How many of you love sweet potatoes, be it baked, boiled, or even as fries? Did you know that this yummy root vegetable has a not-so-sweet genetic history? Yes. After years of research, geneticists have finally sequenced the genome of sweet potatoes, only to discover that this vegetable has guarded its own little secret for years. What is it? Read on till the end to know more.
Sweet potato: A humble root with a genetic twist
Known for its remarkable resilience and adaptability, the sweet potato has fed millions around the world. After surviving several challenges in trying to decode the genome of the sweet potato, scientists have finally succeeded in fully decoding its genome, consisting of six sets of chromosomes. This makes it hexaploid (compared to diploid in humans), making it complex to study its genome. This condition is not just rare but also makes it complex.
In a significant breakthrough by a team led by Prof Zhangjun, the complete genetic makeup of Tanzania, a sweet potato variety from Africa, was established.
The discovery that shocked scientists
Coming to the secret, the sweet potato did not come from a single ancestor. It was, in fact, the result of hybridization, i.e., it originated from multiple wild relatives over time. Each ancestor stitched pieces of their DNA to give a hybrid genome of sweet potato. This hybridization matters because it is what makes the sweet potato genetically diverse and resilient. It could also make breeding. But it could help improve resistance to changing climates and improve nutrition.
Decoding the puzzle
After strenuously and effectively assembling the 90 chromosomes into 6 sets known as haplotypes, scientists could finally get some clarity on their genetic makeup. The sweet potato was 1/3rd  Ipomoea aequatoriensis from Ecuador. A part of its genome was from Ipomoea batatas. Though the actual donor may remain undiscovered.
What makes sweet potato unique?
It isn’t the only plant with genomic segments from ancestors. For instance, wheat has genomic bits of its ancestors in its DNA. Other crops include cotton and bananas. However, those can be found in distinct genomic segments, unlike the sweet potato, where it is intertwined in the same chromosomes, giving rise to a unique genomic architecture. This makes it an allopolyploid (basically a hybrid) but genetically behaves as a single plant! This merging is what gives it its adaptability and resistance.
Furthermore, it has six sets of chromosomes, as seen previously, allowing it to have backups of crucial genes. Even if one gene fails, they have five more copies of the same gene. This can help it resist droughts, pests, and even harsh climates. A similar mechanism was seen in the animal kingdom. Check out a post here. However, this is rarely seen in plants, making them sweetly unique.
This study can help farmers and botanists identify key genes involved in adaptability and resistance, and eventually help produce disease-resistant and pest-resistant crops. Although it is a scientific breakthrough, it requires us to study different varieties of sweet potato from each region, as each of them may have a unique genetic composition.
So, each time you eat a sweet potato, you know there is complex genetics at play. Let me know in the comments what you think about this significant scientific breakthrough.
Fascinating, thanks for sharing