Effects of photoperiod, mineral medium strength, inorganic ammonium, sucrose and cytokinin on root, shoot and microtuber development in shoot cultures of Dioscorea alata L. and D. bulbifera L. yams

Abstract

The effects of photoperiod (8, 12 or 16 h), mineral medium strength (dilutions of a tuberization medium, the T medium), sucrose (0, 2, 4, 8% w/v) and kinetin (0, 2.5 #M) on the development of roots, shoots and microtubers in shoot cultures of Dioseorea alata L. and D. bulbifera L. yams were evaluated. All. of the factors were found to have substantial effects on microtuber induction in these two species. The effects of high and low inorganic ammonium containing media on microtuberization of yam shoot cultures indicated that ammonium ions inhibited microtuber induction in D. alata but not in D. bulbifera. Microtubers ofD. alata were only formed on shoot cultures if these were held under 8-h days. D. bulbifera cultures on the other hand produced microtubers under this photoperiod treatment as well as under 16-h photoperiods provided that kinetin was present in media at 2.5/tM. Most microtuberization in D. alata shoot cultures occurred on full-strength T medium supplemented with 2% sucrose, 2.5/~M kinetin held under 8-h photoperiods at 25 °C, whereas most microtuberization in D. bulbifera shoot cultures occurred on full-strength MS medium supplemented with 4% sucrose, 2.5 ~M kinetin held under 8-h photoperiods at 25 °C. Under these two sets of conditions, yam shoot cultures consistently produced microtubers with individual weights in excess of 100 mg which were large enough to be capable of direct planting and subsequent growth in unsterilized soils.

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

“…The shoots of cassava were induced directly from budded nodal cuttings or indirectly from callus in the presence of BAP. This confirms the highest potential of BAP to induce shoots in different species as reported in several works (Anh Hong et al, 2007;Konan et al, 1997;Fotso et al, 2013;Davies, 2004 , all shoots (100 %) gave rise to plantlets with the highest growth parameters The regeneration of plantlets in the presence of BAP/NAA ratio was already reported in the same specie (Ma and Xu, 2002) or in the other species (Mantell and Hugo, 1989;Fotso et al, 2013;Dhar and Joshi, 2005).This result confirms the complementary and synergize action of auxins and cytokinins in the process of growth and development that has been reported by some authors (Dhar and Joshi, 2005;Vines, 2001;Guo and Zhang, 2005).When acclimatized, plantlets regenerated from Manihot esculenta survived more (100 %) in the mixture red soil/black soil (V/V).This result is in contrasts with acclimatization of many species where plantlets survived in vermiculite or in mixture of vermiculite and soil (Yongqin et al, 2003;Yassen et al, 1995).…”

“…Many factors such as the presence or the absence of growth regulators, the concentration and of sugars, the mineral composition of the medium and the photoperiod were known to influence the organogenesis in vitro (Koda and Kikuta, 1991;Mantell and Hugo, 1989;Santos and Salema, 2000;Ovono Ondo et al, 2007). Therefore, the effect of growth regulators (BAP and NAA) and sucrose, together or in combination with the micropropagation of M. esculenta was studied.…”

In vitro propagation of wild yams, Dioscorea oppositifolia (Linn) and Dioscorea pentaphylla (Linn)

“…the clonal propagation through in vitro production of microtubers in D. abyssinica (Martine and Cappadocia, 1991), D. alata (Mantell and Hugo, 1989;Martine and Cappadocia, 1991;John et al, 1993;Jasik and Mantell, 2000), D. batatas (Koda and Kikuta, 1991), D. composita (Alizadeh et al, 1998) and D. floribunda (Sengupta et al, 1984) The tubers of D. oppositifolia are used as an herbal tonic. It stimulates the stomach and spleen and has an effect on the lungs and kidneys.…”

Physiological, Biochemical and Modern Biotechnological Approach to Improvement of Rauwolfia serpentina

“…Satheesh and Bhavanandan [12] have reported the regeneration of shoots from callus of Plumbagorosea using appropriate concentrations of auxins and cytokinins. Mantell and Hugo [13] have also reported a high frequency of shoot, root, and micro tuber production from Dioscoreaalatadepending on the culture medium used, the type of explant from which the calli originated, and the photoperiod.…”