In this episode of the podcast Shortwave from NPR, host Emily Kwong and producer Hannah Chinn delve into the fascinating world of apple breeding. They speak with Susan Brown, head of the Apple breeding program at Cornell Agrotech, revealing the secrets behind how our favorite apple varieties are created and preserved.
The Science of Apple Cloning
Kwong begins her exploration at Rock Hill Orchard in Maryland, where various apple types like Honeycrisp and Rosalie are picked. Here are some key points discussed:
- Cloning Apples: Apples like Rosalie that you see in different states are actually clones. Every apple tree can be propagated by cutting a leaf and placing it onto a rootstock, resulting in a new tree that is genetically identical to the original.
- Genetic Consistency: Each apple variety, such as Honeycrisp, is essentially a genetic copy, ensuring the apples produced are uniform in taste and appearance.
The Process of Creating New Apple Varieties
To create a new apple variety, like Rosalie, breeders perform careful cross-pollination. Here's how it works:
- Natural Pollination: In nature, apple trees are cross-pollinated by bees, which brings pollen from various trees.
- Controlled Breeding:
- Breeders like Susan Brown manually control which apple trees are used as parents.
- They emasculate the flowers to prevent bees from pollinating them and choose pollen from a second tree for controlled breeding.
- Hand Pollination: Each flower is hand-pollinated with precision to ensure successful crosses, taking immense labor and time—typically around 20 years to develop a new apple variety.
- Selection Process: Each hybrid apple is taste-tested, with the significantly inferior varieties being discarded, sometimes humorously referred to as “spitters.”
Genetic Diversity and Preservation Efforts
Ben Gutierrez, a plant geneticist, discusses the importance of preserving apple genetic diversity:
- Unique Apples: There are an estimated 7,500 apple varieties worldwide, many of which are preserved in a designated USDA orchard that contains 5,000 unique trees.
- Future Research: Scientists are exploring DNA testing in apples to identify genetic markers that determine traits like color and disease resistance. However, the complexity of the apple genome, with over 54,000 genes, presents a significant challenge to fully understand.
Practical Implications for Consumers
The insights from this episode lead to a greater appreciation for the apples we enjoy:
- Consumer Impact: Understanding how apples are bred can enhance consumer awareness regarding the varieties available and their unique flavor profiles.
- Future of Apples: As researchers dive deeper into genetic studies, new apple varieties with improved traits may emerge, possibly transforming the apple market.
Conclusion
The podcast episode "Honey, They Cloned The Apples!" provides a unique glimpse into the intricate world of apple breeding, unveiling the labor, science, and passion that goes into creating the apples we love. From cloning to preserving genetic diversity, the work done by scientists like Susan Brown and Ben Gutierrez is vital to the future of our food supply.
This exploration encourages us to value the science behind our food and look forward to what the future holds for apple enthusiasts everywhere.