Direct organogenesis from leaf explants of Stevia rebaudiana and cultivation in bioreactor

Abstract

Shoot buds were induced directly on either side of midrib from adaxial surface of immature leaf explants in Stevia rebaudiana Bertoni five weeks after culturing in Murashige and Skoog's nutrient medium supplemented with 8.88 μM of N 6 -benzylaminopurine and kinetin ranging from 4.65 to 6.98 μM. Immature leaves of 0.6 to 1 cm were found to produce best response (93 %) with a highest number of 4.93 shoot buds per explant. For elongation of regenerated shoot buds, MS medium supplemented with 30 g dm -3 sucrose and indole-3-butyric acid (IBA) ranging from 4.92 to 7.38 μM were found most suitable. The medium was further modified to suit bioreactor cultivation of regenerated shoots wherein the use of two-fold MS salts and 60 g dm -3 sucrose resulted in a high biomass yield of 50.68 g dm -3 (m/v) accounting for about 590 micro-cuttings in three weeks. Best rooting of micro-cuttings occurred in half strength MS medium supplemented with IBA ranging from 4.92 to 7.38 μM, 15 g dm -3 sucrose and gelled with 0.8 % agar. Rooted plants were successfully established in substrate containing sand, Vermicompost and garden soil in equal proportions and grown in greenhouse. This is the first report on direct shoot regeneration from Stevia leaves.

Cattleya walkeriana growth in different micropropagation systems

“…SILVA et al (2007) working with different methods of pineapple propagation, reported a bigger length of the aerial part with the use of temporary immersion bioreactor, being superior to other methods like continuous immersion bioreactor and conventional micropropagation. Similar results have been found in chrysanthemums ; apples (CHAKRABARTY et al, 2007), in the medicinal plants Crescentia cujete (MURCH et al, 2004) and Stevia rebaudiana (SREEDHAR et al, 2008). MURCH et al (2004), working with different Crescentia cujete growth systems, reported that a bigger growth of the root system was observed in temporary immersion system when compared to the micropropagation in solid and liquid media.…”

In vitro Propagation of Stevia rebaudiana (Bertoni): An Overview

“…Initially, the shoot buds appeared as white knob like structures which later turned green leading to the formation of a pair of green leaves (Sreedhar et al, 2008). In an earlier study, kin in combination with NAA or IAA failed to induce shoot formation on leaf explants of stevia whereas BA was found to be more effective (Sivaram and Mukundan, 2003).…”

Comparative effects of plant growth regulators on leaf and stem explants of Labisia pumila var. alata

“…These vein-derived cells are procambial-like and function as pluripotent stem cells with a tendency to form root meristems or vascular tissues in response to added auxin (Rose et al, 2006). A series of experiments with Cyclamen persicum led to the conclusion that an increased density of vascular tissue will increase root regeneration as a result of the level of phytochromes and other metabolites that are present in the leaf midvein (Sreedhar et al, 2008). Furthermore, the ability of leaf explants in producing its endogenous auxins might also contribute to the more effective adventitious root formation from the leaf than that of stem explants which lack this ability (Vesperinas, 1998).…”