473 KHON KAEN AGR. J. 42 SUPPL. 1 : (2014). KHON KAEN AGR. J. 42 SUPPL. 1 : (2014). แก่นเกษตร 42 ฉบับพิเศษ 1 : (2557). Seed coating with DNA for anti-counterfeiting of cucumber seeds Potjana Sikhao 1 , Piyasak Chaumpluk 2 and Boonmee Siri 1* ABSTRACT: The objective of this experiment was to create seed identity by DNA coating to protect counterfeiting or imitate of inbred line. The experiment was conducted at Transgenic Plant Technology and Biosensor Laboratory, Department of Botany, Faculty of Science, Chulalongkorn University. Cucumber seed were coated with isolation of shrimp virus plasmid DNA as gelatin polymer. Identification of seed was performed by immersing coated seed in 10 µL deionized water for 10 min with gentle agitation and 2 µL of DNA identification. Detection of DNA identifier was carried out based on basic PCR principle. The result was shown that banding pattern of coated seed sample appear and same to banding pattern of plasmid DNA. This method could be created the cucumber seed identity. The cucumber seed quality was assessed by seed germination and speed of germination. The result was shown that seed coating with DNA did not affect on seed quality. Keywords: cucumber seed, seed identity, DNA coating, seed counterfeiting 1 Department of Plant Science and Agricultural Resource, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand. 2 Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Introduction The quality of seed is very important factor of agriculture product. In the last 10 years, both government and private companies have devel- oped many kinds of plants and new plant varie- ties. Nevertheless, there are problems such as counterfeit of the seeds, that have been found and still could be found in the seed market of developing contries (Guan et al., 2013), which was cause crop yield and seed quality to be in low, include has effect on farmer’s interest (Guan et al., 2011). At present, there are many research- es about anti-counterfeiting technologies such as, using Audio MarQ for seed’s ownership (Kasetsart University, 2008), coated tomato and cucumber seed with DNA for identity seed (Chaumpluk, 2009; Srikaow et al., 2010), soaked tobacco seed by using safranine T to fluorescent labeling for an-counterfeiting (Guan et al., 2011) which was similarly to Guan et al. (2013) used rhodamine B, coated pea seed with rhodamine B and safranine T for falsification-preventing (Tian et al., 2013). In addition, Guan et al. (2013) pelleted tobacco seed with fluorescent compound and magnetic powder simultaneously in the same pellet that can be improved anti-counterfeiting technology and en- hanced the seed security. Nevertheless, most of anti-counterfeiting technologies were not easy to preparing and detection process. Nowadays, seed coating method has been used worldwide because chemical coating reagent attaches uni- formly on the seed surface to provide unique characteristics and quality assurance. The main formula of seed coating consists of polymer, sol- vent and additive, the additive used in this re- search is DNA that is used for anti-counterfeit seed. Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the