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Research with the Aleutian Shield-fern, Polystichum aleuticum
Reproductive Biology of the Aleutian Shield-fern, Polystichum aleuticum. Final Report by Patricia S. Holloway    to the U.S. Department of the Interior, Fish and Wildlife Service 1994 PDF

Isozyme comparison of the species Polystichum aleuticum and P. lachenense by David Boyd and Patricia S. Holloway. (Unpublished manuscript, University of Alaska Fairbanks. 1993)

This study showed the results of a preliminary research project to examine the isozyme activity of the Aleutian shield-fern, P. aleuticum and its Asian relative, P. lachenense. We analyzed 14 individuals from Adak Island's single population of P. aleuticum and compared them with a single individual of P. lachenense from Tiachung, Taiwan. Our tiny study showed that the 14 individuals from Adak clearly comprise a single genoptye population. All loci were fixed with no indication of variation within the population. Additionally, the isozyme banding for P. aleuticum and P. lachenense were identical. However, we had only one specimen of P. lachenense. Therefore, a lot more data needs to be collected. Lellinger has reclassified P. aleuticum as P. lachenense.


Spore viability and germination of the endangered Aleutian shield-fern, Polystichum aleuticum. by Patricia S. Holloway and David Boyd. (HortScience 28(5):182. Abstr).

Research was initiated in 1990 to study spore viability, spore germination in vitro, and methods of controlled environment culture for the endangered Aleutian shield-fern, Polystichum aleuticum. Spores germinated in 30-45 days on both Knop’s solution and Hoagland’s No. 2 solution in aseptic culture. Germination was most rapid on cultures with less than 6 g/l agar. Cultures with no agar were susceptible to contamination by algae, and sporophyte losses during transfer to greenhouse media were high. Germination rate and subsequent appearance of the first leaf stage did not differ significantly within a medium pH range of 4.7 to 7.0. Spores exhibited a thermodormancy at 25C but germinated well at 18C and required light for germination. Sporophyte transfer from aseptic culture was most successful after true fronds beyond the first leaf stage had developed. A commercial bedding plant mix composed of Sphagnum sp. peat and perlite provided an optimum rooting medium for the ferns.


Other Literature

The Center for Plant Conservation. 2000. America's Vanishing Flora. Stories of Endangered Plants from the Fifty States and Efforts to Save Them. The Center for Plant Conservation, St. Louis, Missouri. p3.

The University of Alaska Fairbanks Georgeson Botanical Garden, PO Box 757200, Fairbanks, Alaska 99775 (907) 474-1944,