbreaking discovery: using biodiversity within a plant species can effectively reduce crop damage from herbivores, potentially lessening the need for chemical pesticides. This fascinating field study highlights the importance of biodiversity in sustainable agriculture and the intricate relationships between plants. By exploring the concept of ‘associative resistance,’ the researchers have uncovered a promising approach to balancing food security and environmental preservation.
Plants Have The Power to Work Together
As human beings can, so can plants communicate with the people around them. In a large field study the team of scientists from Universität Zürich have shown that when plants of different genetic types are mixed and planted in the same plot, this improves resistance to pests and diseases. The discovery, called ‘associative resistance,’ could be a game changer in the practice of sustainable agriculture.
The researchers were able to do so by randomly mixing and planting 6490 individuals of 199 genotypes from different localities of the model plant Arabidopsis thaliana. Collecting 52,707 of these insects on the plants laboriously and by hand yielded a truly unprecedented dataset with which to base their analysis. Researchers used a new approach known as ‘Neighbor GWAS’ to find many genes that are specific for the interaction between individuals in close proximity, providing insights into how associative resistance works at the molecular level.
Creation of these genotype combinations will facilitating in predicting favourable genotypes.
A central obstacle to leveraging associative resistance is that nobody knows which combinations of plant genotypes perform the best together. There are 19,701 entries to analyze when one has 199 genotypes. To solve this, the researchers used a machine learning technique to predict herbivore damage between different genotype pairings.
In another extensive field experiment, the team paired three levels of associative resistance they had predicted by planting ~2,000 plant individuals in genotypic pairs. The results were astonishing; mixed with two genotypes, the highest and second-highest associative resistance level reduced herbivore damage by 24.8%, and 22.7% respectively from the case where a single genotype is planted. This finding has significant implications for the utilization of biodiversity to modulate ecosystem functioning and reduce the dependency on chemical pesticides as reliant means to increase crop yields.
Striking a balance between food security and environment-friendly practices
These consequences carry significant weight, as the research team points out in their paper. This study, published in Nature Communications, presents a more hopeful answer for the challenge of feeding a growing global population while also protecting the planet. Employing associative resistance has the potential to increase crop yield moreover without utilizing hazardous pesticides, therefore additionally associatively with supporting biodiversity variety of the world encompassing insects.
The researchers say that for key crop species with known genomes – such as wheat or rice – new method can be applied to make selection predictions of which specific plant genotypes should be combined in mixtures to optimize associative resistance. That, in turn, could mean even higher yields plus less spraying of pesticide — a two-fer for food security and the environment.
