Investigating Nicotine’s Role in In vitro Seed Germination and Seedling Growth of Tomato

Abstract

Nicotine is an addictive alkaloid found primarily in tobacco plants. Nicotine can be leached out into the soil through discarded tobacco products and can be taken up through the roots of plants and accumulated within them. Tomato (Solanum lycopersicum) is one of the major crops in the world that also contributes to the Sri Lankan economy. To study the effect of nicotine on plant growth and development, crude nicotine was extracted from dried tobacco leaves using the solvent extraction method. The study was conducted in vitro conditions. Tomato seeds were exposed to 20 μL/L, 50 μL/L, 100 μL/L, and 200 μL/L of crude nicotine (CN) in two types of media (media supplemented with 0.1 mg/L IAA and 2 mg/L BAP, and the other media without hormones). The seed germination rate and the growth and development of the seedlings were observed over a period of 8 weeks. The seed sprouting rate was highest in 100 μL/L CN in the media supplemented with hormones. The seed sprouting rate was highest in 50 μL/L CN in the hormone-free media. In the hormone-supplemented media, CN inhibited the growth of seedlings, especially in the 200 μL/L CN, where even the root growth was severely stunted. In the hormone-free media, some seedlings that were exposed to CN showed nutrient deficiency symptoms, and adventitious roots were observed coming from the leaves of some seedlings. This study provides insight into how nicotine from tobacco and nicotine products can affect seed germination and seedling growth.