THE EFFECT OF SALINITY ON GERMINATION, EMERGENCE, SEED YIELD AND BIOMASS OF BLACK CUMIN
Mahdi Faravani1*, Saeid Davazdeh Emami2, Barat Ali Gholami3 and Akram Faravani4
1
Khorasan Agricultural Research Center, P.O.Box 91735-488, Mashhad, Iran 2Isfahan Agricultural and Natural Resources Research Center
3Khorasan Agricultural Research Center, P.O.Box 91735-488, Mashhad, Iran 4Isalamic Azad University, Mashhad branch
Abstract: Salinity sensitivity of black cumin (Nigella sativa L.) was studied to determine salinity effects on germination, emergence, biological yield, seed yield and plant height. A set of experiments were conducted under completely randomized design in the germinator, greenhouse and field. Seeds of black cumin were grown in a growth chamber irrigated with normal water, electric conductivity (EC) of 0.3 dS m-1 as the control, and treatments amended with NaCl to obtain EC from 3 to 39 dS m-1. Different EC treatments (3–39 dS m-1, 3–15 dS m-1 and 3–9 dS m-1) were applied at different phenological stages of germination, emerging and seed setting, respectively. The effect of salinity on seed germination, germination rate, shoot length, root length, seedling weight, root to shoot ratio and seed vigor was significant at p<0.01. The highest germination rate (94.8%) was observed at the salinity of 3 dS m-1 and no germination was observed at the salinity of 36 dS m-1. Increase of salinity from 0.3 (control) up to 15 dS m-1 significantly (p<0.01) influenced the rate and percentage of emergence. The highest germination percentage (52.5%) and emergence rate (9.2 seedlings per day) were achieved in the control treatment. Seed yield, biomass and plant height were affected significantly (p<0.05) by different salinity treatments. The essential oil percentage was not significantly affected by salinity stress. With an increase in the salinity level from 0.3 to 9 dS m-1, the average seed yield and biological yield were decreased from 105.5 to 40.2 g m-2 and from 550.2 to 268.6 g m-2 respectively.
Key words:Nigella sativa, salinity, growth stages, seed yield.
Introduction
Plants are constantly challenged by various abiotic stresses such as salinity, drought, temperature extremes, heavy metal toxicity, high-light intensity, nutrient
deficiency, UV-B radiation, ozone, etc. Salinity causes substantial losses in the yield and crop quality as well as adaptation (Hasanuzzaman et al., 2012). Water, salinity and nutrient are crop growth-limiting factors but weeds, pests and diseases can decrease the potential of crop yield and they are considered as crop growth reducing factors (Dogliotti et al., 2004; Mehta et al., 2012). Salinity is one of chronic and acute plant stress factors in arid and semiarid regions. The severity of salinity problem is related to environmental constraints. It decreases average yields of major crops by more than 70% and causes a rapid change in the social and economic environment, and together with the deterioration of the natural resource base threatens sustainability of farm systems in these regions. A new strategy for the sustainable production is to use marginal lands and saline water sources safely to supplement all post-sowing irrigations and to lead to a substantial increase in production and water resources conservation by declining groundwater and river flow consumption in agriculture systems (Bone et al., 2012). Reducing the salt content of soil and the number of other suitable plants that can tolerate salt is proposed as a solution to the exploitation of these lands (Lokhande and Suprasanna, 2012). Today, planting salt tolerant species, particularly N2-fixing species, is the most useful approach to rehabilitating salt-affected degraded lands (Soliman et al., 2012; Radić et al., 2007). Nigella sativa belongs to the buttercup family or Ranunculaceae, which is a large family. Globally, it consists of around 1,800 species in about 50 genera. Nigella has 8 herbaceous annual or perennial species in Iran (Mozaffarian, 1992). The genus Nigella represents some 14 species of dicotyledonous flowering plants of Mediterranean and West Asian origin, including some species of commercial importance, for example spices, aromatic, medicinal, and ornamental plants in the world (Landa et al., 2006). The main extracted unsaturated fatty acid of Nigella seed is linoleic acid (52.6%), followed by oleic acid (23.5%), while the main saturated fatty acid is palmitic acid (16%). Triacylglycerols and neutral lipids are found to be the most abounded components recorded to 78.4 and 93.2%. The seed oils, therefore, have the potential for use as domestic and industrial oils and contain considerable amounts of protein (20%) and a high amount of lipid (37%). The seeds are shown to be rich sources of potassium, calcium and sodium and other elements (Ali et al., 2012). Nigella seed extract is recognized for traditional healing and as food additive in many cultures with no reported harmful effect (Hamid, 2012). An investigation was aimed at evaluating the impacts of salinity stress on developmental stages, biological yield and seed yield of Nigella sativa.
