The encapsulated shoot tips and nodal segments of Eclipta alba were stored at 4, 12 and 20 °C under irradiance of 1.5 μmol m -2 s -1 and high conversion was observed in synseeds stored at 4 °C for 8 weeks. Duration of storage was extended up to 12 weeks by decreasing sucrose concentration in the alginate matrix from 3 to 1 or 2 % and conversion frequency was 71.2 -76.1 %. Synseed-derived plantlets survived by 100 % in ex vitro conditions. RAPD analysis revealed uniform amplification profile in donor and synseed derived plantlets.Additional key words: alginate matrix, encapsulated explants, ex vitro transfer, genetic uniformity, sucrose.
⎯⎯⎯⎯Eclipta alba is a common herb of tropical, subtropical and temperate climate. In current years, the plant has been harvested in huge quantities from the wild to meet up the pharmaceutical demand. For this use, cultivation of Eclipta alba is preferred to the collection, however, systematic cultivation of this plant is not adopted till date. Moreover, the seeds are very small, wind dispersed (Neff and Baldwin 2005) and fast germinating (within less than 5 d of shedding; Ferreira et al. 2001).Synthetic seed (synseed) has become an efficient tool that facilitates conservation as well as mass propagation of elite plant species by encapsulating somatic embryo or meristem tissue. Inclusion of meristematic tissues instead of somatic embryos hastened widespread exploitation of this technology in recent years. Encapsulation of meristematic tissues of E. alba for developing alternate germplasm source is an attractive option in the above mentioned situation. Although continuous production of E. alba can be achieved through micropropagation (Ray and Bhattacharya 2008) its high growth rate limits storage and maintenance under in vitro condition as frequent subcultures are required. Encapsulation provides two-fold advantages, synseeds offer short term conservation of germplasms; besides, germinating synseeds can provide readily available tissue source for easy mass propagation where each synseeds can virtually act as zygotic seeds giving rise to plantlets. Finally, synseedgenerated plantlets with their genetic fidelity confirmed through RAPD analysis ensured raising of genetically homogenous plant population.The aim of present research was optimization of storage period and conversion frequency of E. alba synseeds by changing physico-chemical condition of storage. Suitable storage temperature was selected in the first step followed by optimization of sucrose concentration in the beads. The study also included experimentation on ex vitro survival of synseed-derived plantlets and checking their genetic fidelity by RAPD analysis.In vitro culture of Eclipta alba (L.) Hassk. was established according to Ray and Bhattacharya (2008). Axenic shoot tips and nodal segments were dissected from in vitro plantlets and were used as explants for encapsulation. Explants mixed with 3 % sodium alginate were suspended drop wise in 1.11 % CaCl 2 solution so that each drop contained single explant. They were kep...