Location: Forage and Livestock Production Unit
Title: Utilizing a dihaploid-gamete selection strategy for tall fescue development Author
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: October 25, 2012
Publication Date: November 16, 2012
Citation: Kindiger, B.K. 2012. Utilizing a dihaploid-gamete selection strategy for tall fescue development. In: Acquaah, G., editor. Principles of Plant Genetics and Breeding. 2nd edition. Chichester, UK:Wiley-Blackwell. p. 312-318. Interpretive Summary: Successful early generation selection during the process of plant breeding is essential for the development of superior cultivars. Gamete selection, that being, selection based on a single gamete or contribution from a pollen grain, represents a well known, but underutilized selection approach. Its application can only be applied to species where and when chromosome or genome loss can occur and results in the generation of individuals possessing only half the genetic contribution from either its female or male parents. In addition, a method to double the remaining chromosome set to generate a pure breeding line, also called an inbred line, is necessary. This report presents the application of a gamete selection approach for tall fescue that is based on the identification of inbred lines obtained from hybridization with unique ryegrass lines. The approach is rapid and efficient and can generate a wide range of new tall fescue germplasm in a very short time frame when compared to traditional tall fescue breeding approaches. These results and potential outcomes of this research will be of interest to academic and commercial entities involved in various facets of tall fescue or ryegrass research.
Technical Abstract: Gamete selection as originally defined by Stadler is based on the principal that selection exerted at the gametophytic level can increase desirable allelic frequencies detectable at the sporophytic level. If superior gametes can be recognized with certainty through a selection cycle, then such a system would be theoretically more efficient than one based on zygotic selection. Gamete selection ordinarily involves two steps: 1) selection on the basis of outcross performance testing of individual plants of a variety or population; and 2) a similar controlled selection for outstanding individuals exhibiting desirable agronomic attributes. The importance of a gamete form of selection, utilized during early generation selection, has been demonstrated to be successful in the selection for quantitative trait loci governing characteristics such as seed yield, maturity, and tolerance to disease. The application of a gamete selection will be more efficient and effective in developing superior tall fescue cultivars when compared to traditional recurrent selection techniques.