Material and Methods
Nigella sativa seeds were collected from Semirom region in Isfahan province,
randomized design with four replications. Salinity treatments were prepared with EC 0.3 dS m-1 (control) and with 3 dS m-1 intervals of using 3 ml of NaCl until high concentrations of salt prevent seeds from germinating. Four samples for each treatment of 100 seeds were placed on a filter paper in Petri dish No. 10, and the seed was treated with Vitavax fungicide. The germinator was adjusted with alternating temperatures of 15/20°C darkness/light, 8/16 hrs at 75% relative humidity. First, they were irrigated with the saline water and then with distilled water. Seedlings were counted after 5 to 10 days from the emergence of the majority of seedlings. Days of germination were calculated based on the emergence of root when its root length was about 2-3 mm (Lin and Xing, 2007). The rate of germination was calculated using the formula (RG)=N1/D1+Ni/Di , where N is a daily increase in seedling number.
Shoot length, root length and seedling weight were measured and seedling vigor was calculated using seedling length × seedling weight (López-Castañedaet al., 1996). The raw numbers (percentages) were analyzed after angular transformation was applied to them. A set of emergence experiments was conducted in 30 cm row spacing under a completely randomized design with four replications and irrigated with salinity water including EC 0.3, 3, 6, 9, 12 and 15 dS m-1 at the farm. The number of emergence seeds was counted per day, which determined the final emergence percentage. Salinity treatments were applied after thinning in the 6–8 leaf stages to reach an equal density in all plots. Weed control was done manually and no herbicides and fertilizer treatments were applied during the growing season. The irrigation was carried out by measuring soil moisture with TDR instrument. Wet and dry biological yield, seed yield per unit area, and plant height were measured after harvesting.
To establish the extraction process of essential oil of Nigella seed, 50 g of seeds after grinding were used for each measurement by applying Clevenger apparatus. Gas chromatography (GC) was used to identify the essential oil compounds.
Statistical analysis of data was performed with the SAS and MSTAT-C softwares. Duncan’s multiple range test was used for multiple comparison procedures.
Results and Discussion
Table 1. Analysis of variance (ANOVA) of seed germination, seed characters, germination and seedling growth in salinity treatments.
Mean squares of measured traits
df Source of
variations Emergence Germination
rate Seedling length Radicle length Seedling weight Seed vigor Root/ shoot 1.034 180.2 2.369** 7.469** 0.2819 0.223** 3.148** 12 Treatment 0.0046 1.772 0.0385 0.1532 0.121 0.0062 0.1052 39 Error **
Significant difference at p<0.01.
There was no significant difference (p<0.05) for the average seed germination between the control and the salinity up to 15 dS m-1 (Table 2). Emergence rate was different from 17.9 seeds per day for the salinity of 6 dS m-1 to 0.0 seeds for the salinity of 33 and 36 dS m-1. The maximum seedling length of 2 cm and the maximum weight of seedling shoot of 0.68 mg were recorded for the salinity of 9 dS m-1. Moreover, the maximum root length was 3.6 cm for the salinity of 3 dS m-1. The highest seed vigor was 0.6 for the salinity of 9 dS m-1. The lowest rates for all the measured characters were observed for the salinity of 27 dS m-1.
Table 2. Means of black seed germination traits in different salinity treatments.
