Rapid in vitro propagation of Limonium wrightii (Hance) Ktze. (Plumbaginaceae), an endangered medicinal plant, was achieved by culturing the shoot-tip (primary and lateral), leaf-and inflorescence-node explants. MS (Murashige and Skoog, 1962) medium supplemented with 8.87 mM N 6 -benzyladenine (BA) and 1.07 mM a-naphthaleneacetic acid (NAA) supported induction of adventitious shoots from the shoot-tip, inflorescence-node and middle and basal parts of leaf explants after 60 d of culture. Adventitious shoots were multiplied by subculturing on MS medium supplemented with BA (2.21-17.75 mM) in combination with NAA (1.07 mM). The percentage of explants forming shoots and the average number of adventitious shoot buds produced per explant were stimulated by increasing the strength (1/4Â, 1/2Â, 1Â, 2Â) of the MS medium. Shoots were rooted on MS basal medium with 4.92 mM indole-3-butyric acid. Plantlets with a morphologically normal appearance produced from adventitious shoots were transferred to soil and acclimated in the growth chamber for 1 mo.

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To screen out cultivars with excellent tissue culture capacities for genetic transformation, the callus induction and regeneration response of immature embryos, inflorescences and anthers from 50 China new released cultivars with excellent agronomic performance were evaluated. The results showed that, among the surveyed cultivars, the callus induction frequency of immature embryos and inflorescences were genotype-independent. Whereas, the regeneration frequency of callus induced from immature embryos were significantly different, with less than 60%, from 60 to 80% and more than 90% in 36, eight and six cultivars, respectively. The regeneration frequency of the induced callus from inflorescences differed significantly, with less than 60%, from 40 to 90% and more than 90% in 34, 11 and five cultivars, respectively. However, both the callus induction and green plantlets regeneration frequencies of anthers were significant different among the cultivars, with the induction frequency less than 25%, from 25 to 60%, and more than 75% in 33, 14 and three cultivars, respectively. The green plantlets regeneration frequency of the callus induced from anthers ranged from 42.5 to 88.5% in different cultivars. Tissue culture capacities of immature embryos and inflorescences were highly correlated. Whereas, both of them have low correlations with anther culture capacity.