Developing a high-efficiency in vitro propagation system for Cymbidium goeringii: Impact of decomposed squid on rhizome proliferation
摘要
Cymbidium goeringii Rchb. f. is an endangered orchid that is difficult to culture due to low rhizome proliferation, limited differentiation, and severe browning. An in vitro propagation system was established to culture this orchid by evaluating the effects of different basal media and decomposed animal-derived additives on rhizome proliferation, and the effects of anti-browning agents on rhizome differentiation and shoot rooting. Optimal medium for rhizome proliferation was determined to be 1/2 Murashige and Skoog (MS) supplemented with 0.5 mg·L−1 6-benzylaminopurine (6-BA), 1.0 mg·L−1 α-naphthaleneacetic acid (NAA), 7.5 g·L−1 activated charcoal, and 0.1 g·L−1 decomposed squid, resulting in a rhizome proliferation coefficient of 15.0 within 90 d. For rhizome differentiation, 1/2 MS supplemented with 1.0 mg·L−1 6-BA, 0.1 mg·L−1 NAA, and 0.25 g·L−1 succinic acid, significantly suppressed browning (9.5% rate after 30 d), and induced an average of 5.5 shoots per rhizome. The most effective rooting medium was 1/2 MS supplemented with 1.0 mg·L−1 indole-3-butyric acid, 0.5 mg·L−1 NAA, 2.0 g·L−1 activated charcoal, 100.0 mL·L−1 coconut water, and 3.0 g·L−1 polyvinyl pyrrolidone (yielding a 96.0% rooting rate, 2.8 cm average root length, and 2.2 roots per seedling within 40 d). This new protocol provides an efficient method for rapid propagation of C. goeringii to support its conservation and potential commercial cultivation.