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Zebra Phragmites

This variety of Phragmites australis, developed at the University of Delaware Halophyte Biotechnology Center, has two important characteristics. First, it has variegated leaves making it easily distinguishable from wild-type Phragmites. Second, although it readily reproduces vegetatively by rhizomes, few seeds germinate and those that do are not green and die when the seed reserves are consumed during growth (seedlings reach about ½ inch in height). Since no green seedlings emerge in our germination trials, either the plant does not out-cross with wild-type Phragmites nearby or the "non-green trait" is dominant.

These characteristics have advantages over the green, wild-type plants when Phragmites is used in wastewater treatment facilities. First, with their distinctive coloration they are easily identified should they show up in the wild as the result of rhizomes being lost from the plant site during clean outs. This protects both the plant operators and the environmental protection agency officials. Should Phragmites appear near the site where it wasn't a weed before, it can be determined whether its origin is from the wastewater treatment plants. In addition to the visual characteristic, DNA analysis by RAPDs indicates a distinctive banding pattern. Second, although the plants devote extensive resources to flowering, germination is rare and all of the seedlings we have seen thus far are non-green and wither while very small. This means that none of the seeds we have tested carry the potential for spreading the grass.

This variety, which we named Stripes appeared as a somaclonal variant plant regenerated from callus cultures of wild Phragmites. Stripes has been grown at our lab for a decade and recently tested in a sludge drying bed alongside wild-type plants. We expect to have it available as soon as we can make the proper arrangements. We are appreciative of the interest many wastewater treatment facility designers and operators have shown and we will keep those of you for whom we have addresses informed. If you have not been in contact with us and would like to be updated please let us know. (Halophyte Biotechnology Center, College of Earth, Ocean, and Environment, University of Delaware, 700 Pilottown Road, Lewes, DE 19958.)

Sludge beds

E-mail: Jack Gallagher (jackg@udel.edu) or Denise Seliskar (seliskar@udel.edu).

This page was last updated: May 17, 2010
Please report problems with this page to:connie@udel.edu

May 17, 2010