EMBRYO CULTURE Effects of cefotaxime, amino acids and carbon source on somatic embryogenesis and plant regeneration in four Indian genotypes of foxtail millet (Setaria italica L.) Lakkakula Satish 1 & Periyasamy Rathinapriya 1 & Stanislaus Antony Ceasar 2 & Arokiam Sagina Rency 1 & Subramani Pandian 1 & Ramakrishnan Rameshkumar 1 & Alagesan Subramanian 3 & Manikandan Ramesh 1 Received: 21 March 2015 /Accepted: 7 September 2015 / Editor: Ewen Mullins # The Society for In Vitro Biology 2015 Abstract The effects of cefotaxime, amino acids and carbon source on somatic embryogenesis and plant regeneration using mature seeds in four genotypes ( ‘ CO5’ , ‘ CO7’ , ‘TNAU43’ and ‘RS118’) of foxtail millet have been studied. The ‘CO5’ gave a superior response in callus induction, so- matic embryogenesis and regeneration. The highest percent- age (69.3%) of embryogenic callus induction was obtained in ‘CO5’ on Murashige and Skoog (MS) medium supplemented with 3.5 mg L -1 2,4-dichlorophenoxyacetic acid (2,4-D), 1 mg L -1 kinetin and 1 mg L -1 1-naphthaleneacetic acid (NAA). Somatic embryogenesis and shoot regeneration were influenced by amino acids, carbohydrates and cefotaxime in culture medium. Maximum response of somatic embryo in- duction and maturation was seen on MS medium containing 3.5 mg L -1 2,4-D, 1 mg L -1 kinetin and 1 mg L -1 NAA, 750 mg L -1 proline, 2.0 mg L -1 glycine, 150 mg L -1 arginine, 800 mg L -1 casein enzymatic hydrolyzate, 20 g L -1 each sucrose and maltose and 500 mg L -1 cefotaxime. The highest frequency of plant regeneration with 21.3 shoots was obtained in ‘ CO5 ’ on MS medium containing 3 mg L - 1 6- benzylaminopurine, 0.2 mg L -1 2,4-D, 750 mg L -1 proline, 2.0 mg L -1 glycine, 150 mg L -1 arginine and 800 mg L -1 casein enzymatic hydrolyzate. The highest response of root induction with more roots and longer roots was observed in ‘CO5’ when cultured on half-strength MS medium. The in vitro-regenerated plantlets were carefully transferred to soil cups, maintained in growth chamber for a week, hardened and grown to maturity in the field. Keywords Amino acids . Cefotaxime . Foxtail millet . Regeneration . Somatic embryogenesis Introduction Millets are essential, staple and ethno-botanical crops in Asia, Europe, Australia, North Africa and North America (Wang et al. 2011). Millets help supply protein and energy for about 130 million people in Sub-Saharan Africa (Austin 2006). According to statistics from the Food and Agriculture Organization (FAO), about 30 million tons of millet grains are produced per annum (Zhang et al. 2014). Foxtail millet is the second-most widely cultivated millet worldwide, and it is still an important crop in semi-arid regions such as India and China (Sato et al. 2013). It is also closely related to bio-fuel grasses such as switchgrass (Panicum virgatum), napier grass ( Pennisetum purpureum) and pearl millet ( Pennisetum glaucum), for which it represents a genetically amenable mod- el crop (Ceasar et al. 2014). Foxtail millet contains high amounts of protein and minerals and has medicinal properties (Suma and Urooj 2012). Because of its smaller genome Lakkakula Satish and Periyasamy Rathinapriya contributed equally to this work. Electronic supplementary material The online version of this article (doi:10.1007/s11627-015-9724-7) contains supplementary material, which is available to authorized users. * Lakkakula Satish pandu.pine@gmail.com * Manikandan Ramesh mrbiotech.alu@gmail.com 1 Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, Tamil Nadu 630 004, India 2 Division of Plant Biotechnology, Entomology Research Institute, Loyola College, Chennai, Tamil Nadu 600 034, India 3 Department of Millets, Tamil Nadu Agricultural University (TNAU), Coimbatore, Tamil Nadu 628 502, India In Vitro Cell.Dev.Biol.—Plant DOI 10.1007/s11627-015-9724-7