Submitted to: Plant and Animal Genome Conference
Publication Type: Proceedings
Publication Acceptance Date: 11/24/2007
Publication Date: 1/10/2009
Citation: Kindiger, B.K., Wipff, J. 2009. Frequency of androgenesis in Poa arachnifera interspecific hybridizations. In: Proceedings of Plant and Animal Genome Conference, January 10-14, 2009, San Diego, CA. p. 200-205. Interpretive Summary: The generation of genetic diversity in bluegrass cultivars having commercial and economic importance is limited due to a non-sexual form of reproduction known as apomixis. Bluegrass cultivars possessing an apomictic form of reproduction only produce offspring that are exact genetic duplicates or clones of the maternal parent. Though apomixis is an advantage in the maintenance of seed or varietal purity, this reproductive behavior severely restricts the bluegrass breeder’s ability to expand the genetic diversity of his breeding stock. The generation of hybrids between Texas bluegrass x Kentucky bluegrass, Texas bluegrass x Big bluegrass; and Texas bluegrass x Argentine bluegrass were investigated to determine the potential of identifying an approach that could be utilized to increase a breeders potential for generating genetic diversity in bluegrass materials possessing an apomictic form of reproduction. Results of the study indicate that a rare occurring reproductive process in Texas bluegrass can be used as a tool to expand the genetic diversity of apomictic Poa. Though this reproductive attribute of Texas bluegrass is infrequent in occurrence, the unique offspring generated from the behavior are easy to identify through visual field evaluations or the use of DNA marker technologies. This information will be of interest to bluegrass breeders wanting to expand or diversify the genetic resources of their breeding programs.
Technical Abstract: The generation of haploids is a relatively infrequent event in most plant species. The derivation of paternal haploids via androgenesis has traditionally been used for the generation of inbred lines, transfer of cytoplasm, and genome reduction in polyploid species. This study investigates the use of a novel breeding approach that takes advantage of androgenenic behavior in Poa arachnifera and the subsequent generation of paternal dihaploid individuals. An interspecific hybridization program, utilizing non-apomictic, Poa arachnifera (Texas bluegrass) as the maternal parent in crosses with apomictic P. pratensis (Kentucky bluegrass), apomictic P. secunda (Big bluegrass) and non-apomictic P. ligularis (Argentine bluegrass), was investigated to determine the value of an androgenic-gamete selection breeding approach. Results of the study indicate that each of the interspecific hybridizations provided fertile, dihaploid individuals. The integration of molecular markers was also observed to complement the traditional breeding approach by enhancing the identification and selection of the dihaploid individuals.