Effects of different treatments on seed germination and breaking seed dormancy of Citrullus colocynthis an endangered medicinal plant

Abstract

Citrullus colocynthis plants often have a longer period of dormancy because of the strong seed coat. To reduce the dormancy period and improve seed germination, in the present study we evaluated the significant effects of external conditions including temperature, light and humidity under in vitro conditions. The seeds are treated with acid and boiling water for different time intervals. 50% decorticated seeds were obtained by removing the lignified outer coats from the seeds. Intact embryos and decocted seeds were selected and separated directly into half-strength MS medium, paper boats in culture tubes, Petri dishes covered with Whatman No. 1 filter paper, and solid-strength MS medium covered with nylon mesh In all treatments, the mechanical approach is ideal for breaking seed dormancy in C. colocynthis. The scarification technique results in 92% of seeds germination, compared to 43% and 56% for the remaining acid and hot water treatments respectively. Present research methods help to break and overcome seed dormancy in plants with hard seed coats.