A "Plant Paternity Test" To Limit Global Food Wastage

Dr Wirulda Pootakham, Royal Academy of Engineering, LIF fellow, is a Thai entrepreneur who has created a "plant paternity test" – HybridSure – which enables seed production companies to assess the genetic purity of hybrid seeds faster than traditional methods. Using DNA marker technology, the companies can be sure that only high-quality hybrid seeds make it to the market.

Technology Networks spoke with Pootakham to learn more about the plant paternity test, why a DNA-based assessment of seed purity is favorable and the next steps in developing HybridSure.

Molly Campbell (MC): For our readers that may be unfamiliar, please can you discuss some of the current approaches to breeding and where they perhaps fall short?

Wirulda Pootakham (WP): The current breeding approach (for crop species without genomic resources) is the conventional method where you develop elite cultivars through recurrent selections of individuals with desirable characteristics. Breeders need to carry out a field test to select the plants with a desired trait and use them as parents for the next round of breeding. Typically, three to four rounds of selections are carried out before an elite cultivar is obtained. The drawback of this approach is that field tests are time-consuming, laborious and expensive. The use of DNA markers (called marker-assisted breeding) helps shorten each selection cycle, enabling a rapid development of a new elite cultivar.

MC: Why have you developed a "plant paternity test", HybridSure?

WP: Hybrid vegetable seeds with desirable characteristics are produced by crossing two very good parental varieties – that’s why they are called hybrid. Seed production companies have to make sure that the hybrid seeds they are selling came from the intended parents – sometimes, they had the wrong dad! A conventional approach for seed purity test (aka paternity test) is a “grow-out” test involving the germination of hybrid seeds to obtain full-grown plants for a visual assessment of morphological characteristics. This process is laborious, extremely time-consuming (up to 12 months) and not very accurate. HybridSure is a DNA-based purity testing service that uses molecular markers to validate the genetic purity of hybrid seeds. It is a quick (two to three days) and accurate method for ensuring that only high-quality hybrid seeds are released to the market.

MC: Please can you describe how the test works?

WP: Instead of relying on morphological characteristics, such as fruit size or sweetness, HybridSure uses unique DNA markers to confirm the parentage of each hybrid line. A HybridSure test begins with the isolation of DNA from either hybrid seeds or seedlings. Extracted DNA is then used as a template for a polymerase chain reaction based assay to identify the genotype (DNA composition) of each hybrid seed. Finally, the percentage of seed purity is calculated for each batch of seeds tested.

MC: How does the test enable the seed production companies to assess the genetic purity of their hybrid seeds up to 100 times faster than traditional methods?

WP: The conventional seed purity testing approach takes 6-12 months, while our HybridSure technology can perform the same test within two to three days. A DNA-based approach bypasses the need to obtain full-grown plants for visual assessment. The assay can be performed directly on the seeds in a high-throughput fashion, allowing thousands of samples to be tested in just a few days instead of several months.

MC: What are your next steps in developing HybridSure?

WP: We are currently providing the service to seed production companies that have DNA extraction capabilities and can provide us with DNA samples. We are in the process of developing methods for high-throughput DNA extraction. In the near future, we hope to expand our service to all seed production companies, including those outside of Thailand.

MC: What would your advice be, as a female scientist and entrepreneur, to your female peers?

WP: I am fortunate to be working in an environment where a number of successful scientists and entrepreneurs are women, and I have never been treated unfairly because of my gender. When a challenging opportunity knocks on my door, I naturally welcome it without thinking or worrying about the gender issue. I always think of myself as a person, not a woman. My advice to other female scientists/entrepreneurs is to develop a mindset where you look at things in a gender-neutral fashion. Do not be intimidated to enter the male-dominating space. We are all human being, and we can achieve anything we set our mind to!

Wirulda Pootakham was speaking to Molly Campbell, Science Writer, Technology Networks.