Seed germination dynamics of silverleaf nightshade (Solanum elaeagnifolium Cav.) and implications for effective weed management

Abstract

Silverleaf nightshade (Solanum elaeagnifolium Cav.) is a noxious weed that threatens agricultural productivity and biodiversity worldwide. The long‐term management of soil seedbanks along with the aboveground populations of silverleaf nightshade has the potential to effectively control the species in its introduced range. Implementation of this strategy requires insights into the germination behavior of the weed in response to various environmental stimuli and endogenous cues. We assessed the morphology and germination of silverleaf nightshade seeds from an agricultural farm, native rangelands, and an urban site in Texas, USA. The effects of growth substrate, phytohormones, and salt treatments on seed germination were also evaluated to identify potential stimulus that can be used to manipulate germination in the species. Results of the study showed that silverleaf nightshade seeds from the agricultural farm were the largest, while those from the Littlefield rangeland were the smallest. Seeds collected from the urban site and agricultural farm have higher germination rates than those sampled from the rangelands. Compared to domesticated crops, silverleaf nightshade seeds require longer imbibition time. Seed germination was better in potting mix than in sand or combined potting mix and sand and was significantly reduced by salt and abscisic acid treatments. Overall, results of the study highlight the crucial role of local environments in conditioning the transgenerational adaptation of species, particularly with respect to germination. Recommendations for silverleaf nightshade control are presented based on the observed variations in the germination behavior of populations within specific ranges.

Early detection, herbicide resistance screening, and integrated management of invasive plant species: a review

“…The species is at dormancy during winter. Seed germination is favored under alternating temperatures over 20 °C, 23 while seed traits are strongly affected by the environment to which the plant is adapted 24 . It has spines in the stem and the flowers are purple, white or blue‐colored 25 .…”

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

“…Each growing season, an individual S. elaeagnifolium plant can produce in excess of 200 berries, each containing between 24 and 150 seeds (Boyd & Murray, 1982; Cuthbertson et al, 1976; Stanton et al, 2012; Utah, 2007). These seeds have been observed to vary in colour, shape and size between disconnected populations (e.g., agricultural fields, native rangelands and urban areas), and may be a result of different environmental factors such as light, nutrient availability and water, which may influence their development (Turner et al, 2021). These berries can also significantly aid in the long‐distance dispersal of S. elaeagnifolium seeds across the landscape as they can be spread via the process of animals (zoochory), human‐induced actions, water (hydrochory), and wind (anemochory) (Boyd & Murray, 1982; Cuthbertson et al, 1976; McKenzie, 1980).…”

“…The germination of S. elaeagnifolium seeds can occur in both light and dark conditions (Stanton et al, 2009), although this process requires diurnally fluctuating temperatures, a feature which has also been observed in several Solanum species (Boyd & Murray, 1982; Stanton et al, 2012). Solanum elaeagnifolium seeds are also required to be broken from physical dormancy before germination, which can be alleviated by alternating diurnal temperatures, chemical scarification or prolonged water immersion (Rutherford, 1978; Stanton et al, 2012; Turner et al, 2021). An ex situ study on S. elaeagnifolium in Texas found that seed germination is reduced when exposed to abscisic acid and salt treatments (Turner et al, 2021).…”

“…Solanum elaeagnifolium seeds are also required to be broken from physical dormancy before germination, which can be alleviated by alternating diurnal temperatures, chemical scarification or prolonged water immersion (Rutherford, 1978; Stanton et al, 2012; Turner et al, 2021). An ex situ study on S. elaeagnifolium in Texas found that seed germination is reduced when exposed to abscisic acid and salt treatments (Turner et al, 2021). In this latter respect, the germination of the species is limited to regions or periods when ample water supplies are readily available.…”

“…In this latter respect, the germination of the species is limited to regions or periods when ample water supplies are readily available. Studies have shown that S. elaeagnifolium seeds can remain viable for up to 10 years within the soil and often require longer imbibition times compared with surrounding domesticated crops, which is likely to increase at greater depths (Brunel, 2011; Stanton et al, 2012; Turner et al, 2021). In this regard, long‐term management of infested areas is often required.…”