Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 8/15/2006
Publication Date: 11/6/2006
Citation: Seiler, G.J. 2006. Germination and viability of wild sunflower species stored at room temperature for 20 years. International Crop Science Society of America Annual Meeting, November 12-16, 2006, Indianapolis, IN. ASA, CSSA, and SSSA, Madison, WI, Annual Meetings Abstracts [CD-ROM]. Interpretive Summary:
Technical Abstract: Dormancy in achenes of wild sunflower (Helianthus) species ensures that they do not germinate in temperate climates until conditions are optimal for seedling survival. Once dormancy is imposed, it suppresses germination, allowing the achenes to survive in nature for years. It is not known what detrimental effects storage of achenes at less than optimal conditions for long periods of time would have on their viability and germination. The objectives of the study were to test the viability and germination of achenes of two wild annual sunflower species, H. annuus and H. petiolaris, stored at room temperature (20-22 C) at a relative humidity of 22% in a bell jar in the laboratory for 20 years, and to determine the efficacy of a germination technique using gibberellic acid (GA3) as a medium to overcome dormancy and increase germination. The tetrazolium test was used to test the viability of the achenes of the wild species. Wild H. annuus had 89% positive staining indicating achene viability, while H. petiolaris had 80%. Germination using a standard technique for wild H. annuus was 13%, while H. petiolaris had only 1% germination. Germination of fresh achenes 20 years ago was 35% for H. annuus, and 47% for H. petiolaris. Treatment of the wild achenes with 1mM GA3 for one hour resulted in an increased germination of the wild H. annuus from 13% to 88%, and H. petiolaris from 1% to 85%. Viability testing indicated that the achenes were alive, but due to dormancy, they had very low germination after their long storage period. However, utilization of a germination medium to enhance germination of wild species which have been stored for long periods at less than optimal storage conditions can facilitate their use for improvement of cultivated sunflower in breeding programs.