Short-term storage of alginate-encapsulated protocorm-like bodies of Dendrobium nobile Lindl.: an endangered medicinal orchid from North-east India

Abstract

Synthetic seed technology is an exciting and rapidly growing area of research as deals with conservation and storage of rare, endangered and desirable genotypes along with its easy handling and transportation. As propagation of many ornamental and medicinally important plant species is labour intensive, application of different growth retardants and osmotica in simple artificial seed system would dramatically reduce labour requirement by storing the germplasm in vitro. Moreover, the primary aim of developing in vitro storage methods is to reduce the frequent demands of subculturing and preserving the unique genetic constituent of the germplasm. Dendrobium nobile is a pharmaceutically important orchid mostly used in the Chinese herbal drug industry for its medicinal property. Commercial exploitation of this species has considerably depleted their population in wild. Hence, for conserving this valuable germplasm, short term in vitro storage of Protocorm-Like Bodies (PLBs) of D. nobile was carried out using different osmotica (sucrose and mannitol). It was observed that incorporation of low sucrose and mannitol (3 and 5 %) in the encapsulating matrix showed almost similar results with that of control. In all these cases, more than half of PLBs burst out from the matrix thus making these concentrations of sucrose and mannitol along with control not suitable for storage studies. However, with the increase in concentration to 7.5 and 12.5 % in the encapsulating matrix, no outburst of encapsulated PLBs was recorded till 60 days of storage; hence it can be concluded that these concentrations play an important role in minimizing the growth of PLBs during storage condition.

Establishment of Efficient in vitro Culture and Plantlet Generation of Tomato (Lycopersicon esculentum Mill.) and Development of Synthetic Seeds

“…However, Saiprasad and Polisetty (2003) observed complexation of 3% sodium alginate with 75 mM CaCl 2 for 20-30 min as optimum combination for proper hardening of beads in different orchids. Also Mohanty et al (2013) found 3% sodium alginate solution with 10 mM CaCl 2 as favourable proper synthetic seed formation in Dendrobium orchids. The increased in sodium alginate concentration at 3% along with gradual raised in CaCl 2 at 25, 50, 75 and 100 mM produced soft, firm and very less transparent beads which were not suitable for encapsulating plant propagules.…”

Artificial Seed for Short-Term Storage:Using Nodal Buds in <i>Aquilaria malaccensis</i> Lam

“…However, no regeneration was recorded from encapsulated nodal buds stored for 60 days at 23 ± 2°C (Table 2). There are reports on rupture of encapsulation matrix during storage that hindered further storage 25,27 . However, in the present study rupture of encapsulation matrix was not observed; instead the nodal buds turned yellowish or brownish with increase in storage duration resulting a decline in regeneration (Figure 6).…”

Mining of miRNAs from EST data in Dendrobium nobile

“…Moreover genetic diversity studies indicate that D. nobile from Northeast India has a comparatively higher rate of genetic diversity [6,7]. The orchid, being prized for its immense commercial importance, is often subjected to unrestrained anthropogenic pressures, thereby threatening its natural population [8]. In addition to its health benefits and economic value, D. nobile is also a wonderful source of experimental material to expound gene expression and regulation because of its versatile characteristics; the availability of decent numbers of expressed sequence tags of this species also augmented this study.…”