Aqueous Leaf Extract of Duranta repens Promotes Seed Germination and Seedling Growth of Salinity-Stressed Solanum lycopersicum Seedlings.

Abstract

Aqueous extract of Duranta repens leaves was investigated for its allelopathic effect on Solanum lycopersicum seedlings germinated and grown under salinity condition. The study was carried out using both laboratory petridish and pot assays to simulate the plant’s immediate environmental conditions. The experiment consisted of 5 groups (1-5) each containing 4 replicates (of 10 seeds). Group 1 was treated with distilled water; Group 2 was treated with 5 mM NaCl; Group 3 was treated with Duranta repens aqueous leaf extract, Group 4 was treated with a mixture of 5 mM NaCl and the extract (2:1 v/v) and Group 5 was treated with a mixture of 5 mM NaCl and the extract (1:2 v/v). Results from the studies revealed that treatment with NaCl caused significant (p < 0.05) reduction in percentage germination and growth parameters (plumule and radicle lengths) of S. lycopersicum seedlings, when compared to those treated with distilled water and D. rupens aqueous leaf extract. NaCl treatment (Group 2) also caused an increase in malondialdehyde (MDA) and also increased the activities of superoxide dismutase (SOD) and catalase (CAT) while reducing chlorophyll concentration of the plants. However, in the presence of the extract, the adverse effects of the NaCl were attenuated, implying that the extract improved tolerance of S. lycopersicum seedlings. In conclusion, the findings of this study indicate that the constituents of the extract may play a positive role in plant survival under saline conditions and could be employed in the management of soil salinity problem in agriculture. Keywords: Duranta repens; Solanum lycopersicum; Salinity Stress; Allelopathy; Aqueous Extract