Author
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Kindiger, Bryan |
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Submitted to: Grassland Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/13/2015 Publication Date: 4/20/2015 Citation: Kindiger, B.K. 2015. Frequency of androgenesis in poa arachnifera x p. ligularis and p. poiformis hybridizations. Grassland Science. doi:10.1111/grs.12090. Interpretive Summary: Bluegrass represents a cool-season of turf and forage grass that comprises at least 500 species worldwide. Texas bluegrass is an indigenous cool-season perennial grass species native to Oklahoma, Texas and Kansas, USA. Earlier investigations in hybridizations between Texas bluegrass and Sandberg bluegrass, also a native USA bluegrass species, indicated that some offspring generated from the cross produce individuals possessing only Sandberg bluegrass characteristics. Chromosome and genetic studies indicated that Texas bluegrass will produce Sandberg bluegrass recoveries possessing reduced chromosome numbers with a complete loss of the Texas bluegrass chromosomes. Such recovered offspring are known as dihaploids. Though this behavior was documented in Texas bluegrass x Sandberg bluegrass crosses, no research on this behavior has been characterized to occur in hybrids between Texas bluegrass and other bluegrass species from other regions of the world. This research outlines the frequency of dihaploid generation in such hybridizations from crosses between Texas bluegrass and two additional bluegrass species, blue tussock grass, a native bluegrass of Australia, and Argentine meadow grass, a native bluegrass species of Argentina. Results of the research suggest this behavior also occurs in these hybridizations suggesting this behavior is typical of Texas bluegrass and can be anticipated to occur at various levels across other bluegrass species. Technical Abstract: The rapid generation of haploids in most species remains a relatively infrequent event, but is considered an important tool for the development of homozygous lines and an approach for cytoplasmic transfer across related species. Poa arachnifera (Texas bluegrass) is known to occasionally produce androgenic haploid recoveries following hybridization with Poa secunda. However, little information regarding the frequency of such behavior following hybridization with other Poa species is available. This study was undertaken to determine the frequency of androgenic haploid generation following interspecific hybridization of Poa arachnifera x P. ligularis and P. arachnifera x P. poiformis. The P. arachnifera x P. ligularis hybridizations exhibited a frequency of ADHs (ADH) at 0.997%; where the P. arachnifera x P. poiformis hybridizations indicated a frequency of 0.694%. Results from this study suggest the generation of androgenic dihaploids is an infrequent but consistent behavior likely found in sexual P. arachnifera. |
