In a recent webinar titled “New Breeding Techniques – What are they, and what do they mean for potatoes?“, hosted by Potatoes New Zealand and Otago University, Dr. Rowan Herridge unveiled innovative approaches that could revolutionize potato breeding in New Zealand.

Dr. Rowan Herridge, a Research Fellow at the University of Otago with a rich background in plant biotechnology, shared insights into the future of potato breeding. His work focuses on new breeding techniques (NBTs) aimed at accelerating genetic gains in potatoes, a crop known for its genetic complexity due to its tetraploid nature.

Understanding Potato Breeding and New Breeding Techniques

Potatoes, unlike many crops, are tetraploid, meaning they have four sets of chromosomes. This leads to complex genetic outcomes when breeding, making traditional methods less predictable. Dr. Herridge explained how current breeding practices involve crossing varieties, followed by extensive field trials to identify superior offspring, which could either be released to farmers or used for further breeding.

• Traditional Transgenics: Dr. Herridge touched on the conventional method of inserting foreign genes into potatoes, like Simplot’s Innate potato in the U.S., which modifies sugar content to reduce acrylamide formation.
• Gene Editing (CRISPR): This method allows for precise edits to the potato’s existing DNA, enhancing traits without introducing foreign genes, though it’s limited to the DNA already present.
• New Breeding Techniques (NBTs): Here, Dr. Herridge’s focus, temporary genetic modifications are used to speed up breeding. The key advantage is that the transgenes used are removed in subsequent generations, leaving “null segregants” – potatoes with no transgenes but with improved genetics.

F1 Hybrid Breeding for Potatoes

Dr. Herridge discussed the potential of F1 hybrid breeding, a technique widely used in maize but novel for potatoes. F1 hybrids offer:

• Hybrid Vigor: Enhanced traits in the first generation of offspring, resulting from crossing inbred lines.
• Genetic Uniformity: All seeds from an F1 hybrid are genetically identical, ensuring consistent crop performance.

He introduced the “ChOW” technology (Combined inbreeding and Outcrossing) developed at Otago University, which addresses potatoes’ natural self-incompatibility, allowing for both inbreeding to fix beneficial traits and outcrossing to produce F1 hybrid seeds without transgenes in the final product.

Implications for New Zealand Growers

• Disease Resistance: A primary concern for NZ growers, with Dr. Herridge noting that F1 hybrid breeding could enable the stacking of resistance traits against multiple pathogens, a task much harder with traditional methods due to genetic unpredictability.
• Genetic Gain: The webinar emphasized the importance of genetic gain, showcasing how NBTs and F1 hybrid breeding could significantly outpace traditional methods in improving yield, quality, and resilience of potato varieties.

Future Outlook

While the technology is promising, Dr. Herridge acknowledged the challenges, especially with diseases like common scab, which might require a multifaceted approach beyond just breeding. However, the work at Otago University, alongside international efforts by companies like Solynta and Simplot, indicates a shift towards more sustainable and efficient potato cultivation.

The webinar concluded with an interactive Q&A where Dr. Herridge addressed queries about the availability of diploid potato varieties for breeding and the practical steps towards implementing these new techniques in New Zealand’s potato fields. With continued research and collaboration, these new breeding techniques could soon become a standard practice, offering significant benefits to potato growers and consumers alike.

Source: Potatoes New Zealand YouTube channel. Watch the video here
Image: Credit beauty_of_nature from Pixabay