Abstract Detail

Functional Genetics/Genomics

Thrash, Tyler [1], Lee, Hansol [2], Gerbitz, Ryan [2], Kozyra, Abigail [2], Baker, Robert L. [2].

Epistatic interactions underlying abiotic stress response influence resource allocation in Brassica rapa.

Genotype-phenotype relationships are often characterized as one-to-one relationships, and Mendelian genetics is typically focused on the extent to which individual loci are related to particular traits. However, according to research in quantitative genetics, phenotypes can be controlled by more than one locus (i.e., polygenic), multiple phenotypes can be controlled by the same locus (i.e., pleiotropy), and multiple phenotypes may be inheritable together albeit controlled by different loci (i.e., genetic linkage). Furthermore, genetic loci can interact in a non-additive manner to affect a particular phenotype (i.e., epistasis). These aspects of genetic architecture complicate our basic understanding of evolution and adaptation and open up new possibilities for crop improvement. For example, the same locus may interact with other loci that control different traits related to the allocation of resources towards reproductive over vegetative growth. The present study examines the role of epistasis in resource allocation by Brassica rapa in response to abiotic stress. Specifically, we conducted a greenhouse experiment with 188 Recombinant Inbred Lines (RILs) that were watered with either tap water or water containing a low concentration of salt throughout development. Throughout the experiment, we measured several phenotypic traits and used them to construct resource allocation ratios. Higher values for each of these ratios indicated that the plant prioritized reproductive over vegetative growth. We also mapped these resource allocation ratios to coarse Quantitative Trait Loci (QTLs) as part of a more fine-grained Genome-Wide Association Study (GWAS). While the GWAS approach allowed us to identify more specific loci related to particular traits, QTL mapping provides a framework to assess complex aspects of genetic architecture such as epistasis. Indeed, the QTL analyses revealed an epistatic interaction for each resource allocation ratio with a common locus on chromosome 1. GWAS analyses will be used to search for evidence regarding the importance of this region for resource allocation as a result of abiotic stress.

1 - Miami University, Biology, 700 E High Street, PSN 212, Oxford, OH, 45056, USA
2 - Miami University, Biology, 700 E High Street, PSN 212, Oxford, OH, 45056, United States

Keywords:
Brassicaceae
quantitative genetics
epistasis
resource allocation.

Presentation Type: Oral Paper
Session: FG, Functional Genetics and Genomics
Location: /
Date: Monday, July 19th, 2021
Time: 10:00 AM(EDT)
Number: FG001
Abstract ID:536
Candidate for Awards:Margaret Menzel Award