The effect of Cymbopogon citratus aqueous leaf extract on Solanum lycopersicum seed germination and seedling growth under saline conditions

Abstract

The allelopathic potential of Cymbopogon citratus aqueous leaf extract on the germination of Solanum lycopersicum seeds under saline conditions was investigated in a laboratory bioassay. At the end of the eight-day trial, the seeds were evaluated for germination parameters and antioxidant enzyme activities. Under the saline condition, the extract enhanced germination of S. lycopersicum seeds. Furthermore, there was a reduction in the plumule and radicle lengths of S. lycopersicum seeds following exposure to NaCl, which were significantly improved (p < 0.05) in the presence of the extract. Findings further revealed that salinity caused an increase in malondialdehyde concentration, while lowering the activities of peroxidase, polyphenol oxidase, superoxide dismutase and catalase in S. lycopersicum seedlings. The aqueous leaf extract of C. citratus reversed this situation, which implied that the extract improved the salinity tolerance of S. lycopersicum seeds. Overall, the findings of the present study indicate that the extract may play a positive role in seed germination under saline conditions.

Keywords:

• allelopathy
• antioxidant enzymes
• sseed germination
• soil salinity