Introducing Gamborg’s B5, a high-potential medium for isolated microspore culture, and presenting a new MS medium-based protocol for androgenic plant regeneration in eggplant (Solanum melongena L.)

The androgenesis is efficiently used to produce doubled-haploid plants. Currently, the modified NLN medium is the only suggested medium for microspore culture in eggplant. In this study, we have investigated the effects of three different types of media (modified NLN, Gamborg's B5, and Murashige and Skoog (MS)) on the induction of microspore androgenesis in eggplant. B5 medium with 2% sucrose, 0.5 mg/L 6-Benzylaminopurine (BAP), and 0.5 mg/L 1-Naphthaleneacetic acid (NAA) showed the best results for microspore-derived callus formation. The results exhibit the significant role of the B5 medium in improving microspore androgenesis in eggplant and suggest that this medium can be a new way to progress microspore culture in this plant. We also analyzed the potential of several hormone treatments in MS medium for plant regeneration from microspore-derived calli. The five treatments, M28 (4 mg/L BAP), M19 (8 mg/L BAP + 8 mg/L kinetin = Kin), M25 (4 mg/L Kin + 0.2 mg/L NAA), M20 (0.4 mg/L BAP + 0.4 mg/L Kin), and M27 (4 mg/L BAP + 0.2 mg/L Indole-3-butyric acid = IBA) produced the highest number of shoot primordia in the primary culture, respectively. After subculturing, the M28 treatment had the highest number of shoot primordia and shoots with 1–10 mm and 11–30 mm sizes. The 100 microspore-derived plants were randomly selected and analyzed to determine their ploidy level. The percentages of haploid, diploid, and mixoploid plants were 6%, 84%, and 10%, respectively.