DANDAN WANG& XINHUI LI& ZHIYING CHENG& CHUNLIN Long

In vitro preservation and micropropagation of Oreocharis mileense(W.T. Wang) M. Möller & A. Weber (Gesneriaceae) through shootorganogenesis

In Vitro Cellular & Developmental Biology – Plant

ABSTRACT

Oreocharis mileense (W.T. Wang) M. Möller & A. Weber is endemic to China and was considered to be extinct because it had not been seen in the wild since the first collection in 1906. In 2006, the species was rediscovered in Shilin County, Yunnan Province. Oreocharis mileense was considered critically endangered for its narrow geographic range and extremely small population. An efficient method to preserve plant germplasm by in vitro culturing of O. mileense has not been reported. In this study, an orthogonal array with three factors (6-benzyladenine, BA; α-naphthaleneacetic acid, NAA; and sucrose), at four levels was performed, and shoot induction as well as shoot proliferation were recorded. The results were analyzed to determine the most significant components and the optimum combination for micropropagation of O. mileense. The results showed that: (1) organogenesis was easily induced by different combinations of plant-growth regulators and sucrose; (2) NAA and sucrose had the most significant effect on shoot induction and shoot multiplication, and (3) the optimum induction and proliferation media were .5 mg L^-1 BA + 0.2 mg L^-1 NAA + 30 g L^-1 sucrose and 1 mg L^-1 BA + 0.1 mg L^-1 NAA + 30 g L^-1 sucrose, respectively.

 Original article link: https://link.springer.com/article/10.1007/s11627-018-9941-y

Figure 1. Regeneration of Oreocharis mileensis (W.T. Wang) M. Möller& A. Weber on Murashige and Skoog (MS) medium (Murashige andSkoog 1962). (a) Seed germination on MS medium containing 0.5%activated charcoal after culture for 10 wk. (b) Sterile plantlets derivedfrom aseptic seed germination on MS medium after culture for 9 wk.(c) Adventitious shoots derived from leaf explant on MS medium containing 2 mg L^-1 6-benzylaminopurine (BA) and 0.1 mg L^-1 α-naphthaleneacetic acid (NAA) after culture for 1 mo. (d) Plantlets developed from adventitious shoots grown on MS medium containing 2.0 mg L^-1 BA and 0.1 mg L^-1 NAA after culture for 14 wk. (e) Welldeveloped plantlets were detached and ready for transplanting. (f)Plantlets were transplanted to a pot containing a 2:1 (v/v) soil mixture of humus:red soil. Bars represent 1 cm.

Figure 2 The drawing of Oreocharis mileensis (W.T. Wang) M. Möller& A. Weber (Cited form Wang 1997)

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Figure 3-5 Oreocharis mileensis (W.T. Wang) M. Möller& A. Weber (Photo: Lei Cai, from Yunnan)

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Figure 6-9 Oreocharis mileensis (W.T. Wang) M. Möller& A. Weber (Photo: Bo Pan & Fang Wen, from Guangxi)