Chemical composition and allelopathic potential of the invasive plant Solanum rostratum Dunal essential oil

Abstract

The chemical profile and phytotoxicity of the essential oil (EO) extracted from the invasive weed Solanum rostratum Dunal was investigated. GC/MS analysis led to the identification of 29 constituents, with phytol, cholesterol trimethylsilyl ether, adipic acid, bis (2-ethylhexyl) ester, and muurola-4, 10(14)‑dien‑1β-ol being abundant in the oil. Phytotoxic assay showed that the EO exhibited significant suppressive action on seed germination and seedling development of test species. Starting from 0.5 mg/mL, seed germination of test plants was significantly affected, and when the concentration reached 5 mg/mL, the EO inhibited seed germination of Poa annua, Amaranthus retroflexus and Medicago sativa by 46.78%, 93.20% and 39.22%, respectively. The EO started to affect root elongation of P. annua, M. sativa and A. retroflexus at 0.5 mg/mL by 12.12%, 18.47% and 44.63%, respectively. At the highest concentration tested, 5 mg/mL, seed germination of A. retroflexus was completely prohibited, whereas the inhibition rate of P. annua and M. sativa were 55.25% and 51.59%, respectively. Our study is the first on the chemical profile and allelopathic potential of S. rostratum EO. Combining the low yield and relatively weak activity of S. rostratum EO, we thus concluded that it is unlikely that volatile allelochemical contribute significantly to the invasion success of S. rostratum.