Micropropagation of Selected Genotype ofAloe veraL.—An Ancient Plant for Modern Industry

Abstract

Aloe vera Linn. (Syn. Aloe barbadensis Mill; Gwar-patha in Hindi) belongs to family Liliaceae. The plant, for its medicinal properties, has commercial value. Some of the genotypes of Aloe vera are consumed as a vegetable and processed to make curry and other edible products. We report here on the development of an efficient method for rapid clonal propagation by shoot proliferation from axillary meristem (s) of selected germplasm of Aloe vera. Explants were pretreated with 0.1% aqueous solution of both streptomycin and bavistin separately, each for 15 min. These were surface sterilized with 0.1% aqueous solution of mercuric chloride (HgCl 2 ) for 4-5 min and washed several times with autoclaved water. These were kept in a chilled, sterile antioxidant (200.0 mg L -1 of ascorbic acid, 50.0 mg L -1 of citric acid, and 25.0 mg L -1 of polyvinylpyrrolidone; PVP) solution and cultured on semi-solid Murashige and Skoog's (MS) medium. The bud explants produced multiple (10.3 ± 0.675/explant) shoots on MS medium containing 13.32 mM of 6-Benzylaminopurine (BAP) and 100.0 mg L -1 of ascorbic acid, 50.0 mg L -1 each of citric acid and PVP, with The authors are grateful to the Botanical Survey of India (BSI), Jodhpur for providing the valuable plant material during the present investigation. 936 M. Singh et al. 25.0 mg L -1 each of arginine and adenine sulphate as additives. The shoots were further multiplied by (a) repeated transfer to fresh MS medium with additives + 13.32 mM BAP, and (b) subculturing on MS medium with a lower (4.44 mM) concentration of BAP. On MS medium containing 4.44 mM of BAP and additives, a maximum number (27.8 ± 0.63) of shoots were produced. In liquid MS medium with 4.44 mM of BAP, the rate of shoot multiplication increased and the vigor of the shoots improved. One hundred percent of the cloned shoots rooted under in vitro conditions on hormone-free half-strength MS salts containing 200.0 mg L -1 of activated charcoal at 32 ± 2°C. The cloned shoots treated with 2.46 mM of indole-3-butyric acid (IBA) or 2.473 mM of b-naphthoxyacetic acid (NOA) for 5 min rooted under ex vitro conditions in the greenhouse. The rooted plants were hardened in the greenhouse and stored under an agro-net house. The cloned plants were transferred under different field conditions at various sites in Western Rajasthan. These plants grew normally. The higher rate of shoot multiplication and easier approach of direct rooting and hardening make this method superior to the methods previously reported on cloning/tissue culture of Aloe species. From a single shoot bud, approximately 5000 plants can be produced within 180 days.

Plantlet Regeneration from Callus Cultures of Selected Genotype of Aloe vera L.—An Ancient Plant for Modern Herbal Industries

“…Reducing the level of 2,4-D in culture medium and raising osmotic concentration of the medium could reduce the hyper-hydration of cultures. It is also suggested that once meristematic activity is achieved then cultures could be maintained or grown on medium containing lower concentration of plant growth regulators [12]. Therefore cultures were transferred on MS medium containing lower concentration (1.5 mg l −1 ) of 2,4-D along with 0.25 mg l −1 of Kin, 4% carbohydrate source (3.0% sucrose and 0.5% each of maltose and glucose), and additives for multiplication and long-term maintenance of regenerative callus cultures.…”

“…Bairu et al [11] incorporated meta-topolin [6-(3-hydroxybenzylamino) purine] and its derivatives as alternatives to the benzyladenine and zeatin for optimizing the micropropagation protocol for A. polyphylla. Singh et al [12] defined micropropagation system for mass propagation of selected genotypes of A. vera using axillary meristems. Reports on plant regeneration via callus or somatic embryogenesis of A. vera are limited.…”

Shoot regeneration from leaf explants of Withania coagulans (Stocks) Dunal and genetic stability evaluation of regenerates with RAPD and ISSR markers

“…Therefore, it is suggested that once tissue become rejuvenated and regeneration potential is achieved with cytokinins treatments, the tissue become conditioned and thus require a low level of cytokinins for further proliferation. Hyper-hydration could be checked by reducing the level of cytokinins and raising the osmotic concentrations of culture medium (Singh et al, 2009). In the present study significantly elongated and viable micro-shoots were obtained on MS medium with low level (1.11 μM) of BAP.…”

Assessment of Genetic Stability and Instability of Tissue Culture-Propagated Plantlets of Aloe vera L. by RAPD and ISSR Markers

“…Vyas University, Jodhpur served as source of explants. Efficient plantlet regeneration both through direct shoot bud proliferation without callus phase (protocol 1) using axillary shoot buds [10] and indirect shoot bud proliferation via intermediate callus phase (protocol 2) using soft base of inflorescence axis as an explant [11] was achieved. Figure 1 shows a schematic representation of different steps of protocols and Murashige and Skoog's basal medium [22] with plant growth regulators used for plantlet regeneration.…”

“…Efficient plantlet regeneration for a selected genotype of A. vera L. sweet aloe was achieved through direct shoot bud proliferation using axillary shoot buds [10] and indirect shoot bud regeneration via an intervening callus phase using inflorescence axis as explants [11]. Plant tissue culture techniques are of extensive uses where quality material of a selected genotype is required at mass scale, for commercial cultivation and the natural propagation do not meet the required demands.…”