HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Tian, X. Articles by Bailey, T. B. Search for Related Content PubMed Articles by Tian, X. Articles by Bailey, T. B. Agricola Articles by Tian, X. Articles by Bailey, T. B. Related Collections Seed Quality Seed Physiology Seed Treatment

SEED PHYSIOLOGY, PRODUCTION & TECHNOLOGY

Response of Eastern Gamagrass Seed to Gibberellic Acid Buffered below Its pKa

^a Dep. of Agronomy, Iowa State Univ., Ames, IA 50011
^b Dep. of Statistics, Iowa State Univ., Ames, IA 50011

^* Corresponding author (adknapp{at}iastate.edu)

Eastern gamagrass [Tripsacum dactyloides (L.) L.] seed are usually dormant, often causing seedling establishment difficulties. This study was conducted to assess the effect of gibberellic acid (GA₃) buffered below its pKa (3.8) on seed germination of eastern gamagrass. In one experiment, concentrations of 0.001-, 0.005-, and 0.01 M buffered GA₃ solutions were applied to seed with cupules removed from six commercial seed lots produced in three different years. After 28 d of germination, GA₃ application increased total seed germination by 25 to 47 percentage points. The three GA₃ concentrations were equally effective in promoting germination in all seed lots except one, where 0.001 M GA₃ was more effective than 0.01 M GA₃. The germination rate was accelerated by GA₃ application during the germination process but did not result in germination of all the viable seeds. An average 10% of the viable caryopses remained dormant at the end of the germination test. A second experiment evaluated the germination of intact cupules after treatment for 24 or 48 h in distilled water, 0.001 M GA₃ solution, buffer solution, or buffered 0.001 M GA₃ solution. Buffered GA₃ was not effective at enhancing germination of eastern gamagrass seed when cupules were left intact. These results suggest that there may be multiple dormancy mechanisms in eastern gamagrass. At least one mechanism involves the caryopsis and is affected by GA₃ application. Furthermore, the cupule-mediated dormancy mechanism(s) and the caryopsis-mediated mechanism(s) must be addressed to obtain complete germination of dormant seed.

Abbreviations: TZ, 2,3,5-triphenyl tetrazolium chloride • GA, gibberellic acid

This article has been cited by other articles:

				L. R. Gibson, E. Z. Aberle, A. D. Knapp, K. J. Moore, and R. Hintz Release of Seed Dormancy in Field Plantings of Eastern Gamagrass Crop Sci., January 31, 2005; 45(2): 494 - 502. [Abstract] [Full Text] [PDF]

				C. Rogis, L. R. Gibson, A. D. Knapp, and R. Horton Enhancing Germination of Eastern Gamagrass Seed with Stratification and Gibberellic Acid Crop Sci., March 1, 2004; 44(2): 549 - 552. [Abstract] [Full Text] [PDF]