Improvement of Seed Germination in Three Medicinal Plant Species by Plant Growth Regulators

Abstract

<jats:p>Peppermint (<jats:italic>Mentha piperita</jats:italic>), sweet basil (<jats:italic>Ocimum basilicum</jats:italic>), and coriander <jats:italic>(Coriandrum sativum</jats:italic>) are important medicinal plants in the pharmacological industry. These plants are produced in commercial scale but their seeds exhibit low germination percentages under favorable germination conditions. Enhancing seed germination is thus crucial for improving the production of these plants. The influence of gibberellic acid (GA<jats:sub>3</jats:sub>), indole-3-acetic acid (IAA), indol-3-butyric acid (IBA), and naphthalene acetic acid (NAA) on seed germination of the three plants were investigated. The seeds were soaked in each plant growth regulator at 50, 100, and 150 mg·L<jats:sup>−1</jats:sup> for 24 hours at 25 ± 2 °C. Seed germination was checked daily for 20 days and germination parameters including final germination percentage (FGP), corrected germination rate (CGRI), and number of days lapsed to reach 50% of FGP (GT<jats:sub>50</jats:sub>) were recorded. The phosphorus and protein contents were determined in germinated seedlings on day 21 of culture. All plant growth regulators enhanced seed germination as compared with control. However, GA<jats:sub>3</jats:sub> improved seed germination more than IAA, IBA, and NAA. GA<jats:sub>3</jats:sub> at 100 mg·L<jats:sup>−1</jats:sup> significantly increased the FGP from 22.3% and 33.3% (control) to 74% and 65.6% for peppermint and sweet basil, respectively. Low concentration of GA<jats:sub>3</jats:sub> at 50 mg·L<jats:sup>−1</jats:sup> increased the FGP for coriander from 27% to 52.3%. GA<jats:sub>3</jats:sub> also increased CGRI, GT<jats:sub>50</jats:sub>, phosphorus, and protein contents in germinated seedlings as compared with control. Seeds of peppermint, sweet basil, and coriander possess a physiological dormancy that could be elevated by GA<jats:sub>3</jats:sub> presowing treatment. This study established a successful methodology for optimizing seed germination to satisfy the demand for the medicinal parts of these plants in the pharmacological industry.</jats:p>

Use of ammonium salts or binary mixtures derived from amino acids, glycine betaine, choline and indole-3-butyric acid as plant regulators

“…This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.counterion or the second component of the binary mixture. Note that similar results have been reported for applying IBA to other plants to stimulate germination 53,54.…”

Germination of Pulsatilla Seeds as Influenced by Seed Morphology, Moist 5 °C and Gibberellin (GA3) Treatment, and Detection of Nickel in Seeds

“…Dormancy could be a factor for low germination rates and can be avoided by low-temperature treatments or plant growthregulating treatments, especially true with gibberellin treatment (Cadman et al, 2006;Elhindi et al, 2016) or abscisic acid that affects the sensitivity of GA and the ratios between abscisic and GA (Finch-Savage and Leubner-Metzger, 2006). The overall germination rate of P. turczaninovii was 48% to 52.6%; these rates were significantly lower than that of P. cernua, which was >92% with a GA 3 treatment for 24 h, compared with 18% in an untreated control (Gu et al, 2014).…”

Effects of Scarification, Phytohormones, Soil Type, and Warming on the Germination and/or Seedling Performance of Three Tamaulipan Thornscrub Forest Species

“…IBA treatment has also become commonplace but is typically used for clonal propagation or to stimulate root growth in transplants. However, recent studies show IBA can also promote germination [ 50 ] and may interact with GA in positive or synergistic ways [ 28 ]. The effects of IBA on germination of thornscrub species has not been studied.…”