Efficient Tissue Culture Method Based on Clustered Bud Proliferation for Producing High-Quality Arundo donax Seedlings

For its rapid growth, high yield, and broad adaptability, <i>Arundo donax</i> is widely used in various applications, yielding considerable economic and ecological benefits. However, widespread cultivation is challenging because <i>A. donax</i> can only be propagated asexually. In this study, a tissue culture method was developed using the clustered bud proliferation pathway. The explant type, disinfection method, induction medium, proliferation medium, and rooting medium were optimized to efficiently harvest high-quality <i>A. donax</i> seedlings. Using axillary buds with whole cane fragments as the most suitable explants, they were first sterilized with 75% alcohol for 30 s and then disinfected with 0.1% mercuric chloride for 5 min. 97.8% of explants could successfully form clustered buds on Murashige and Skoog (MS) medium supplemented with 5.0 mg/L 6-benzylaminopurine (6-BA) and 1.0 mg/L 3-indolebutyric acid (IBA). Each individual bud achieved efficient propagation with a proliferation coefficient as high as 33.3 on MS medium supplemented with 4.0 mg/L 6-BA and 1.0 mg/L IBA. In addition, all buds were capable of rooting on 1/2 MS medium supplemented with 0.5 mg/L 1-naphthaleneacetic acid (NAA). The resultant rooted seedlings survived and developed into plantlets, averaging 44.84 cm in height and 2.54 mm in thickness, following a 30-day acclimation period. This protocol provides a robust foundation for the large-scale, high-quality propagation of <i>A. donax</i>, supporting its broader application in ecological restoration and bioresource industries.