says Bird. "They live in sandy soils 

 that have almost no nutrients. You 

 have whole groups of plants that have 

 learned to grow and flower and 

 reproduce fairly well under what are 

 pretty crummy conditions. 



"These are the kinds of conditions 

 that a lot of agronomists would like to 

 start trying to adapt plants for so that 

 in regular agriculture, we don't need 

 to use so much fertilizer. 

 Or we can use brackish- 

 water wells in western 

 states where the wells 

 have now gone from 

 freshwater to brackish in 

 nature." 



Disease resistance is 

 another benefit of 

 tweaking the genes of 

 marine plants. John 

 Gallagher and Denise 

 Seliskar, Sea Grant 

 scientists at the Univer- 

 sity of Delaware, are 

 developing more hardy 

 varieties of dune plants 

 for the Eastern Sea- 

 board. For example, 

 American beachgrass is 

 the major stabilizing 

 plant on ocean dunes of 

 the mid- and North 

 Atlantic, but it is highly 

 susceptible to disease 

 caused by pathogenic 

 nematodes. Through in 

 vitro selection, the 

 botanists are trying to 

 isolate nematode- 

 resistant plant lines. 

 They are also tinkering 

 with a more cold- 

 tolerant strain of sea 

 oats, which are less susceptible to 

 nematode attack. Sea oats are natu- 

 rally concentrated along the Southeast 

 Atlantic and Gulf coasts, but 

 Gallagher and Seliskar hope to extend 

 the species beyond its northern range. 

 They have planted a genetically 

 manipulated crop of sea oats on a 

 dune at Broadkill Beach, Del., that has 

 survived for five winters. 



Although mutations occur and are 

 even encouraged in some research, 

 micropropagation is generally 

 considered a "true" method of 



replication. Through this vegetative or 

 asexual process, culturists produce 

 genuine clones that are identical to the 

 donor or parent plant. Whether the 

 goal is a homogenous supercrop of 

 leafy Boston ferns or stands of sea 

 oats with extensive root systems, 

 standard tissue culture can produce it. 



The possibilities are tantalizing. 

 But the implications and concerns are 



Photo courtesy of Michael Kan 



Micropropagated pickerelweed, a freshwater wetland 

 blooms in the field. 



multiplying as fast as the plants. Some 

 ecologists worry about the use of 

 cloned plants to restore the environ- 

 ment; they are uneasy about a possible 

 lack of genetic diversity in replanted 

 seagrass beds and marshes. Others 

 argue that we don't even know what 

 level of diversity exists within native 

 populations. 



Again, scientists are scrambling 

 to provide answers. 



Through genetic mapping and 

 DNA fingerprinting, researchers are 

 trying to paint a picture of the genetic 



diversity that exists in the wild. 



Just as a group of people in a 

 room show differences in inherited 

 eye color, height, body proportions 

 and metabolism, individual plants 

 within a habitat can also show 

 variation, says Bird. The accumulation 

 of these differences is the amount of 

 genetic diversity that occurs within a 

 species. 



Early data showed 

 little genetic variation 

 within seagrasses and 

 other wetland plants, 

 but the powerful lens 

 of biotechnology is 

 beginning to provide 

 better resolution, Bird 

 says. Restoration 

 biologists and tissue 

 culture scientists 

 anxiously await the 

 results of these genetic 

 analyses. Once they 

 understand how much 

 diversity is present 

 in wetland plants, 

 micropropagators 

 can aim to develop 

 multiple lines of 

 genetically different 

 plants in culture. 

 The result may be an 

 extensive library of 

 replacement plant 

 stock appropriate for 

 a wide range of 

 restoration. 



But with all its 

 potential, microprop- 

 agation is not creating 

 "roboplants" com- 

 pletely immune to the 

 ravages that have 

 weakened marine environments in the 

 first place. 



"Until we correct the ecological 

 causes of habitat loss, we're not going 

 to be able to restore the habitats and 

 have them remain," says Bird. "And 

 so this is going to have to be the first 

 real goal of any kind of long-term 

 management of our bays and estuaries. 



"It's a tough battle, but we have 

 to keep pointing out that there's 

 tremendous value — tremendous 

 economic value — in all of our 

 wetlands." □ 



plant, 



COASTWATCH 21 



