Reports of cherries roasting in orchards in Western Canada made headlines during the record-breaking heat wave in June. More recently, a report from the Intergovernmental Panel on Climate Change (IPCC) warned that extreme weather events are likely to become more frequent due to the accelerating and intensifying effects of climate change. The multiple days of extreme heat that hit Western Canada resulted in widespread damage to cherry, apple, peach and apricot crops. However, more concerning than the damage done to fruit by high heat is the danger it poses to the people who harvest them due to the risk of heat stroke. For fruit growers, concerns are growing about their ability to continue to grow and harvest fruit within the regions they currently farm if extreme heat events become the new norm.
Many fruits that we consume, like apples, cherries, plums and peaches, are perennial crops which means that they live for more than two years. Perennial fruit crops often take a long time to produce fruit; in the case of avocado, it can take 15 years after they are planted for them to produce fruit. In apple, this time period, referred to as the juvenile phase, lasts around 3-5 years. Perennial crops are slow to mature and likewise breeding new perennial fruit crops is a slow endeavour. Annual crops, like corn, rice and wheat, complete their life cycle within a year and therefore new cultivars can be turned over quickly. The long juvenile phase for perennial fruit crops is one of the largest limiting factors to being able to study their genetics and breed new cultivars. Speeding up the breeding process so that we can develop new cultivars in time to meet the rapidly evolving climate will be crucial to ensuring these crops can continue to grow. Over the next 25 years, the same period it can take to develop a new apple cultivar, we are likely to surpass 2°C of global warming according to the IPCC. In short, the current rate of climate change is outpacing our current rate of cultivar development.
Although we are facing unprecedented climate change, we also now possess an unprecedented ability to efficiently alter the genomes of virtually any crop. Through genetic modification and gene editing we can adapt our crops to be more resilient to changing climate. Genetic modification usually involves the introduction of genes from one species to another. Gene editing involves tinkering with the genes that are already present within a species, which is why in many countries gene editing is not subject to the same stringent regulations that govern genetically modified crops. To date, there are no gene-edited apples available commercially and the only genetically-modified apple available is the Arctic Apple, which was modified to improve fruit quality by rendering the apple non-browning. Despite preliminary studies demonstrating potential to use genetic modification to improve climate adaptation traits like drought and salt tolerance in apple, none have materialized into improved cultivars in farmers’ fields.
The lack of commercially grown genetically-modified fruit crops can in part be attributed to the general difficulty in breeding perennial crops, the regulatory burden that comes with developing a genetically-modified cultivar and public opposition towards this technology. However, there is increasing hope that public perception of genetic modification is changing, and that gene editing will not suffer from the same disapproval from the public. Genetic modification and gene editing are shaping up to be essential tools alongside traditional breeding methods to mitigate the effects of climate change on agriculture. The future of fruit production likely hinges on our willingness to embrace the potential of these technologies.
Photo by Pascal Debrunner on Unsplash