Germination (%) Emergence
rate (seed day-1) Seedling length (mm) Radicle length (mm) Seedling weight (g) Seed vigor (%) Root/ shoot EC
(dS m-1)
93.8ab 94.8a 93.5ab 90.8ab 90.8ab 90.5ab 84.5bc 78.8c 50.8d 25.3e 4.8f 2.0f 0.0f 16.2ab 15.1b 17.9a 16.4ab 11.3c 8.0d 7.4d 6.6d 3.6e 2.0ef 0.2f 0.0f 0.0f 1.4bc 1.6ab 1.9a 2.0a 1.2bcd 1.2bcd 1.8a 1.1dc 0.9d 0.0e 0.0e 0.0e 0.0e 3.0a 3.6a 3.2ab 3.1abc 2.3cde 2.4bcd 2.3de 1.6ef 1.1f 0.0g 0.0g 0.0g 0.0g 0.45ab 0.58a 0.61a 0.68a 0.30bc 0.47ab 0.45ab 0.15cd 0.01d 0.00d 0.00d 0.00d 0.00d 0.39bc 0.52ab 0.55ab 0.60a 0.22d 0.38bc 0.30cd 0.05e 0.00e 0.00e 0.00e 0.00e 0.00e 2.1ab 2.3a 1.7abc 1.6bc 1.9ab 2.0ab 1.2c 1.4bc 1.2c 0.0d 0.0d 0.0d 0.0d 0.3 3 6 9 12 15 18 21 24 27 30 33 36
Means followed by the same letter within a column are not significantly different at P<0.05 according to Duncan’s multiple range test.
increasing salinity to 150 ml mol at a constant temperature of 25°C, with a germination rate of 95 to 82% in less than a week (Hajaret al., 1996).
The effect of salinity on seedling emergence and seedling survival of Nigella
sativa was studied in the field. According to the results, the salinity treatment
significantly decreased (p<0.01) the seedling emergence percentage (52.5%) and emergence rate (9.2 seedling/day) from the control up to 15 ds m-1 where no seedling emergence was observed. High NaCl concentrations caused a significant (p<0.01) reduction in biological yield and seed yield (Table 3). Results indicated that the increased salinity from 0 to 9 dS m-1 caused a significant (p<0.05) reduction from 54.8 to 42.1 cm in plant height, from 105.5 to 40.2 g m-2 in seed yield and from 550.2 to 268.6 g m-2 in biological yield (Table 4). These changes were associated with an increase in the relative water content and the Na+ concentrations (Nia et al., 2012). Saline soil causes physiological and metabolic disturbances in seed germination, survival percentage, morphological characteristics of plants, affecting development, growth, yield, and quality of plants (Al-Jassir, 1992; Rameeh et al., 2012).
Other reports have revealed that growth characters, namely, dry shoot weights, shoot length and biomass decreased with an increase of the salinity levels from 0 to 6 dS/m. Conversely, root length increased with an increase in salinity levels (Hussainet al., 2009).
Table 3. Analysis of variance for the agronomic traits of Nigella sativa grown in different salinity treatments.
Mean squares df
Source of
variations Plant height Seed yield Biological yield
44077**
776 353**
12.63 106.8*
17.55 3
8 Treatment
Error
*
and ** represent a significant difference at p<0.05 and p<0.01, respectively.
Table 4. Comparison of the effects of different salinity levels on agronomic characters of Nigella sativa.
Seed yield (g m-2) Biological yield
(g m-2) Plant height
(cm) EC
(dS m-1)
105.5a 90.2b 72.8c 40.2d 550.2a
470.8b 379.3c 268.6d 54.8a
51.8ab 44.6ab 42.1b 0.3
3 6 9
Based on the results of gas chromatography (GC), 18 different combinations of essential oils in the seeds of Nigella sativa oil were identified, and p-cymene with a rate of 34.5% was the most important (Table 5). The changes of chemical composition of Nigella sativa essential oil were not influenced by different soil salinity and did not show any particular trends.
