Stimulation of in vitro shoot proliferation from nodal explants of cassava by thidiazuron, benzyladenine and gibberellic acid

Abstract

Multiple shoots were produced from nodal explants of cassava (Manihot esculenta Crantz.) by a two-step procedure: a 6-to 8-day exposure to 0.11 -0.22 #M thidiazuron (TDZ) in liquid Murashige and Skoog (MS) medium followed by culture on agar-solidified MS medium supplemented with 2.2 #M 6-benzyladenine (BA) and 1.6 #M gibberellic acid (GA3). TDZ caused the nodal explants to expand and this expansion (growth) continued during culture with BA and GA3. From this expanded explant, clusters of buds and fasciated stems developed continuously and these gave rise to shoots. The shoot proliferation process was open-ended, yielding an average of 31.5 shoots per nodal explant after 10 weeks of culture with genotype CG 1-56. A positive response was also obtained from seven other genotypes evaluated with this protocol.Abbreviations: BA -6-benzyladenine; BM -basal medium; DPU -1,3-diphenylurea; GA3 -gibberellic acid; 2iP -isopentenyladenine; MSM -multiple shoot medium; NAA -1-naphthaleneacetic acid; PGR -plant growth regulator; TDZ -thidiazuron; Z -zeatin

Effect of exogenous phytohormones and sucrose on micropropagation and microtuberisation of Manihot esculenta Crantz var. TMS 96/0023

“…The first study on tissue culture of cassava was done by Kartha et al (1974) Gibberellic acid (GA3) and 0.2 mg.L -1 Naphylacetic acid (NAA). Bhagwat et al (1996) reported regeneration of multiple shoots from nodal explants of cassava using 0.11 to 0.22 μM.L -1 thidiazuron (TDZ), 2.2 μM.L -1 BAP and 1.6 μM.L -1 GA3. A frequent in vitro culture manipulation for cassava involves standard media such as the Murashige and Skoog (1962) (MS medium), but with altered macroand/or micronutrient concentrations.…”

Shoot regeneration of dwarf dogwood (Cornus canadensis L.) and morphological characterization of the regenerated plants

“…The elongation of the adventitious buds GA 3 is widely used to promote elongation of adventitious shoots in plant regeneration, e.g., for in vitro shoot proliferation of cassava (Bhagwat et al 1996) and regeneration of Acacia mangium via organogenesis (Xie and Hong 2001). In this study, the elongation of the adventitious buds was very slow on the medium containing 4.44 lM BAP and 0.54 lM NAA.…”

Regeneração in vitro de louro-pardo (<i>Cordia trichotoma</i> (Vellozo) Arrabida ex Steudel).

“…Resultados semelhantes foram encontrados por NANNETTI & PINTO (1995) na multiplicação de Heliconia. O thidiazuron é uma feniluréia com ação citocinínica de forte efeito fisiológico na micropropagação de espécies lenhosas podendo substituir o BAP, como demonstram BHAGWAT et al (1996) em brotações múltiplas de Manihot sculent, e em Feijoa sellowiana por DAL VESCO & GUERRA (1999). Segundo ALVES et al (1995), o TDZ é mais ativo na multiplicação que outras citocininas, por causa do aumento da atividade da enzima fosfatase ácida que promove a interconversão nucleotídeo-nucleosídeo da estrutura de citocininas endógenas, tornando-as biologicamente mais ativas, e dessa forma, podendo tornar-se inibidor do crescimento, quando utilizado na mesma concentração de outras citocininas.…”