Biology subjects

Raduski, A. R.

Publications and source records attributed to Raduski, A. R..

3 recordsLinked to original sources

bioRxiv2021

Development of first linkage map for Silphium integrifolium (Asteraceae) enables identification of sporophytic self-incompatibility locus

O_LISilphium integrifolium (Asteraceae) has been identified as a candidate for domestication as a perennial oilseed crop and has a sporophytic self-incompatibility system--the genetic basis of which is not well understood in the Asteraceae. To address this gap, we sought to map the genomic location of the self-recognition locus (S-locus) in this species. C_LIO_LIWe used a biparental population and genotyping-by-sequencing to create the first genetic linkage map for this species. Then we developed a novel crossing scheme and set of analysis methods in order to infer S-locus genotypes for a subset of these individuals, allowing us to map the trait. Finally, we identified potential gene candidates using synteny analysis with the annual sunflower (Helianthus annuus) genome. C_LIO_LIOur linkage map contains 198 SNP markers and resolved into the correct number of linkage groups. We were able to successfully map the S-locus and identify several potential gene candidates in the sunflower syntenic region. C_LIO_LIOur method is effective and efficient, allowed us to map the S. integrifolium S-locus using fewer resources than previous studies, and could be readily be applied to other species. Our best gene candidate appears to be worthy of future work in S. integrifolium and other Asteraceae species. C_LI

plant biology↗

bioRxiv2020

Patterns of genetic variation in a prairie wildflower, Silphium integrifolium, suggest a non-prairie origin and untapped variation available for improved breeding.

AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSPremiseC_ST_ABSUnderstanding the relationship between genetic structure and geography provides information about a species evolutionary history and can be useful to breeders interested in de novo domestication. The North American prairie is especially interesting because of its relatively recent origin and subsequent dramatic fragmentation and degradation. Silphium integrifolium is an iconic perennial American prairie wildflower targeted for domestication as an oilseed crop. Germplasm in the existing breeding program is derived from accessions collected in restricted geographic regions. We present the first application of population genetic data in this species to address the following goals (1) improve breeding programs by characterizing genetic structure and (2) identify the species geographic origin and potential targets and drivers of selection during range expansion. MethodsWe developed a reference transcriptome as a genotyping reference for samples from throughout the species range. Population genetic analyses were used to describe the distribution of genetic variation and demographic modeling was used to characterize potential processes that shaped variation. Outlier scans for selection and associations with environmental variables were used to identify loci linked to putative targets and drivers of selection. Key resultsGenetic variation partitions samples into three geographic clusters. Patterns of variation and demographic modeling suggest that the species origin is in the American southeast. Breeding program accessions are from the region with lowest observed genetic variation. ConclusionsThis iconic prairie species did not originate within the modern prairie. Breeding programs can be improved by including accessions from outside of the germplasm founding region, which has relatively little variation. The geographic structuring coupled with the identified targets and drivers of adaptation can guide collecting efforts towards populations with beneficial agronomic traits.

evolutionary biology↗

bioRxiv2020

Biosystematic Studies on the Status of Solanum chilense (Dunal) Reiche

AO_SCPLOWBSTRACTC_SCPLOWO_LIMembers of Solanum sect. Lycopersicum are commonly used as a source of exotic germplasm for improvement of the cultivated tomato, and are increasingly employed in basic research. Although it experienced significant early and ongoing work, the taxonomic status of many wild species in this section has undergone a number of significant revisions, and remains uncertain. C_LIO_LIHere, we examine the taxonomic status of obligately outcrossing Chilean wild tomato (Solanum chilense) using reduced-representation sequencing (RAD-seq), a range of phylogenetic and population genetic analyses, crossing data, and morphological data. C_LIO_LIOverall, each of our analyses provides some weight of evidence that the Pacific coastal populations and Andean inland populations of the currently described S. chilense represent separately evolving populations. C_LIO_LIDespite its vast economic importance, Solanum sect. Lycopersicon still exhibits considerable taxonomic instability. A pattern of under-recognition of outcrossing species may be common across flowering plants. We discuss the possible causes and implications of this observation, with a focus on macroevolutionary inference. C_LI

evolutionary biology↗