Journal of Agricultural Technology 2014, Vol. 10(5):1183-1199 1183 Effect of radiation and chemical mutagens on seeds germination of black cumin (Nigella sativa L) M.K.M. Maamoun 2 , M.E. El-Mahrouk 1* , Y.H. Dewir 1 and S.A. Omran 2 1 Horticultural Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt, 2 Department of Breeding and Genetics of Vegetables, Aromatic & Medicinal Plants, Agriculture Research Center, Horticultural Research Institute, Giza, Egypt M.K.M. Maamoun, M.E. El-Mahrouk, Y.H. Dewir and S.A. Omran (2014) Effect of radiation and chemical mutagens on seeds germination of black cumin (Nigella sativa L). Journal of Agricultural Technology 10(5):1183-1199. Nigella sativa L., Rananculaceae, is an important medicinal plant. Seed germination responses to gamma and laser radiation, colchicine and 2, 4 Dinitroaniline chemical mutagens at various doses and concentrations were investigated. Low dose of gamma radiation at 5 Kr stimulated seed germination in dry seeds in which FGP at 83.9% was obtained compare to non-radiated dry seeds at 70.8%. Higher doses of gamma radiation (˃ 5 Kr) had negative effects of seed germination in terms of FGP, GRI and CGRI. Gamma radiation exhibited more severe effects on soaked seeds than dry seeds. Seeds irradiated with 10 and 45 min He-Ne laser gave the highest FGP at 90.07% and 91.67%, respectively. However, 10 min He-Ne laser significantly decreased GRI and CGRI when compared with control seeds and/or other laser doses. In addition, He-Ne laser irradiation decreased the number of days to GT 50 when compared to the control seeds. For chemical mutagens, 20 mg/l 2,4Dinitroaniline improved FGP when compared with other treatments. Also, colchicine and 2,4Dinitroaniline concentrations significantly increase CGRI when compared with control. It is interesting to note that GT 50 was decreased with He-Ne laser radiation and increased with gamma radiation while no significant differences were observed with chemical mutagens. Keywords: Black cumin, gamma radiation, He-Ne laser, colchicine, 2,4Dinitroaniline, seed germination. Introduction For thousands of years, medicinal plants have been the most important source of life saving drugs for the majority of world’s population. Nigella sativa L. (Rananculaceae), an annual herbaceous plant, is commonly known as black seed or black cumin. It has been traditionally used for centuries in the Middle East, Northern Africa and Asia as a spice and food preservative, as well as a protective and curative for numerous disorders and asthma (Nadkarni, * Corresponding author: M.E. El-Mahrouk; e-mail: threemelmahrouk@yahoo.com Journal of Agricultural Technology 2014 Vol. 10(5):1183-1199 Available online http://www.ijat-aatsea.com ISSN 1686-9141