Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (2.0 MB bytes)

Title: Breaking primary seed dormancy in Gibbens' beardtongue (Penstemon gibbensii) and blowout penstemon (Penstemon haydenii)

Author: Tilini, Kassie L.; Meyer, Susan E.; Allen, Phil S.;

Date: 2016

Source: Native Plants. 17(3): 256-266.

Publication Series: Scientific Journal (JRNL)

Description: This study established that chilling removes primary seed dormancy in 2 rare penstemons of the western US, Gibbens’ beardtongue (Penstemon gibbensii Dorn [Scrophulariaceae]) and blowout penstemon (Penstemon haydenii S. Watson). Wild-harvested seeds were subjected either to moist chilling at 2 to 4 °C (36-39 °F) for 0, 4, 8, 12, and 16 wk or to approximately 2 y of dry storage. Seeds of both species were dormant at harvest and responded positively to chilling. Penstemon gibbensii germination increased linearly with length of chilling, and collections from sites with longer winters required a longer chilling period to break dormancy. With longer chilling durations, most seeds germinated during the chilling treatment. Penstemon haydenii germination increased to nearly 100% after 4 or more wk of chilling followed by incubation under a cool, diurnally alternating temperature regime (10-20 °C [50-68 °F]) but did not germinate during chilling treatments regardless of duration. Under constant (15, 20, 25 °C [59, 68, 77 °F]) or warmer (15-25 °C, 20-30 °C [59-77 °F, 68-86 °F]) alternating post-chilling temperature regimes, germination was consistently < 15%. Without chilling, dry storage increased germination (from 0-15%) in P. haydenii. By contrast, P. gibbensii seeds showed no increase in germination following dry storage, where germination in both recently harvested and 2-y-stored seeds averaged 16% without chilling. These insights will assist propagation and reintroduction strategies for restoring populations of these rare species.

Keywords: alternating temperature, cold stratification, dry after-ripening, habitat-correlated, pre-chilling, seed germination, Scrophulariaceae

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

XML: View XML

Citation:


Tilini, Kassie L.; Meyer, Susan E.; Allen, Phil S. 2016. Breaking primary seed dormancy in Gibbens' beardtongue (Penstemon gibbensii) and blowout penstemon (Penstemon haydenii). Native Plants. 17(3): 256-266.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.