'Dark Star' Zucchini
|Title||'Dark Star' Zucchini: Breeding Open-Pollinated Zucchini for Market Growers|
A zucchini variety adapted to organic farming conditions that meets customer demand for quality and uniformity (dark green and cylindrical, with good length and diameter) and is easier to harvest than other OP varieties.
|Farm Partner(s)||Eel River Farms|
In the 1990s Bill Reynolds and Donna Ferguson of Eel River Farms in Loleta, California, discovered that the zucchini variety their customers had come to enjoy and rely on from their farm was no longer available. The variety was ‘Raven,’ and Bill and Donna decided to start their own breeding project to identify a reliable, open-pollinated organic replacement.
The initial breeding work resulted in a new open-pollinated variety, which Bill and Donna named ‘Black Eel.’ It was sold through Seeds of Change. But it lacked uniformity despite its good yield of dark green, well-proportioned fruits, and was not an appropriate fit for market growers. Seeds of Change realized that if they were to offer a zucchini that was commercially viable for the market farmers seeking organically grown seed, that they would have to ratchet up the breeding effort to produce a variety with the best traits of ‘Black Eel’ without the variability. Therefore, Seeds of Change chose to fund a participatory plant breeding project that brought Bill and Donna’s advanced agronomic and market knowledge of zucchini with OSA’s expertise in breeding cross-pollinated vegetable crops for organic farms.
After nearly a decade of this breeding work, a new variety called ‘Dark Star’ was commercially released in 2007 through Seeds of Change to meet the growing demand for zucchini seed adapted to organic systems.
Breeding Needs and Goals
The breeding project goals were to produce a plant type that did not bush and had good angle for the fruit to set and a low degree of petiole (stem) spines. The aim was also to produce fruit that was dark green and cylindrical, with a good length to diameter ratio for a uniform harvest.
Breeding Methods and Timeline
‘Dark Star’ zucchini is the result of combining the best qualities of ‘Raven’ with those of an older, standard open-pollinated variety called ‘Black Beauty.’ Bill and Donna began their breeding project by planting a large field of both ‘Raven’ and ‘Black Beauty.’ For the next four years they saved and replanted seed from the best plants derived from these crosses, mixing the seed from the best plants each year and replanting them the following spring. This technique is known as “mass selection” and it retains much of the genetic variation in the plots. By retaining genetic variation, you leave room for genetic selection in the future so that plants can continue to adapt to changing climates and production and market needs. The disadvantage is that it is a slower breeding method.
In the summer of 2003 we decided that to produce a more uniform market class zucchini, a breeding technique known as “recurrent selection” would be coupled with Bill and Donna’s knowledge of market class zucchinis. We planted more than an acre of ‘Black Eel’ with border rows of ‘Raven’ as a means of comparison. Bill and Donna identified approximately 50 good ‘Black Eel’ plants and then self-pollinated each of those plants. Bill and Donna made 26 successful hand pollinations and most of these produced ample seed. This seed was harvested, cleaned, and dried separately from each fruit and was placed into 26 individual envelopes for planting the following season.
In the summer of 2004 seed from each envelope was planted into its own row. The plants in these rows were all different in appearance, revealing the genetically recessive traits that often are “hidden” behind the more prevalent dominant traits that usually are the distinguishing characteristics of the variety. Bill and Donna harvested the plot as a normal commercial field for two to three weeks to get to know the rows and the kind of uniformity, shape, and color of fruit as well as the plant characteristics. They then identified four to five rows out of the 26 with both superior fruit and superior plants. The best plants in the rows were then allowed to intermate openly and set fruit. The intermated seed was harvested from the rows separately into separate bags.
In 2005 the seed from these rows was planted in two large blocks along with the original ‘Black Eel’ and ‘Raven.’ Bill and Donna harvested this field as a crop while scrutinizing it for all of their desired agronomic and fruit traits. While all of the families had a high percentage of superior plants and superior fruit, one of the families started to emerge as a consistently excellent type through the scrutiny of multiple commercial harvests. The family would be finished and released in 2007 with the name ‘Dark Star.’
Breeding new vegetable varieties is a multi-year process. Funding for the 'Dark Star' Zucchini project has come from various sources throughout the research.