Contents lists available at ScienceDirect Scientia Horticulturae journal homepage: www.elsevier.com/locate/scihorti Regulation of dedifferentiation and differentiation in different explants of Papaver rhoeas L. by one-step culture Zahra Aghaali a,b , Yoichiro Hoshino b, ⁎ , Sajad Rashidi Monfared c , Ahmad Moeini a a Department of Genetic and Plant Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran b Field Science Center for Northern Biosphere, Hokkaido University, Kita 11, Nishi 10, Kita-Ku, Sapporo 060-0811, Japan c Department of Agricultural Biotechnology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran ARTICLE INFO Keywords: Callus induction Corn poppy Shoot formation ABSTRACT The corn poppy (Papaver rhoeas L.) is an important horticultural plant and one of the most well-known members of the Papaveraceae. The species is also used for the treatment of various diseases in folk medicine. Using a biotechnological approach, this species can be further improved. However, the corn poppy is a recalcitrant plant species for tissue culture. Here, we investigated what effects explant type and different auxins and cytokinins had on callus induction and shoot formation. Root, hypocotyl, cotyledon, petiole, and leaf explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of the auxins picloram, naphthaleneacetic acid, and 2,4-dichlorophenoxyacetic acid (0.5 and 1.0 mg L -1 ) and the cytokinins 6-Benzylaminopurine (BAP) and kinetin (0.1 and 0.5 mg L -1 ). There was a significant difference in callus in- duction among the explants and combinations of plant growth regulators at p = 0.001 and p = 0.05, respec- tively. The best results for callus induction were observed in petiole and leaf explants on MS medium containing 1.0 mg L -1 picloram and 0.1 mg L -1 BAP (89.2%). Adventitious shoots frequently formed when root explants were cultured on MS medium with 1.0 mg L -1 picloram and 0.5 mg L -1 BAP. Over 70.8% of the root explants successfully produced adventitious shoots, but the other explants did not exhibit any shoot formation. Therefore, we found the optimal culture media for regulating dedifferentiation (callus induction) and differentiation (shoot formation) by using several explants. 1. Introduction The corn poppy (Papaver rhoeas L.) (2n = 14) is one of the most well-known members of the genus Papaver (Papaveraceae), and is easily identified by its scarlet flowers. It is native to subpolar regions of Europe, Asia, and North America, and the mountains of Central Asia. It is an annual, insect-pollinated species with high self-incompatibility and outcrossing contributes to high levels of genetic variation and heterozygosity (Hamrick and Godt, 1996). As the flowers have high ornamental value, this plant species has been cultivated all over the world. Moreover, corn poppy has been used for researches on self-in- compatibility (Eaves et al., 2014) and pollen tube development (Franklin-Tong et al., 1996). In addition, pharmacological studies in the corn poppy have revealed that the plant’s extract has several beneficial properties, such as being anticarcinogenic (Ghizlane and Aziz, 2016), antimicrobial (Çoban et al., 2017), antispasmodic (Baghdikian et al., 2013), antioxidant (Hillenbrand et al., 2004), antiulcerogenic (El and Karakaya, 2004), antidepressant (Osanloo et al., 2016), and mild se- dative (Çoban et al., 2017). Rhoeadine is an alkaloid derived from the flowers, and is used as a mild sedative and mild antitussive (Matysik and Benesz, 1991). Thus, the corn poppy is not only an important horticultural crops but also experimental plant species and medical plant. To increase horticultural values and to analyze machinery of self- incompatibility and pollen tube development as well as medicinal compounds, genetic transformation of the corn poppy for introducing foreign genes is very useful. However, the corn poppy is still one of the recalcitrant plant species for tissue culture and in vitro plant re- generation system. Therefore, there is no report for genetic transfor- mation in the corn poppy. Tissue culture and plant regeneration systems have been established in other members of the papaver, including P. somniferum L. (Facchini et al., 2008; Royandezagh et al., 2013), P. bracteatum Lindl. (Ilahi and Ghauri, 1994; Rostampour et al., 2009), P. orientale L. (Zakaria et al., 2011) and P. nudicaule L. (Yang et al., 2010). By referring the previous https://doi.org/10.1016/j.scienta.2018.11.009 Received 15 July 2018; Received in revised form 16 October 2018; Accepted 3 November 2018 Abbreviations: BAP, 6-benzylaminopurine; 24-D, 2,4-dichlorophenoxyacetic acid; NAA, naphthaleneacetic acid; PGR(s), plant growth regulator(s) ⁎ Corresponding author. E-mail address: hoshino@fsc.hokudai.ac.jp (Y. Hoshino). Scientia Horticulturae 246 (2019) 366–370 0304-4238/ © 2018 Elsevier B.V. All rights reserved. T