INTERNATIONAL JOURNAL OF BUSINESS, SOCIAL AND SCIENTIFIC RESEARCH ISSN: 2309-7892, Volume: 3, Issue: 4, Page: 247-252, July-September 2015 z EFFECT OF GROWTH REGULATORS ON CALLUS INDUCTION AND SHOOT REGENARATION OF LETTUCE (BARI Lettuce-1) S. M. Ahsan 1* , Md. Roman Akon 1 , Maria Akter Sathi 1 , Meherunnesa Papry 1 , Debasish Mondal 2 and Sheikh Rashel Ahmed 3 S. M. Ahsan, Md. Roman Akon, Maria Akter Sathi, Meherunnesa Papry, Debasish Mondal and Sheikh Rashel Ahmed (2015) Effect of Growth Regulators on Callus Induction and Shoot Regenaration of Lettuce (Bari Lettuce-1). Int. J. Bus. Soc. Sci. Res. 3(4): 247-252. Retrieve from http://www.ijbssr.com/currentissueview/14013113 Received Date: 15/08/2015 Acceptance Date: 12/09/2015 Published Date: 13/09/2015 Abstract An experiment was carried out at the Plant Biotechnology Lab, Department of Horticulture, Patuakhali Science and Technology University, Dumki, Patuakhali during the period from Nov. 2013 to Mar. 2014. The experiment was laid out in a Completely Randomized Design with four replications. The experiment was conducted in vitro for the development of an efficient regeneration protocol in BARI Lettuce-1 from leaf explant. The leaf explants were used in in vitro culture for callus induction, shoot regeneration and root formation. Different concentrations and combinations of growth regulators were added to Murashige and Skoog medium to observe their efficacy on callus induction, shoot initiation and root formation. The combination of 2.5 mg/L BAP+0.1 mg/L NAA (Fresh wt. of callus 1.624g at 45 DAC) and 1.5 mg/L BAP+0.25 mg/L NAA ( Dry wt. 0.159g at 45 DAC) was found the best for callus initiation. Shoots were regenerated from the initiated calli upon transfer to Murashige and Skoog medium supplemented with different concentrations and combinations of PGRs. Murashige and Skoog medium supplemented with 2.5 mg/L BAP+0.1 mg/L NAA was the best for shoot induction. Regenerated shoots were transferred to medium containing various levels of Indole-6-Butyric Acid for rooting. Indole-6-Butyric Acid at 1.25 mg/L produced maximum number of roots (14.57), maximum number of leaves (13.82) and the longest (6.382 cm) of plantlets at 45 days after culture. Key words: in vitro, protocol, lettuce, growth regulators, callus. Introduction Lettuce (Lactuca sativa L.) is an annual crop under the family Asteraceae. One advantage of lettuce is that it provides people with various essential vitamins and minerals. It is rich in potassium and vitamin A, which plays an important role in the balance of body liquid. Lettuce is a highly nutritious vegetable and that is why its production worldwide increases tremendously. World production of lettuce and chicory for calendar year 2010 stood at 23,620,000 metric tons over half of which came from China (53%) (FAO, 2007). But Bangladesh yet not contributes in world production of lettuce. Normally, lettuce is propagated through seed. In Bangladesh, production of lettuce fully depends on imported seed. As a result, it becomes the commodity of elite people of Bangladesh. It is necessary to find alternate way to cultivate lettuce. Lettuce can be cultivated by cutting in green house or tissue culture technique. Among the alternatives cutting in green house is really expensive compare to tissue culture technique. To produce genetically identical type plantlet, tissue culture is one of the best ways. Lettuce is mainly cool season plant, so that in vitro regeneration protocol and proper acclimatization of regenerated plantlets is essential for off– season production of lettuce. Protocol development for plant regeneration of lettuce has already been developed but very little studies have been so far attempted in Bangladesh. Lettuce can be regenerated from different plant parts of its plant, such as auxiliary bud, apical buds (Nishio et al., 1988), cotyledons and hypocotyls (Webb and Torres, 1994). It can also be regenerated from protoplast which is amenable to suspension culture (Matsumoto, 1991). Plant regenerated from protoplasts has proved a very useful technique for crop genetic improvement and somatic hybridization. There have been some reports about protoplast culture of lettuce (Brown et al., 1986). The present study was undertaken to develop a protocol for leaf micropropagation of lettuce for high frequency plantlet regeneration and to assess the effect of different concentrations and combination of growth regulators viz. indole acetic acid (IAA), α-naphthalene acetic acid (NAA), and 6-benzylaminopurine (BAP) on callus initiation, shoot regeneration and subsequent rooting of the shoots. Materials and Methods The experiment was laid out in a Completely Randomized Design (CRD) with four replications. The soft part of plantlets (one month aged) such as leaves segment of winter lettuce variety cv. “BARI Lettuce-1” was used as explants in present experiment. Different concentrations and combination of growth regulators viz. 6- *Corresponding Authors Email: smvahsan@gmail.com 1 Department of Horticulture, Patuakhali Science and Technology University, Patuakhali-8602, Bangladesh. 2 Department of Soil Science, Patuakhali Science and Technology University, Patuakhali-8602, Bangladesh. 3 Department of Genetic Engineering and Biotechnology, University of Chittagong, Chittagong, 4331, Bangladesh