Genetic dissection of heterosis using epistatic association mapping in a partial NCII mating design

Wen, J., Zhao, X., Wu, G., Xiang, D., Liu, Q., Bu, S.-H., Yi, C., Song, Q., Dunwell, J. M. ORCID: https://orcid.org/0000-0003-2147-665X, Tu, J., Zhang, T. and Zhang, Y.-M. (2015) Genetic dissection of heterosis using epistatic association mapping in a partial NCII mating design. Scientific Reports, 5. 18376. ISSN 2045-2322 doi: 10.1038/srep18376

Abstract/Summary

Heterosis refers to the phenomenon in which an F1 hybrid exhibits enhanced growth or agronomic performance. However, previous theoretical studies on heterosis have been based on bi-parental segregating populations instead of F1 hybrids. To understand the genetic basis of heterosis, here we used a subset of F1 hybrids, named a partial North Carolina II design, to perform association mapping for dependent variables: original trait value, general combining ability (GCA), specific combining ability (SCA) and mid-parental heterosis (MPH). Our models jointly fitted all the additive, dominance and epistatic effects. The analyses resulted in several important findings: 1) Main components are additive and additive-by-additive effects for GCA and dominance-related effects for SCA and MPH, and additive-by-dominant effect for MPH was partly identified as additive effect; 2) the ranking of factors affecting heterosis was dominance > dominance-by-dominance > over-dominance > complete dominance; and 3) increasing the proportion of F1 hybrids in the population could significantly increase the power to detect dominance-related effects, and slightly reduce the power to detect additive and additive-by-additive effects. Analyses of cotton and rapeseed datasets showed that more additive-by-additive QTL were detected from GCA than from trait phenotype, and fewer QTL were from MPH than from other dependent variables.

Item Type	Article
URI	https://reading-pure-test.eprints-hosting.org/id/eprint/49598
Identification Number/DOI	10.1038/srep18376
Refereed	Yes
Divisions	Life Sciences > School of Agriculture, Policy and Development > Department of Crop Science Central Services
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