Cross-species transferability of Solanum spp. DNA markers and their application in assessing genetic variation in silverleaf nightshade (Solanum elaeagnifolium) populations from Texas, USA

Abstract

Silverleaf nightshade (Solanum elaeagnifolium Cav.) is an invasive species that has successfully spread outside its native range to become a noxious weed in 21 states in the United States and 42 countries worldwide. The successful establishment of S. elaeagnifolium outside its native habitat indicates its innate ability to adapt to a multitude of environments. Phenotypic plasticity and/or genetic adaptation have been identified as key mechanisms underlying the adaptive success of invasive species. Whereas phenotypic plasticity allows a species to buffer changes in the environment by altering its phenotypic attributes within the short term, genetic adaptation is responsible for the longer-term adaptability of plants to heterogeneous environments and is dependent on the amount of genetic variation present in the species. In this study, we screened DNA markers that are specific to tomato (Solanum lycopersicum L.) and Solanum lycopersicoides Dunal for their interspecific transferability to S. elaeagnifolium and determined the applicability of the transferable DNA markers in assessing the extent of genetic variation in populations from Lubbock, Littlefield, and Blackwell, TX. Of the 187 markers screened, 78 successfully amplified targets in S. elaeagnifolium, indicating the evolutionary conservation of marker loci across S. lycopersicum, S. lycopersicoides, and S. elaeagnifolium, despite their genetic divergence millions of years ago. Genotyping of S. elaeagnifolium populations using 50 DNA markers that consistently amplified clear bands in more than 60% of the plants identified nine polymorphic markers with 0.014 to 0.621 polymorphism information content. Genetic diversity analysis by DNA marker profiling established genetic variation among populations and within individuals of different populations. Unweighted paired group method with arithmetic mean analysis grouped the plants into six clusters that are generally defined by selection pressures unique to each collection site. Results of the study indicate the capacity of S. elaeagnifolium for genetic differentiation in response to variable selection pressures within the same geographic region.

Transferability of Microsatellite Markers Developed in Oenothera spp. to the Invasive Species Oenothera drummondii Hook. (Onagraceae)

“…There is a potential loss of loci in each step, and the final working set of primers is a small fraction of the original number [64,65]. Even when nearly all tested markers amplify the target regions, the number of identified polymorphic loci remains low [66,67]. The results may vary depending on the target organism, the number of markers tested, and the phylogenetic relationship between the source and the target species [63,68].…”

Development of a PCR-based, genetic marker resource for the tomato-like nightshade relative, Solanum lycopersicoides using whole genome sequence analysis

“…In fact, a subset of 54 S. lycopersicoides-specific, indel markers have been successfully used to assess the genetic diversity in silverleaf nightshade populations from different localities in Texas, USA. Genetic profiling using the indels, along with other DNA markers from related species, established the genetic differentiation of silverleaf nightshade populations in response to variations in selection pressures that are unique to the ecological habitats selected in the study [62].…”

Biology, distribution and management of the globally invasive weed Solanum elaeagnifolium Cav (silverleaf nightshade): A global review of current and future management challenges

“…Previous management attempts on S. elaeagnifolium have shown varying success which can be explained due to its high ecological tolerance, prolific seed production and ability to reproduce via asexual propagation through root fragmentation (Mekki, 2007; Zhu et al, 2012). In addition, researchers have also identified that several spatially varied S. elaeagnifolium populations have displayed distinct morphological variation in their growth patterns, leaf structure and flowering, which suggests that genetic variation may be highly variable in the species (Petanidou et al, 2018; Qasem et al, 2019; Singleton et al, 2020; Zhu et al, 2012). In fact, recent molecular studies on S. elaeagnifolium have even shown high genetic variability within the same population and region (Petanidou et al, 2018; Singleton et al, 2020).…”