Saved seeds may not give desired results

By Reeser Manley,
Posted June 04, 2010, at 5:43 p.m.

Last fall I participated in a tour of the schoolyard garden at Troy Howard Middle School in Belfast. At the end of the tour, each participant was given a small packet of Black Prince tomato seeds collected by students from plants growing in the Troy Howard garden.

Last week, my students planted seedlings grown from these seeds in our new Eastport Schoolyard Garden.

Black Prince is an heirloom tomato variety from Irkutsk, Siberia. It is highly recommended for gardens in cool climates, its fruit sought after by many professional chefs. The round 3-ounce tomatoes ripen to a deep blackish-chocolate brown with a flavor as deep, fruity, and rich as the color.

This coming fall, my high school students could save seeds from several of our Black Prince tomatoes, packaging the seeds in small envelopes as gifts for garden friends. By doing this, they could complete the circle of effort necessary to preserve a vegetable variety unique in flavor and regional adaptability, and our garden could become a link in a chain of gardens sustaining the genetic diversity of tomatoes.

Planting Black Prince tomatoes was not the only seed-saving enterprise in the Eastport Schoolyard Garden last week. Diana Boone brought her kindergarten class over from across the street to plant pumpkin seedlings in the Garden. The children had collected the seeds last October while carving jack-o-lanterns, then waited until late April to germinate them under lights in the classroom. They transplanted their seedlings to individual pots in early May. Last Friday, they too closed the circle with the help of several high school student-mentors.

But will either of these student efforts meet with expected results? Could the kindergartners harvest jack-o-lantern pumpkins in October? Will the collected Black Prince tomato seeds produce Black Prince seedlings next spring?

For pumpkins, the answer is clear. The species Cucurbita pepo includes pumpkins, all summer squashes (zucchini, scallop, crookneck, etc.), acorn squash, spaghetti squash, and small gourds. All of these can cross-pollinate and thus must be grown in isolation by the seed saver. Not knowing if the children’s jack-o-lantern pump-kins were isolated or if they were grown in the same field with related cucurbits, it is impossible to know what to expect in fruit types come October. We could be looking at some very interesting Halloween pumpkins, both in color and shape.

For our Black Prince tomatoes, the issue is similar. Tomatoes, while self-fertile, are not always self-pollinated. It depends on the bumblebee, where it was before it visited the Black Prince flower. The students planted another tomato variety, Sungold, in the same garden, only a few feet away from the Black Prince, and it is highly likely that any bumblebee foraging in the garden would carry pollen from both varieties. Seeds collected from the Black Prince fruits this year could produce plants bearing a wide variety of fruit types next year.

If the students were serious about producing seeds of Black Prince, they would need to isolate several flowers in small blossom bags and hand pollinate them with mechanical vibrators that mimic the “buzz sonication” of the bumblebee (a technique frequently used by commercial greenhouse tomato growers until the mid-90s when use of purchased bumblebees became dominant). The hand-pollinated flowers and resulting fruits would need to be carefully labeled.

This would make an interesting class project for an ambitious student, one willing to do some of the work during the summer when the tomatoes bloom. Would an electric toothbrush do the job?

When saving seed of heirloom varieties, it is important to maintain the variety’s genetic vigor. This cannot be done by collecting the seed from one or two fruits. Desirable traits are distributed among many plants in cross-pollinators and saving the seed from fruits on several plants is required for most varieties.

http://bangordailynews.com/2010/06/04/living/saved-seeds-may-not-give-desired-results/ printed on August 1, 2014