ARS | Publication request: REGISTRATION OF TRICOT SUNFLOWER GENETIC STOCK

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2006
Publication Date: December 1, 2006
Citation: Hu, J., Miller, J.F., Vick, B.A. 2006. Registration of a tricotyledon sunflower genetic stock. Crop Science. 46:2734-2735.

Interpretive Summary: Seedlings with three cotyledons occur sporadically in nurseries of dicotyledonous plant species, including sunflower. Researchers have documented this phenomenon in many plant species such as tomato, mustards and snapdragon. In most cases, the tricot phenotypes did not produce pure tricotyledonous progeny and the inheritance seemed complex. A sunflower mutant with three cotyledons was found in a BC3F2 population. Results of progeny tests of three consecutive generations suggested that this trait is heritable since the frequency of tricotyledonous phenotype increased from approximately 2% in the F2 generation to about 50% in the F5 generation. This peculiar phenotype could be an interesting subject for basic developmental biology study. This plant type is potentially useful for faster establishment of seedlings after planting due to having a larger leaf area in early growing stages, and serving as a morphological characteristic to distinguish cultivars.

Technical Abstract: This paper registers a sunflower genetic stock, Tricot, with a tricotyledonous phenotype. The mutant was found in a BC3F2 population developed for incorporating sulfonylurea (SU) herbicide resistance into cultivated sunflower. Progeny tests of three consecutive generations under both greenhouse and field conditions during the past two years suggested that this trait is heritable since it was observed that the frequency of tricotyledonous phenotype increased from approximately 2% in the F2 generation to about 50% in the F5 generation. The tricotyledonous seedlings also produced true leaves in sets of three at the first few nodes. This peculiar phenotype could be an interesting subject for basic developmental biology study. This plant type is potentially useful for faster establishment of seedlings after planting due to having a larger leaf area in early growing stages, and serving as a morphological characteristic to distinguish cultivars.