Influence of Gelling Agent on Micropropagation Cost and in Vitro Conservation of Turmeric (Curcuma longa) Germplasm
DOI:
https://doi.org/10.21921/jas.v3i4.6703Abstract
This study was designed to examine the effect of different gelling agents on shoot multiplication and low cost in vitro conservation of Curcuma. Shoot bud explants of C. longa cv. Sona were cultured on modified Murashige and Skoog (MS) media supplemented with 2.5 mg l-1 BAP + 3% sucrose. Six gelling agents viz. 7 g l-1 Agar (Himedia PT Pure), 2.5g l-1 Clarigel (Himedia), 4.5 g l-1 Clarigar (Himedia), 6 g l-1 Gelzen (Sigma), Isabgol 3.5 g l-1 (Baidyanath) and 2.5 g l-1 Phytagel (Sigma) were used to study their effect on micro propagation and cost effective in vitro conservation. Highest rate of shoot multiplication was recorded with 2.88± 0.03 shoots/ explant in the media solidified with clarigar compared to regularly used gelling agent agar (2.31± 0.38). After 12 months of conservation, highest 85% survival of cultures was also recorded in the medium solidified with Clarigar, whereas only 50% of cultures survived on agar supplemented media. Regenerated plantlets were acclimatized successfully and produced healthy rhizomes using soil: sand: Farm Yard manure 2:1:1 with 95% survival.
References
Cheaper alternatives to agar include various types of starches and plant gums (Pierik, 1989, Nagamori and Kobayashi, 2001). The National Research Development Corporation, India (NRDC, 2002) has listed low cost agar alternatives, which are worth evaluating for routine use in commercial micropropagation. Gelrite can be replaced with starch-Gelrite mixture (Kodym and Zapata, 2001). The use of liquid media eliminates the need of agar. Other options include white flour, laundry starch, semolina, potato starch, rice powder and sago. For micropropagation of ginger and turmeric, the combination of certain gelling agents gave growth as good as on agar-based media (Table 1). The use of laundry starch, potato starch and semolina in a ratio of 2:1:1 reduced the cost of gelling agent by 70-82% (Prakash, 1993). However, the addition of such gelling agents to the medium also has some disadvantages. Some gelling agents contain inhibitory substances that hinder morphogenesis (Powell and Uhrig, 1987), and reduce the growth rate of cultures. Moreover, toxic exudates from the cultured explants may take a longer time to diffuse. Media solidified with gelling agents increase the time to clean the culture containers. The low cost options to agar, agarose, and gellan gum are listed below (Table 1 and 2).
