Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Thrash, Tyler [1], Lee, Hansol [2], Baker, Robert L. [3].

Quantitative Trait Loci for Constraining Models of Resource Allocation in Brassica rapa.

As a result of global climate change, crops in some agricultural areas are expected to receive less precipitation and experience higher temperatures and may thus require supplemental irrigation. Because irrigation can increase the concentration of soil salinity, resilience to salt stress is an increasingly important characteristic for crop improvement. The ideal stress response of B. rapa varies across agricultural areas because different cultivars are bred to preferentially allocate resources to different plant parts. Some varieties of B. rapa are grown for their oil seeds, while other varieties are grown for their large edible leaves. As a first step towards improving stress-resistant crops with these different varieties in mind, we investigated the genetic architecture underlying resource allocation in response to soil salinity. Towards this end, we conducted a greenhouse experiment with 188 B. rapa Recombinant Inbred Lines (RILs) that were watered with either tap water or water containing a low concentration of salt throughout plant development. Throughout the experiment, we measured stem length and number of attached leaves. Before destructively sampling the plants at multiple developmental phases, we also counted the final number of vegetative and reproductive nodes. These observed phenotypes were then used to construct phenotypic ratios that represented different possible solutions to resource allocation problems. We mapped Quantitative Trait Loci (QTLs) for these phenotypic ratios and their constituent measures in order to constrain models that may explain resource allocation in terms of genetic linkage and pleiotropy. Specifically, we found significant interactions between treatment (salt versus control) and developmental phase for different phenotypic ratios and their constituent measures. Together, these interactions suggest that, late in development, plants exposed to salt water were more likely to prioritize vegetative growth over reproductive fitness compared to control plants with the same genotype. In addition, we identified several QTL related to these phenotypic ratios that were consistent across control and salt treatments. By further constraining models of resource allocation in B. rapa, these results can inform the improvement of different cultivars in terms of salt-stress responses.

1 - Miami University, Biology, 700 E High Street, PSN 334, Oxford, OH, 45056, United States
2 - Miami University, Biology, 700 E High Street, PSN 334, Oxford, OH, 45056, USA
3 - Miami University, Biology, 700 E High Street, PSN 390, Oxford, OH, 45056, USA

Salt stress
quantitative trait loci.

Presentation Type: Poster
Session: P, Evolutionary Developmental Biology (Evo-Devo) Posters
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 5:00 PM Time and date to be determined
Number: PEV011
Abstract ID:484
Candidate for Awards:None

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