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Selection for silage yield and composition did not affect genomic diversity within the Wisconsin Quality Synthetic maize population.

Lorenz AJ, Beissinger TM, Silva RR, de Leon N - G3 (Bethesda) (2015)

Bottom Line: The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population.Variation in loss of diversity through drift was observed across the genome.Some large regions experienced much greater loss in diversity than what is expected, suggesting limited recombination combined with small populations in recurrent selection programs could easily lead to fixation of large swaths of the genome.

View Article: PubMed Central - PubMed

Affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583 alorenz2@unl.edu.

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Schematic of the selection protocol utilized to advance the Wisconsin Quality Synthetic (WQS) population. A second generation (S2) topcross selection method is utilized to improve this germplasm. Inbreds derived from succeeding cycles of improvement are developed and released. Population improvement and inbred development occur simultaneously. The red oval highlights the approximately the 20 S2 families that originate each subsequent cycle of selection.
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fig1: Schematic of the selection protocol utilized to advance the Wisconsin Quality Synthetic (WQS) population. A second generation (S2) topcross selection method is utilized to improve this germplasm. Inbreds derived from succeeding cycles of improvement are developed and released. Population improvement and inbred development occur simultaneously. The red oval highlights the approximately the 20 S2 families that originate each subsequent cycle of selection.

Mentions: Details on the formation of WQS can be found in Frey et al. (2004) and Gustafson et al. (2010). The breeding protocol utilized to advance WQS is depicted in Figure 1. Briefly, for cycles zero through three, between 400 and 500 S1 families of WQS were initially screened for general agronomic suitability in a high-plant-density replicated trial in South Central Wisconsin. The same S1 families were simultaneously self-pollinated in the breeding nursery. Approximately 50% to 67% of the S1 families were discarded based on the stress trial. During the following season, S1:2 families descended from random plants within selected S1 families are crossed to testers belonging to the Stiff Stalk heterotic group. Resulting topcross hybrids are evaluated at two locations the following summer. Evaluations used standard field plot techniques for silage hybrids to estimate forage yield and composition (Frey et al. 2004; Gustafson et al. 2010).


Selection for silage yield and composition did not affect genomic diversity within the Wisconsin Quality Synthetic maize population.

Lorenz AJ, Beissinger TM, Silva RR, de Leon N - G3 (Bethesda) (2015)

Schematic of the selection protocol utilized to advance the Wisconsin Quality Synthetic (WQS) population. A second generation (S2) topcross selection method is utilized to improve this germplasm. Inbreds derived from succeeding cycles of improvement are developed and released. Population improvement and inbred development occur simultaneously. The red oval highlights the approximately the 20 S2 families that originate each subsequent cycle of selection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390570&req=5

fig1: Schematic of the selection protocol utilized to advance the Wisconsin Quality Synthetic (WQS) population. A second generation (S2) topcross selection method is utilized to improve this germplasm. Inbreds derived from succeeding cycles of improvement are developed and released. Population improvement and inbred development occur simultaneously. The red oval highlights the approximately the 20 S2 families that originate each subsequent cycle of selection.
Mentions: Details on the formation of WQS can be found in Frey et al. (2004) and Gustafson et al. (2010). The breeding protocol utilized to advance WQS is depicted in Figure 1. Briefly, for cycles zero through three, between 400 and 500 S1 families of WQS were initially screened for general agronomic suitability in a high-plant-density replicated trial in South Central Wisconsin. The same S1 families were simultaneously self-pollinated in the breeding nursery. Approximately 50% to 67% of the S1 families were discarded based on the stress trial. During the following season, S1:2 families descended from random plants within selected S1 families are crossed to testers belonging to the Stiff Stalk heterotic group. Resulting topcross hybrids are evaluated at two locations the following summer. Evaluations used standard field plot techniques for silage hybrids to estimate forage yield and composition (Frey et al. 2004; Gustafson et al. 2010).

Bottom Line: The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population.Variation in loss of diversity through drift was observed across the genome.Some large regions experienced much greater loss in diversity than what is expected, suggesting limited recombination combined with small populations in recurrent selection programs could easily lead to fixation of large swaths of the genome.

View Article: PubMed Central - PubMed

Affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583 alorenz2@unl.edu.

Show MeSH