Abstract Detail

Crops and Wild Relatives

Welles, Shana [1], Sonnenschein, Anne [2].

Population genomic structure of the invasive crop-wild hybrid California wild radish along a climate gradient.

Hybridization between crops and their wild relatives commonly occurs in locations where they co-occur. This is a concern due to the potential for movement of crop genes, potentially including transgenes into wild populations. Hybridization between crops and wild relatives is also known to lead to the evolution of weedy invasive species. Multiple authors have argued that crop genes that crop genes will be maladaptive in wild populations, however there are multiple examples of persistence of crop genes in wild populations. One invasive species that has evolved via crop-wild hybridization is California wild radish, a hybrid between crop radish (Raphanus sativus) and jointed charlock (R. raphanistrum). California wild radish has been used as a model system to understand crop-wild hybridization. It is a weedy species present across California both along the coast and as a weed of agricultural systems. A previous study of artificial R. sativus x R. raphanistrum crosses demonstrated that across 3 molecular markers plus one single-locus trait crop genes were retained over multiple generations across multiple replicates. In this study, we investigate how population genetic structure and relatedness to crop radish vary in wild populations along a 1207 km climate gradient along the coast of California from Eureka to San Diego. We address these questions using whole genome resequencing followed by alignment and SNPs calls based using the R. sativus genome. In a weedy or invasive species that results from homoploid hybridization between a crop and a wild species the number of crop genes that are present in the resulting lineage will be affected by selection that favors or disfavors crop genes and neutral processes. Addressing these questions at the genome-wide scale in wild populations along a climate gradient allows us to better understand how homoploid wild-crop genomes evolve following hybridization and how this varies across space.

1 - Chapman University, SCST, One University Dr, Orange, CA, 92866, United States
2 - Chapman University, University Dr, Orange, CA, 92866, United States

Keywords:
hybridization
Raphanus
Invasion
Population genomics.

Presentation Type: Oral Paper
Session: CWR1, Crops and Wild Relatives
Location: Tucson D/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 8:15 AM
Number: CWR1002
Abstract ID:955
Candidate for Awards:None