VOL. 13, NO. 5, MAY 2018 ISSN 1990-6145 ARPN Journal of Agricultural and Biological Science © 2006-2018 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com 50 THE EFFECTS 0F BLACK CUMIN (NIGELLA SATIVA L.) SEED EXTRACT ON THE SEED GERMINATION, SEEDLING GROWTH, MITOTIC ACTIVITY AND CHROMOSOMAL ABBERATIONS OF ALLIUM CEPA L. UNDER SALINE CONDITION Dilek Çavuşoğlu 1 , Kürşat Çavuşoğlu 2 and Selma Tabur 2 1 Süleyman Demirel University, Atabey Vocational School, Department of Food Processing, Isparta, Turkey 2 Süleyman Demirel University, Faculty of Arts and Science, Department of Biology, Isparta, Turkey E-Mail: dilekcavusoglu@sdu.edu.tr ABSTRACT In this work, the effects of black cumin seed extract (BCSE) on the seed germination, seedling growth (radicle length, radicle number and fresh weight), mitotic activity and chromosomal aberrations of Allium cepa L. germinated under both normal conditions and salt stress were studied. The radicle number of the seeds germinated in the medium with BCSE alone partly reduced in comparison with ones of the control seeds germinated in distilled water medium while their germination percentage, radicle length and fresh weight statistically showed the same values as the control. Furthermore, the mitotic index in root tip meristems of A. cepa seeds germinated in the medium with BCSE alone demonstrated a significant decrease according to ones of the control seeds germinated in distilled water medium while the frequency of chromosomal aberrations exhibited a significant increase according to the control. On the other hand, salt stress considerably inhibited the seed germination and seedling growth of A. cepa. Moreover, it markedly decreased the mitotic index in root tip meristems of the seeds and increased the number of chromosomal aberrations. Whereas, the inhibitive effects of salt on the seed germination and seedling growth were dramatically alleviated in varying degrees by BCSE application. But, it was ineffective in reducing of salt damage on the mitotic activity and chromosomal aberrations. Keywords: black cumin, chromosomal aberrations, mitotic index, salt stress, seed germination, seedling growth. INTRODUCTION Accumulation of excess salts in the root zone resulting in partial or complete loss of soil productivity is a worldwide phenomenon. Approximately 20 % of the world’s cultivated land, which accounts for over 6 % of the world total area, is threatened by salinity. 500.000 hectares of agricultural areas in Turkey are affected by salinization (FAO 2015). Salt affected soil in Turkey is especially located in the Central South, Central North and Mediterranean region (Haktanır et al. 2012). The salt affected soils contain excess salts which affect plants by decreasing the osmotic potential of the soil solution (osmotic stress), interfering with normal nutrient uptake, inducing ionic toxicity, and associating nutrient imbalances (Dudley 1992, An et al. 2003). Processes such as seed germination, seedling growth and vigour, vegetative growth, flowering and fruit set are adversely affected by high salt concentration, ultimately causing diminished economic yield and also quality of production (Sairam and Tyagi 2004). The most efficient way to minimize the detrimental effects of salinity on plant breeding is the development of the varieties with high salinity tolerance. Hence, researchers have used various plant growth regulators and vitamins to reduce or eradicate negative effects of salinity on seed germination (Duan et al. 2008, Emam and Helal 2008), seedling growth (Çavuşoğlu et al. 2013, 2014) and mitotic activity (Tabur and Demir 2009, 2010a, b). In addition, most researchers agree that the best way to proceed with breeding would be via pyramiding different useful physiological traits. However, in spite of substantial efforts, the outcome are still disappointingly poor, due to the physiological and genetic complexity of this trait, the lack of reliable screening tools and most importantly the lack of a comprehensive understanding of the mechanisms behind salinity tolerance (Zhu et al. 2015). Recently, some plant extracts have also been begun to using for decrease the toxicity of various abiotic agents such as heavy metal, some chemical agents and salinity (Babu and Maheswari 2006, Mohamed 2013). For thousands of years, medical plants have been the most important source of live saving drugs for the majority of the world population. Nigella sativa L. (Ranunculaceae), an annual herbaceous plant, is commonly known as Upakunchika, Ajaji, Kalvanjika, Kalika, Kalaunji, Black seed and Black cumin. N. sativa is native to southern Europe, North Africa, south and southwest Asia (Landa et al. 2006, Padhye et al. 2008). Black cumin (N. sativa) seeds contain proteins, carbohydrates, and fixed oil (84 % fatty acids, including linolenic and oleic) and volatile oils, alkaloids, saponins, crude fibre, as well as minerals, such as calcium, iron, sodium and potassium (Gali-Muhtasib et al. 2006, Abbas Ali et al. 2012). Black cumin seed extract (BCSE) is recognized for traditional healing and as food additive in many cultures with no reported harmful effect (Hamid 2012). It is determined that intact black cumin seeds or their extracts have analgesic, antidiabetic, antihistaminic, antihypertensive, anti-inflammatory, antifungal, antimicrobial, antitumor and insect repellent effects (Siddiqui and Sharma 1996, Worthen et al. 1998, Khan et al. 2003). The Allium test has important advantages (Rank 2003, Kuras et al. 2006) and has been used for many years