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United States Department of Agriculture

Agricultural Research Service

Title: Genetic Mapping Forage Yield, Plant Height, and Regrowth at Multiple Harvests in Tetraploid Alfalfa (Medicago Sativa L.)

Authors
item Robins, Joseph
item Bauchan, Gary
item Brummer, E - IOWA ST. UNIV.

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 31, 2006
Publication Date: January 22, 2007
Citation: Robins, J.G., G.R. Bauchan, and E.C. Brummer. 2007. Genetic mapping forage yield, plant height, and regrowth at multiple harvests in tetraploid alfalfa (Medicago sativa L.). Crop Sci. 47:11-18.

Interpretive Summary: Crosses between Medicago sativa subspecies falcata and sativa result in high levels of heterosis for alfalfa forage production. However, desirable alfalfa cultivars must have acceptable performance for other agronomic traits including regrowth following harvest and appropriate autumn dormancy. In this study, an F1 population derived from the cross of the two subspecies was used to characterize the genetics of forage production, forage height, and forage regrowth. Quantitative trait loci (QTL) controlling these traits were mapped on genetic linkage maps developed from this population. QTL results identified associated alleles contributed by each parental genome suggesting that both subspecies of cultivated alfalfa may contribute to the improvement of these traits. Broad-sense heritabilities were high for each of the traits indicating the importance of genetic as compared to environmental effects on these traits. Genetic correlations between each of the traits were also high suggesting common genetic determinants for each of the traits. A subset of alleles associated with more than one of the traits indicated common genetic determinants for the traits and supported the high genetic correlations among the traits.

Technical Abstract: Crosses between Medicago sativa subspecies falcata and sativa result in high levels of heterosis for alfalfa forage production. However, desirable alfalfa cultivars must have acceptable performance for other agronomic traits including regrowth following harvest and appropriate autumn dormancy. In this study, an F1 population derived from the cross of the two subspecies was used to characterize the genetics of forage production, forage height, and forage regrowth. Quantitative trait loci (QTL) controlling these traits were mapped on genetic linkage maps developed from this population. QTL results identifed associated alleles contributed by each parental genome suggesting that both subspecies of cultivated alfalfa may contribute to the improvement of these traits. Broad-sense heritabilities were high for each of the traits indicating the importance of genetic as compared to environmental effects on these traits. Genetic correlations between each of the traits were also high suggesting common genetic determinants for each of the traits. A subset of alleles associated with more than one of the traits indicated common genetic determinants for the traits and supported the high genetic correlations among the traits.

Last Modified: 8/22/2014
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