Projects on herbicide resistance in ryegrass
Understanding adaptive evolution to herbicides
Intense selection pressures result in major evolutionary changes. This is best exemplified by pests responding to pesticides or bacteria to antibiotics. While the cause of these evolutionary changes is genetic, the consequence is demographic: the selection of a mutation increasing fitness drives the population dynamics. The most tolerant individuals increase in abundance and the population grows again, relegating the last selection pressure to the annals of past evolution; this is the fundamental paradigm of evolutionary biology.
Exploring the potential of gene drives to restore herbicide susceptibility
Herbicide resistance is a growing problem. As resistance spreads, herbicides lose their efficacy and struggle to control weeds. This can reduce crop productivity and can represent a costly loss for farmers. In order to make currently ineffective herbicides useful again, we need to reintroduce susceptibility.
To reintroduce susceptilibty, we need to be able to change the allele frequencies at the population scale. Simply releasing susceptible weeds will not change the population as the same problem persists, susceptible plants are selected against and resistant plants increase in frequency. By making it so that only susceptible alleles are passed on, it is possible to change the allele frequency at the population scale. This is the core concept of a gene drive.
A gene drive, a genetic element capable of self replication, is able to edit a specific allele and replace it with itself. Through this method, progeny of a gene drive individual will always inherit a copy of the gene drive, as will their progeny. After a number of generations, the gene drive may fixate.