3535 Original Article COST EFFECTIVE PLANT REGENERATION PROTOCOL FOR ROUGH LEMON (CITRUS JAMBHIRI LUSH) USING GUM KONDA- GOGU AS GELLING AGENT IN PLANT TISSUE CULTURE MEDIA SINGH, B., 1 SINGH, J. 1 AND KAUR, A. 2 1 Plant Tissue Culture Laboratory, Department of Biotechnology, Khalsa College Amritsar 143 002 (Punjab), India; 2 Department of Food Science & Technology, Guru Nanak Dev University, Amritsar 143005, India. E. mail: bbs171@rediffmail.com Received: November 11, 2012; Accepted: January 22, 2013 Abstract. The goal of this study was to develop cost effective regeneration protocol for rough lemon using natural exudate gum from Cochlospermum gossypium (gum kondagogu) as gelling agent in plant tissue culture media. Nodal segments of rough lemon (Citrus jambhiri Lush) were cultured on MS medium supplemented with kinetin (KN) 2 mg/l and gelled with agar or gum kondagoggu alone and in combinations. Maximum 66.66% cultures showed shoot regeneration on 0.8% agar gelled medium (control) with an average shoot length of 0.74 cm. The shoot regeneration response on media gelled with 3% gum kondagogu was 63.88 % with an average shoot length of 0.79 cm. Use of agar (0.1 to 0.3%) along with gum kondagogu (2.5 and 3%) improves shoot regeneration response but there is decrease in average shoot length. Regenerated shoots were rooted on MS medium supplemented with Indole-3-butyric acid (IBA) 2 mg/l and gelled with agar or gum kondagogu alone and in combinations. In agar gelled medium (control), 52.77 % cultures showed root regeneration with an average root length of 5.48 cm. In 3% gum kondagogu gelled medium maximum of 52.08 % cultures showed root regeneration with an average length of 5.53 cm. Addition of agar in 3% gum gelled medium decreases root regeneration response and average root length. Firmness of gum gelled medium was less as compared to agar gelled medium. However, there was no significant difference in regeneration response of nodal explants on agar (0.8%) and gum (3%) gelled medium. Cost of gum kondagogu is 6.5 times less than that of agar so it can be used as gelling agent to reduce production cost of tissue culture raised plantlets. Key words: Citrus jambhiri, Gum kondagogu, Tissue culture INTRODUCTION Micropropagation laboratories all over the world are currently multiplying large number of clones of important plants. Plant tissue culture provides reliable method of producing and propagating pathogen free plants. It may be also useful in providing plant material for in vitro conservation and genetic transformation studies [1,2]. However, this method is more expensive than the conventional methods of plant propagation. It requires the presence of highly responsive regeneration protocol, expensive culture medium, sophisticated instruments and skilled workers. The cost of medium per plant depends on the amount dispensed and the rate of plant multiplication per culture container. It is a capital-intensive industry, and in some cases the unit cost per plant becomes unaffordable. For successful establishment of tissue culture laboratories cost effective culture medium is required. Agar is Journal of Cell and Tissue Research Vol. 13(1) 3535-3540 (2013) (Available online at www.tcrjournals.com) ISSN: 0973-0028; E-ISSN: 0974-0910 ?