Table 5. Chemical composition of Nigella sativa essential oil in regard to different soil salinities. Inhibitor index EC0 EC3 EC6 EC9 Essential oil components 384 4.5 4.9 8.8 4.8 α-thujene 398 3.1 1.2 1.2 1.1 α-pinene 469 8 1.1 1.1 7 sabinene 477 4.1 2.2 2.2 3.1 -pinene 485 0 1 2 0 myrcene 558 3.1 8 7 2.1 α-terpinene 575 4.37 5.41 7.26 4.32 p-cymene 610 0 9.1 5.1 limonene 654 2.4 5.1 2.4 7.3 -terpinene 753 0 0 0 6 linalool 456 5.1 0 0 6.1 terpinen-4-ol 1132 1.6 0 0 2.6 carvone 1147 3.4 8.2 5.4 3.4 thymoquinone 1265 2.4 6 5.5 3.5 thymol 1291 4.12 1.9 4.5 1.16 carvacrol 1425 8.1 0 0 9.1 α-longipinene 1571 7.5 0 0 7.6 longifolene 2107 3.1 0 0 2.1 dill apiol Conclusion
Acknowledgments
Agricultural Research, Education and Extension Organization (AREEO) in Iran supported this research. Authors would like to express their gratitude to AREEO for the financial support.
References
Al-Jassir, M.S. (1992): Chemical composition and microflora of black cumin (Nigella sativa L.) seeds growing in Saudi Arabia. Food Chemistry 45:239-242.
Abbas Ali, M., Sayeed, M.A., Shahinur Alam, M., Yeasmin, M.S., Khan, A.M., Muhamad, I.I. (2012): Characteristics of oils and nutrient contents of Nigella sativa Linn. and Trigonella foenum-graecum seeds. Bulletin of the Chemical Society of Ethiopia 26(1):55-64.
Bone, J., Barraclough, D., Eggleton, P., Head, M., Jones, D.T., Voulvoulis, N. (2012): Prioritising soil quality assessment through the screening of sites: the use of publicly collected data. Land Degradation and Development. DOI: 10.1002/ldr.2138
Dogliotti, S., Rossing, W.A.H., van Ittersum, M.K. (2004): Systematic design and evaluation of crop rotations enhancing soil conservation, soil fertility and farm income: a case study for vegetable farms in South Uruguay. Agricultural Systems 80:277-302.
Hajar, A. S., Zidan, M.A., Al Zahrani, H.S. (1996): Effect of salinity stress on the germination, growth and some physiological activities of black cumin (Nigella sativa L.). Arab Gulf Journal of Scientific Research 14:445-454.
Hamid, M.E. (2012): Effect of Nigella sativa L. (black seed) extract on some clinically significant aerobic actinomycetes. Journal of Medicinal Plants Research 6:339-341.
Hasanuzzaman, M., Hossain, M.A., Silva, J.A.T., Fujita, M. (2012): Plant response and tolerance to abiotic oxidative stress: Antioxidant defense is a key factor. In: Venkateswarlu, B., Shanker, A.K., Shanker, C., Maheswari, M. (Eds.), Crop stress and its management: Perspectives and strategies. Springer, Netherlands, pp. 261-315.
Hussain, K., Majeed, A., Nawaz, K., Khizar Hayat, B., Nisar, M.F. (2009): Effect of different levels of salinity on growth and ion contents of black seeds (Nigella sativa L.). Current Research Journal of Biological Sciences 1:135-138.
Landa, P., Marsik, P., Vanek, T., Rada, V., Kokoska, L. (2006): In vitro anti-microbial activity of extracts from the callus cultures of some Nigella species. Biologia 61:285-288.
Lin, D., Xing, B. (2007): Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth. Environmental Pollution 150:243-250.
Lokhande, V.H., Suprasanna, P. (2012): Prospects of halophytes in understanding and managing abiotic stress tolerance. In: Ahmad, P., Prasad, M.N.V. (Eds.), Environmental adaptations and stress tolerance of plants in the era of climate change. Springer, New York, pp. 29-56.
