Selection for silage yield and composition did not affect genomic diversity within the Wisconsin Quality Synthetic maize population.
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.
Affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583 firstname.lastname@example.org.Show MeSH
Mentions: Despite no strong signatures of selection and marker-trait associations, an examination of D for each locus shows that reductions were not uniform across the genome (Figure 3). A large reduction in D was observed in regions on chromosomes 2 (∼132 million bp), 3 (∼55 million bp), and 4 (∼78 million bp). These regions of relatively greater loss in diversity were defined visually by examining the D plots in Figure 3. Average D across all loci was reduced from 0.352 in C2 to 0.285 in C5. Although average genome-wide D was only reduced by 19% from C2 to C5, average D in these regions on chromosomes 2, 3, and 4 was reduced by 62%, 79%, and 67%, respectively. The large region on chromosome 2, for example, had an average D of 0.355 in C2, which is very close to the average genome-wide D in C2. By C5, however, the average D was only 0.135, which is well below 1 SD of D (genome-wide SD = 0.131).
Affiliation: Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583 email@example.com.