Effect of plant growth regulators and explants on organogenesis of soybean (Glycine max L.)

Objective: The soybean plant is one of the most important crops, and it is known as a rich source of vegetable oil and protein in the world. Despite its advantages, soybean production faces different challenges and requires genetic improvement. Soybean transformation provides an attractive advancement for soybean breeding programs, allowing the production of novel and genetically diverse plant materials. Therefore, developing an efficient plant regeneration protocol is necessary for the transformation programs. In this study, a simple, efficient, and repeatable protocol was developed for in vitro organogenesis of the Saman soybean cultivar.Methods: The soybean seeds were cultured on different strengths of MS medium (full and half-strength MS) in combination with different concentrations of BAP/Kin (۰, ۰.۵, ۱, ۱.۵, ۲, ۲.۵, and ۳ mg/L). After germination, cotyledon, hypocotyl, and primary leaf explants were cultured on the shoot induction media with different concentrations of BAP/Kin (۰, ۱, ۱.۵, and ۲ mg/L) in combination with IBA/NAA (۰, ۰.۱, and ۰.۵ mg/L) to evaluate their organogenesis potential. In the next step, for shoot elongation, all regenerated buds were transferred to two media (MS and ½ MS) in combination with BAP (۰, ۰.۱, ۰.۲, and ۰.۴ mg/L) and GA۳ (۰, ۰.۱, ۰.۵, and ۱ mg/L). At the final stage, for root induction, the elongated shoots were cut and cultured in different strengths of the MS medium (full and half-strength MS) in combination with different concentrations of IAA, IBA, and NAA (۰, ۰.۱, ۰.۵, ۱, ۱.۵, and ۲ mg/L). All experiments were conducted as a factorial arrangement based on a completely randomized design.Results: The results showed that the highest percentage of seed germination (۹۷.۱۸%) was obtained in full-strength MS medium supplemented with ۲ mg/L BAP. The maximum number of shoot induction per explant (۷.۱ shoots) was observed in the medium containing ۱.۵ mg/L BAP and ۰.۱ mg/L IAA from the cotyledon explants. The maximum rate of shoot elongation (۸.۵ cm) was achieved in the half-strength MS medium containing ۰.۵ mg/L GA۳ and ۰.۲ mg/L BAP. Also, the maximum number of roots was produced in the half-strength of MS medium supplemented with ۱.۵ mg/L IBA. Finally, the rooted plantlets after acclimatization were transferred into the greenhouse for flowering and pod maturation.Conclusion: The results of this study can be used for gene transfer and genetic engineering research for the Saman cultivar and other soybean cultivars.

کلیدواژه ها:

Explant ، organogenesis ، rooting ، Shoot elongation ، Soybean