Somatic embryogenesis and organogenesis in Dendrocalamus hamiltonii

Abstract

In this study, mature zygotic embryos, plant growth regulators, and various media were tested with the aim of developing an efficient regeneration system for plantlets of the bamboo species Dendrocalamus hamiltonii. Callus formation was induced in explants cultured in Murashige and Skoog (MS) medium supplemented with 1.0-3.0 mg/l 2,4-dichlorophenoxyacetic acid. Optimal shoot differentiation and subsequent shoot growth were also obtained in MS medium supplemented with 2 mg/l benzyladenine, 1 mg/l kinetin, and 1 mg/l naphthaleneacetic acid. Root induction was enhanced by the addition of 5 mg/l indole-3-butyric acid to the culture medium. Histological analysis revealed that both somatic embryogenesis and organogenesis were induced during callus initiation, shoot differentiation, and the development of plantlets from the mature zygotic embryos. Our data provide a useful basis for developing culture protocols for the regeneration of bamboo plants.

Bamboo Regeneration via Embryogenesis and Organogenesis

“…Bamboo can regenerate via embryogenesis and organogenesis (Fig.2e-k), and the frequency of embryogenesis is lower than that of organogenesis (Ramanayake & Wanniarachchi, 2003;Woods et al, 1992;Zhang et al, 2010).…”

“…Histological analysis reveals that embryogenic cells are small in size, isodiametric with dense cytoplasm, generally locate along the periphery of calli, distribute in clusters, and intersperse with large parenchymal cells. Somatic embryos gradually developed from the granular onsite to heartshaped, torpedo-shaped, and final cotyledons (Zhang et al, 2010).…”

“…Histological analysis shows that non-embryogenic cells are large, and vacuolated parenchymal cells contain few plastids (Zhang et al, 2010). Callus will differentiate into adventitious shoots, and develop with subsequent formation of adventitious roots.…”

“…Gene transformation is another efficient approach to increase productivity and quality in plants. However, there have been no successful reports on bamboo gene transformation till now, because a stable and efficient regeneration system, the prerequisite to bamboo gene transformation, is still not completely established yet (Huang et al, 1989;Zhang et al, 2010;Zuo & Liu, 2004Saxena & Dhawan, 1999;Zhang et al, 2010). After inoculation, calli are induced in the medium with a high concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) usually.…”

“…After rooting, the plantlet can be transferred to potting soil in the greenhouse (Fig.2j). (Huang et al, 1989;Yeh & Chang, 1986a, 1986bZhang et al, 2010). …”