The effect of salinity on germination, emergence, seed yield and biomass of black cumin

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

Sensitivity of Seed Germination to Salt Stress in Black Cumin (Nigella sativa L.)

“…The mean germination time increased with the reduction of water potential, especially at the lower temperature of 15 °C (Table 1). Similar effects were observed in seed germination, seedling emergence and seedling survival of Nigella sativa in the laboratory and the field (Faravani et al, 2013). Moreover, our results were in agreement with the findings of Javadi et al (2014) and Ahmadian et al (2015) who found that high levels of salinity can significantly inhibit seed germination in black cumin.…”

“…In particular, increasing of salinity until 16 dS m -1 reduced the seed germination percentage of Nigella sativa and no germination occurred in the highest salinity stress of 20 dS m -1 (Javadi et al, 2014). Germination percentage drastically declined and was delayed with increase of osmotic stress due to NaCl in MPa lower than -0.9 (Ahmadian et al, 2015) and in salinity stress below 21 dS m -1 (Faravani et al, 2013). Conversely, as reported by Hajar et al (1996) the seeds showed a germination rate of 95% to 82% in less than a week in salinity 150 ml mol at a constant temperature of 25 °C, and suggest that black cumin is a salt tolerant plant.…”

“…In particular, increasing salinity reduced the seed germination percentage of Nigella sativa and no germination occurred in the highest salinity stress (Faravani et al, 2013;Javadi et al, 2014;Ahmadian et al, 2015). However, another study reported a decrease in root length and shoot length of Nigella sativa seedlings by 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 and suggests that black cumin is a salt tolerant plant (Hajar et al, 1996).…”

“…Saline soil causes physiological and metabolic disorders in seed germination, survival percentage, morphological characteristics of plants, affecting development, growth, yield, and quality of plants (Al-Jassir, 1992;Faravani et al, 2013;Khalid 2015).…”

Seed germination and seedling growth of oilrape under saline stress conditions

“…Germination speed depended both on the concentration of NaCl in the medium, and on the variety. Negative effect of NaCl on the germination speed was determined by Faravani et al (2013) in his studies. Draught (Shahverdikadi et al, 2011) and temperature (Gairola et al, 2011) also exert great inffluence on the speed of germination.…”