Role of genetic diversity in the adaptive success of silverleaf nightshade (Solanum elaeagnifolium) under variable environmental pressures

The genetic diversity present within a plant population is a critical indicator of its capacity for adaptation to environmental variation and change. Solanum elaeagnifolium Cav (silverleaf nightshade; SLN) is an aggressive, highly persistent weed infesting agricultural croplands and rangelands in the US and abroad. The widespread geographical distribution of silverleaf nightshade indicates the presence of genetic mechanisms underlying fitness flexibility that allows the species to adapt to variable ecological niches. Based on DNA marker profiling and structure analysis, we were able to establish a significant degree of variation within all four of the tested SLN populations from different localities in Texas. We suggest from our study that the intracluster genetic variation found between the examined plant populations is entirely the product of obligate outcrossing that has resulted in an innate degree of variability. A simulation of a hypothetical development of herbicide resistance in silverleaf nightshade would be a significant resource to utilize, assess, and reference to design early onset preventive measures as opposed to in-response mitigation measures. The EDYS Simulation Model was used to conduct five independent scenarios to observe the simulated outcomes of differential herbicide control rates. The simulated herbicide resistance control rate of 75% reached a point of no recovery in biomass production in response to persistent annual herbicide control, while the herbicide resistance control rate of 50% and 25% showed both recovery and further growth. The results indicate that there is a threshold at which the value of resistance leads to either the species population dying off or recovering.