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United States Department of Agriculture

Agricultural Research Service

Title: Studies on a Nondormant Sunflower Mutant

Authors
item Vick, Brady
item Cook, Leonard
item Jan, Chao-Chien

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: March 6, 2006
Publication Date: March 6, 2006
Citation: Vick, B.A., Cook, L.W., Jan, C.C. 2006. Studies on a nondormant sunflower mutant. 28th Sunflower Research Workshop, January 11-12, 2006, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Vick_Mutant_06.pdf

Interpretive Summary: During the course of greenhouse studies, an unexpected sunflower mutant resulting from an interspecific cross of the wild perennial Helianthus divaricatus with cultivated HA 89 was found. In this mutant, dormancy is not induced in the developing embryo. Instead, developing seeds of the mutant sunflower begin to germinate in the head about 40 days after pollination. We investigated the levels of abscisic acid, a known inducer of dormancy in many plants, in the developing seeds of the nondormant mutant at various stages after pollination. The abscisic acid content in the mutant seeds was about 25% lower than in the control line HA 89. In addition, when developing nondormant mutant embryos were placed on an agar medium containing 50 uM abscisic acid, dormancy was induced and the embryos did not germinate. These preliminary results suggest that there is insufficient abscisic acid signal available in the mutant at the proper time to induce dormancy. This information will be useful in understanding the process of dormancy in sunflower seeds.

Technical Abstract: An unexpected sunflower mutant resulting from an interspecific cross of the wild perennial Helianthus divaricatus with cultivated HA 89 was identified. In this mutant, dormancy is not induced in the developing embryo. Instead, developing seeds of the mutant sunflower begin to germinate in the head about 40 days after pollination. We investigated the levels of abscisic acid, a known inducer of dormancy in many plants, in the developing seeds of the nondormant mutant at various stages after pollination. The abscisic acid content in the mutant seeds was about 25% lower than in the control line HA 89. In addition, when developing nondormant mutant embryos were placed on an agar medium containing 50 uM abscisic acid, dormancy was induced and the embryos did not germinate. These preliminary results suggest that there is insufficient abscisic acid signal available in the mutant at the proper time to induce dormancy.

Last Modified: 7/28/2014
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