Effect of varying auxin concentrations on corm weight allocation, reproductive characteristics, and stigma yield of saffron (Crocus sativus L.) under aeroponic culture

Moradi, Rooholla; Feizi, Hassan; Saeidnejad, Amir Hossein; Ghalehgolabbehbahani, Arash

doi:10.22048/jsat.2026.557109.1574

Effect of varying auxin concentrations on corm weight allocation, reproductive characteristics, and stigma yield of saffron (Crocus sativus L.) under aeroponic culture

Document Type : Research Paper

Authors

Rooholla Moradi ¹^{, 2}

Hassan Feizi ³^{, 2}

Amir Hossein Saeidnejad ⁴

Arash Ghalehgolabbehbahani ⁵^{, 6}

¹ Department of Plant Production, University of Torbat Heydarieh, Torbat Heydarieh, Iran

² Saffron Institute, University of Torbat Heydarieh, Torbat Heydarieh, Iran

³ -Department of Plant Production, University of Torbat Heydarieh, Torbat Heydarieh, Iran

⁴ Crop and Horticultural Science Research Department, Kerman Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Kerman, Iran

⁵ Adjunct Assistant Professor at University of Vermont, USA

⁶ Research Director at Rodale Institute

https://doi.org/10.22048/jsat.2026.557109.1574

Abstract

This study was conducted to evaluate the effects of priming saffron corms with different auxin concentrations (0, 1, 2.5, 5, 10, 25, 50, 100, 250, 500, and 1000 mg.kg^-1) on vegetative, reproductive, and propagation traits under aeroponic conditions. A completely randomized design with three replications was used during 2021–2022 at the research laboratory of the Faculty of Agriculture, Shahid Bahonar University of Kerman, Iran. The results revealed that saffron responses to NAA pre-treatment were predominantly dose-dependent and exhibited a biphasic pattern. At the propagative level, the greatest stimulation of lateral bud emergence occurred at lower concentrations. Specifically, 5 and 10 mg.kg^-1 significantly increased the mean number of lateral buds by approximately 75% and 66%, respectively, compared with the control. Conversely, intermediate concentrations, particularly 50 and 100 mg.kg^-1, partially inhibited bud formation. The lowest value (1.4 buds) was observed at 250 mg.kg^-1. Reproductive traits followed a quadratic, dose-responsive trend. The maximum values for flower number, flower yield, and stigma dry weight were observed at 250 mg.kg^-1. Leaf length (14.4 cm) and leaf dry weight (2.68 g per plant) also peaked at this concentration. With respect to corm multiplication, the highest number of reproductive corms per 100 mother corms was recorded at 10 mg.kg^-1(525 corms). The lowest value (258 corms) was observed at 250 mg.kg^-1. However, the mean reproductive corm weight was maximized at 250 mg.kg^-1(11.06 g). The distribution of corm weight was strongly influenced by auxin concentration. Lower doses (5–10 mg.kg^-1) produced a higher proportion of small corms (<5 g; ≈73% at 5 mg.kg^-1and ≈63% at 10 mg.kg^-1), whereas 250 mg.kg^-1increased the proportion of large corms (>10 g) to about 45%. Overall, the findings indicate that lower auxin concentrations (5–10 mg.kg^-1) are more suitable for mass propagation. Intermediate concentrations particularly 250 mg.kg^-1 are recommended to enhance flower yield and produce larger corms, which are desirable for economic and production purposes.

Keywords

Auxin, Corm

Lateral bud

Stigma

Naphthalene acetic acid (NAA)

Subjects

Biotechnology and genetics

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