López-Castañeda, C., Richards, R., Farquhar, G., Williamson, R. (1996): Seed and seedling characteristics contributing to variation in early vigor among temperate cereals. Crop Science 36:1257-1266.
Mehta, C., Gupta, V., Singh, S., Srivastava, R., Sen, E., Romantschuk, M., Sharma, A. (2012): Role of microbiologically rich compost in reducing biotic and abiotic stresses. In: Satyanarayana, T. (Ed.), Microorganisms in environmental management. Springer, Netherlands, pp.113-134. Mozaffarian, V. (1992): New species and interesting plant records from Iran. Iranian Journal of
Botany 5:83-90.
Radić, V., Beatović, D., Mrđa J. (2007): Salt tolerance of corn genotypes (Zea mays L.) during germination and later growth. Journal of Agricultural Science (Belgrade) 52:115-120.
Rameeh, V., Cherati, A., Abbaszadeh, F. (2012): Salinity effects on yield, yield components and nutrient ions in rapeseed genotypes. Journal of Agricultural Science (Belgrade) 57:19-29. Soliman, A.S., Shanan, N.T., Massoud, O.N., Swelim, D. (2012): Improving salinity tolerance of
Acacia saligna (Labill.) plant by arbuscular mycorrhizal fungi and Rhizobium inoculation. African Journal of Biotechnology 11:1259-1266.
UTICAJ SALINITETA NA KLIJANJE, NICANJE, PRINOS SEMENA I BIOMASU CRNOG KIMA
Mahdi Faravani1*, Saeid Davazdeh Emami2, Barat Ali Gholami3 i Akram Faravani4
1
Centar za poljoprivredna istraživanja u Korasanu, Mešhed, Iran 2
Istraživački centar za poljoprivredu i prirodne resurse u Isfahanu 3
Centar za poljoprivredna istraživanja u Korasanu, Mešhed, Iran 4
Islamski univerzitet Azad, Ogranak u Mešhedu
R e z i m e
Osetljivost crnog kima (Nigella sativa L.) na salinitet je proučavana kako bi se utvrdio uticaj saliniteta na klijanje, nicanje, biološki prinos, prinos semena i visinu biljke. Niz ogleda je bio sproveden po metodu potpuno slučajnog blok sistema u klijalištu, stakleniku i polju. Semena crnog kima su uzgajana u fitotronu navodnjavanom običnom vodom električne provodljivosti (EP) od 0,3 dS m-1 kao kontrolna varijanta i tretmani sa dodatkom NaCl do postizanja EP od 3 do 39 dS m-1. Tretmani sa različitom EP (3–39 dS m-1, 3–15 dS m-1 i 3–9 dS m-1) su bili primenjeni u različitim fenološkim fazama klijanja, nicanja odnosno ozrnjavanja. Uticaj saliniteta na klijanje semena, brzinu klijanja, dužinu izdanka, dužinu korena, masu klijanca, odnosa korena i izdanka i životnu sposobnost semena je bio značajan pri p<0,01. Najveća brzina klijanja (94,8%) je uočena pri salinitetu od 3 dS m-1, dok klijanje nije zabeleženo pri salinitetu od 36 dS m-1. Povećanje saliniteta od 0,3 (kontrolna varijanta) do 15 dS m-1 značajno (p<0,01) je uticalo na brzinu i procenat nicanja. Najveći procenat klijanja (52,5%) i brzina nicanja (9,2 klijanaca po danu) su postignuti kod kontrolnog tretmana. Tretmani sa različitim salinitetom su značajno (p<0,05) uticali na prinos semena, biomasu i visinu biljke. Salinitet nije značajno (p<0,05) uticao na procenat etarskog ulja. Sa povećenjem nivoa saliniteta od 0,3 do 9 ds m-1, prosečan prinos semena i biološki prinos su se smanjili sa 105,5 na 40,2 g m-2 odnosno sa 550,2 na 268,6 g m-2.
Ključne reči:Nigella sativa, salinitet, faze razvića, prinos semena.
Primljeno: 10. jula 2013. Odobreno: 30. jula 2013.
*
