In vitro propagation of four threatened Paphiopedilum species (Orchidaceae)

Abstract

The effects of seed maturity, media type, carbon source, and organic nutrient additives on seed germination, protocorm development, and plant growth of Paphiopedilum villosum var. densissimum Z. J. Liu et S. C. Chen were investigated. Micropropagation frequency was enhanced through the use of 200-day-old seed, Knudson C (KC) medium, and the presence of both glucose and coconut milk in the medium. The effects of various plant growth regulators on the frequency of shoot organogenesis in four Paphiopedilum species were also investigated. Explants of P. villosum var. densissimum and P. insigne (Lindl.) Stein incubated in the presence of 5 mg l -1 6-benzyladenine (BA) with 0.5 mg l -1 a-naphthalene acetic acid (NAA) and 0.2 mg l -1 BA with 0.1 mg l -1 NAA, respectively, showed a twofold increase in the frequency of shoot organogenesis. For explants of P. bellatulum (Rchb. f.) Stein and P. armeniacum S. C. Chen et F. Y. Liu, the combination of 5.5 mg l -1 BA with 0.5 mg l -1 NAA and 4 mg l -1 BA with 0.1 mg l -1 NAA, respectively, resulted in the highest frequencies of shoot organogenesis.

Asymbiotic seed germination and multiplication of an endangered orchid – Paphiopedilum venustum (Wall. ex Sims.)

“…On the other hand, bh-supplemented medium generated a maximum of two adventitious shoots per culture and promoted development of healthy plantlets which could be attributed to medium's higher sucrose concentration as has been suggested earlier in Dendrobium species [49]. The promoting effect of bh in supporting proliferations of secondary protocorm-like bodies (PLBs) in Paphiopedilum rothschildianum [16], healthy growth of plantlets in Dendrobium chrysotoxum and Cymbidium pendulum [51] have been reported.…”

“…Presently, efforts have been made to devise a protocol to raise seedlings by achieving optimum seed germination, multiplying the cultures and subsequently acclimatizing the plantlets under in vivo environment. In vitro culture techniques provide a practical system for clonal, rapid mass multiplication of rare, endangered, horticulturally, and therapeutically important genotypes [8][9][10][11][12][13]. Asymbiotic seed germination is an important technique for rescuing and propagating a large number of orchid species and hybrids.…”

“…Asymbiotic seed germination is an important technique for rescuing and propagating a large number of orchid species and hybrids. Few reports of asymbiotic seed germination of Paphiopedilum species are available [10,[14][15][16][17].…”

“…This reduces the frequency of occurrence of undesired somaclonal variations [45]. Growth supplements are able to influence in vitro regeneration, multiplication of protocorm-like body(ies) and growth of the orchid seedlings, their efficacy has been tested in a few Paphiopedilum species and hybrids such as Paphiopedilum phillippinese × Paphiopedilum 'Susan Booth' [46], Paphiopedilum rothschildianum [8].…”

Criopreservação De Sementes Prégerminadas De Orquídeas Tropicais

“…Apesar de algumas orquídeas, ameaçadas de extinção, poderem ser propagadas em meio apropriado in vitro a partir de sementes (LONG et al 2010;DUTRA et al 2009;ÁVILA-DIAZ et al 2009, HOSOMI et al 2012, esta não é uma estratégia fácil de seguir para todos os taxa. Além disso, as sementes de algumas espécies não podem ser armazenadas a baixa temperatura e umidade, pois expressam características intermediárias ou recalcitrantes, uma vez que não toleram dessecação, ou armazenamento em condições de câmara fria (MACHADO NETO; (-196ºC).…”