Immature Embryo Culture Accelerates Soybean Reproductive Phase: A Potential Biotechnology Approach for Shortening Breeding Cycle
By: Teguh Wijayanto, Gusti Ray Sadimantara, Suaib, Norma Arif, Dirvamena Boer, Dedi Erawan, Nuryeni, Nurdin, Mubayyinul Haq
Key Words: BAP, IBA, Immature embryo, Shortened reproduction cycle.
Int. J. Biosci. 9(2), 37-48, August 2016.
The production of soybean seeds for breeding purposes is usually constrained by a long reproductive phase. One possible way to shorten soybean reproduction cycle is through immature embryo culture. This research studied the effect of pod age and phytohormone composition on the growth of soybean plantlets originated from immature embryos, and to compare potential life cycles of soybean plants generated from embryo culture and from conventional method. Two separate experiments were studied, i.e. pod age experiment (2, 3 and 4 weeks after flowering (WAF) embryos) and experiment of phytohormones indolebutyric acid (IBA) and 6-benzylaminopurine (BAP) combinations. Data were analyzed using the SAS 9.1.3 version statistical software, and treatment means were compared using Duncan’s Multiple Range Test. Data indicated that IBA gave better effects on plantlet growth, as compared to no-hormone treatment, but BAP did not provide good effect. The highest stem (28.7 mm), maximum number of root (10.1), and longest root (63.9 mm) per plantlet were obtained from embryos grown on medium supplemented with 1.5 ppm IBA (B1). Four WAF embryos were suitable explants for better soybean plantlet growth, but in most cases, they were not significantly different from 3 WAF embryos. Culture of 3 WAF embryos can potentially shorten soybean’s life cycle (for breeding purposes) by 32 days if compared to conventional propagation using mature seeds. This way could potentially help breeders to plant soybean more often in each year.