Jim Myers accomplished an unprecedented feat in 2011. As a vegetable breeder at Oregon State University, he unveiled the world’s first purple tomato enriched with the same beneficial compound found in blueberries.
Named Indigo Rose, this tomato took Myers and his team a decade to cultivate. It quickly gained popularity among consumers and breeders alike, with its novelty and antioxidant-rich anthocyanin pigment that imparts a purple hue to the fruit.
Since then, Myers has continued to enhance his line of purple tomatoes over the past 11 years. He has introduced four more varieties, including Indigo Cherry Drops, which boasts superior flavor and yield, Indigo Pear Drops, a sweet, pear-shaped fruit, and Indigo Kiwi, which offers improved growth, taste, and resistance to leaf curl. The latest addition is Midnight Roma, a paste tomato that chefs and home cooks alike are using for sauces, released in 2021.
All of these varieties are available as seeds for purchase online, with ideal timing for planting in western Oregon being right about now. While garden centers may have some starts available later in May or perhaps June, seeds are the best option to guarantee getting the desired variety. Soil temperature should be between 60-70 degrees F for optimal growth.
The Indigo Rose tomato has since spawned 50 descendants, with five developed by Oregon State University and the remainder by private breeders utilizing Myers’s germplasm. While heirloom tomatoes like Cherokee Purple, Black Krim, and Black Prince have long been familiar to gardeners, their purple coloration results from pheophytin pigmentation that lacks anthocyanins.
Myers and his students undertook the arduous task of manually crossing plants exhibiting the potential to manifest the purple gene in their offspring. They selected the most promising candidates from each season’s harvest and continued the crossing process until they developed a superior purple tomato that was suitable for distribution to both breeders and home gardeners.
Myers, who has served OSU for over 26 years and developed a green bean variety employed by processors on 80% of Oregon’s agricultural acreage, initially created the cross that gave rise to Indigo Rose utilizing genetic material from wild tomatoes maintained in the germplasm collection at the University of California, Davis. The original stock was collected in the 1960s by two breeders in Chile and the Galapagos Islands.
After crossing wild tomato varieties with cultivated ones, breeding research was put on hold until Jim Myers began his work in the early 2000s. The impetus for his research came from graduate student Carl Jones, who was studying the health benefits of tomatoes and observed an unfamiliar purple hue in the germplasm of the wild species held at U.C. Davis.
Myers and his team set out to create a tomato that combined the health benefits of anthocyanins with desirable traits of a homegrown tomato, with a focus on disease resistance. Once they produced an edible purple tomato, they conducted field evaluations over the course of 11 years, monitoring the growth and production of the plants. Every year, they crossed the tomatoes with the most intense purple expression, ultimately selecting the most promising specimens from the field. None of the tomatoes were produced using genetically modified genes.
According to Myers, the team’s most significant breakthrough occurred when they began crossing purple fruit sources originating from different wild species. They selected tomatoes that exhibited the most intense expression of purple, were resistant to decay and verticillium wilt, and would last longer in the field than typical tomato fruit.
In contrast to Myers’s traditionally bred tomatoes, a genetically modified purple tomato from Europe was approved by the U.S. Department of Agriculture last year and is expected to appear on the market this year under an as-yet-unnamed brand. However, this product will not be available in Europe, where GMO products are prohibited.