Direct and indirect in vitro plant regeneration protocol for Dendrobium jerdonianum has been established. Juvenile stem nodal segments were used as explants to initiate the axillary buds/callus. Node explants derived from 7-8 months old in vitro grown seedlings cultured on half strength Murashige & Skoog (MS) medium (½ MS) and supplemented with various plant growth regulators (PGRs) viz., α-naphthalene acetic acid (NAA), 6-benzyl amino purine (BAP), kinetin (KN) and thidiazuron (TDZ) either individually or in combinations produced axillary buds/callus. The highest average number of shoots per explants were achieved in ½ MS medium supplemented with BAP (3.23 μM) induced the optimum response of 76.3% of direct shoots and forming an average number of 4.9 shoots per explant. Synergistic effects of combinations of various PGRs on direct shoot induction were evaluated. The combinations of NAA (0.5 μM) + BAP (1.62 μM) and NAA (0.5 μM) + KN (0.47 μM) induced 70.2 and 64.3% of direct shoots, respectively. On sub-culturing the shoots in the medium containing NAA (2.69 μM) allows for further growth and rooting, developed into plantlets after 14 weeks of culture. The stem nodal explants cultured on ½ MS medium supplemented with NAA (0.5 μM), TDZ (4.54 μM) and combination of NAA (0.5 μM) + TDZ (2.27 μM) induced the optimum amount of organogenic callus of 39.6, 49.3 and 72.6%, respectively. On sub-culturing the organogenic callus derived from the explants developed the protocorm like bodies (PLBs) in the same media. These PLBs differentiated into plantlets after 18-21 weeks of culture. Almost 90% of the plantlets were successfully acclimatized in the potting mixture and established ex vitro.

中文翻译：

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来自稀有兰花石斛石斛的无菌茎节外植体培养的直接和间接器官发生的体外再生。

已经建立了石斛石斛的直接和间接体外植物再生方案。幼年茎节段用作外植体以启动腋芽/愈伤组织。节点外植体来源于在半强度 Murashige & Skoog (MS) 培养基 (½ MS) 上培养并补充各种植物生长调节剂 (PGR) 即α-萘乙酸 (NAA) 的 7-8 个月大的体外生长幼苗， 6-苄基氨基嘌呤 (BAP)、激动素 (KN) 和噻二脲 (TDZ) 单独或组合产生腋芽/愈伤组织。在添加 BAP (3.23 μM) 的 ½ MS 培养基中，每个外植体的平均枝条数最高，可诱导 76.3% 的直接枝条的最佳响应，并且每个外植体平均形成 4.9 个枝条。评估了各种 PGR 组合对直接芽诱导的协同作用。NAA (0.5 μM) + BAP (1.62 μM) 和 NAA (0.5 μM) + KN (0.47 μM) 的组合分别诱导了 70.2% 和 64.3% 的直接芽。在含有 NAA (2.69 μM) 的培养基中继代培养枝条时，可以进一步生长和生根，培养 14 周后发育成小植株。在补充有 NAA (0.5 μM)、TDZ (4.54 μM) 和 NAA (0.5 μM) + TDZ (2.27 μM) 组合的 ½ MS 培养基上培养的茎节外植体诱导的器官发生愈伤组织的最佳量为 39.6、49.3 和 72.6% ， 分别。在对来自外植体的器官性愈伤组织进行传代培养时，在相同培养基中形成了原球茎样体 (PLB)。这些PLB 在培养18-21 周后分化成小植株。