Impacts of smoke treatments on germination of cold-stratified seeds in medicinal-rangeland plant Ferula ovina Boiss. (Apiaceae)
Subject Areas : GeneticSanaz Zardari 1 , Farshid Ghaderi-far 2 , Hamid Reza Sadeghipour 3 , ebrahim zeinali 4 , Elias Soltani 5
1 - Department of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
2 - Department of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
3 - Department of Biology, Golestan University, Gorgan, Iran
4 - Department of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
5 - Department of Agronomy and Plant Breeding Sciences, Aboureihan Campus University of Tehran, Tehran, Iran
Keywords: Apiaceae, Karrikin, Smoke aerosol, Smoke extract,
Abstract :
Ferula ovina Boiss. (Apiaceae) is a perennial rangeland medicinal plant found in the mountainous area of Iran. Due to overexploitation, climate changes in the area, and seed dormancy at time of maturity, the population of this species is being reduced. Accordingly, in the present study the effects of smoke treatments (aerosol smoke and two methods of smoke extract preparation) were investigated on seed germination characteristics of this plant after varying periods of cold stratification including 0, 7, 15, and 30 days. Findings suggested that cold stratification changed significantly the level of seed dormancy and increased the rate and percentage of seed germination. Furthermore, aerosol smoke applied after cold stratification increased the rate and percentage of seed germination. The greatest increase in germination percentage compared to control (20%) was observed in seeds that had been cold-stratified for 7 days and were exposed to aerosol smoke for two minutes. Smoke extracts with concentrations (0.001 - 0.01 v/v) prepared by the two methods also increased the germination of cold stratified seeds so that the maximum percentage of germination (80%) was obtained for seeds cold stratified for 30 days and treated with 0.001 dilution of charred straw solution. However, undiluted smoke water decreased the percentage of seed germination after 0 and 30 days of cold stratification and led to abnormal seedling development. In general, the results of this study demonstrated that smoke treatments improve seed germination percentage and speed of cold stratified Ferula ovina seeds.
Amooaghaei, R. (2006). Effect of light, cold and seed age on seed germination of Ferula ovina. Science and Technology of Agriculture and Natural Resources. 10: 289- 297.
Amooaghaei, R. (2007). The effect of GA3 and moist-chilling on seed dormancy breaking of Ferula ovina Boiss. Journal of Science and Technology of Agriculture and Natural Resources. 40: 471-481.
Amooaghaie, R. (2009). The effect mechanism of moist-chilling and GA3 on seed germination and subsequent seedling growth of Ferula ovina Boiss. The Open Plant Science Journal. 3: 22- 28.
Aqel, M., Al-Khalili, S. and Afifi, F. (1992). Relaxing effect of Ferula ovina extract on uterine smooth muscle of rat and guinea pig. International Journal of Pharmacogn. 30(1): 76-80.
Azhir, F. and Shahmoradi, A.A. (2007). Autecology of Ferula ovina Boiss. in Tehran province. Iranian Journal of Range and Desert Research. 14 (3): 359- 367.
Baldos, O.C. and De Frank, J. (2015). Germination response of dormant Tanglehead (Heteropogon contortus) seeds to smoke-infused water and the smoke-associated stimulatory compounds, karrikinolide and cyanide. Hortscience. 3:421–429.
Baskin, C.C., and Baskin, J.M. (2014). Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination, 2nd edition. San Diego: Elsevier/Academic Press.
Baxter, B.J.M. and Van Staden, J. (1994). Plant-derived smoke: an effective seed pre-treatment. Plant Growth Regulation. 14: 279-282.
Bhalla, .P.R., Kochhar, T.S. and. Sabharwal, P.S. (1973). Induction of mitotic abnormalities in Onion root-tips by Tobacco smoke condensate. Cytologia. 38: 707-712.
Briggs, C.L., Morris, E.C. and Stone, G. (2016). Micropylar seed coat restraint and embryonic response to heat shock and smoke control seed dormancy in Grevillea juniperina. Seed Science Research. 26: 111–123.
Burger, B.V., Posta, M., Light, M.E., Kulkarni, M.G., Viviers, M.Z. and Van Staden, J. (2018). More butenolides from plant-derived smoke with germination inhibitory activity against karrikinolide. South African Journal of Botany. 115: 256- 263
Catav, S.S., Bekar, I., Ates, B.S., Ergan, G., Oymak, F., Ulker, E.D., and Tavsanoglu, C. (2012). Germination response of five eastern Mediterranean woody species to smoke solution derived from various plant. Turkish Journal of Botany. 36: 480–487.
Cavieres, L.A. and Arroyo, M.T.K. (2000). Seed germination response to cold stratification period and thermal regime in Phacelia secunda (Hydrophyllaceae). Plant Ecology. 149: 1–8.
De Lange, J.H. and Boucher, C. (1990). Autecological studies on Audouinia capitata Bruniaceae. I. Plant-derived smoke as a seed germination cue. South African Journal of Botany. 56: 700-703.
Dixon, K.W., Roche, S. and Pate, J.S. (1995). The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants. Oecologia. 101: 185-192.
Fasih, M. and Tavakkol Afshari, R. (2018). The morphophysiological dormancy of Ferula ovina seeds is alleviated by low temperature and hydrogen peroxide. Seed Science Research. 28 (1):52-62.
Flematti, G.R., Ghisalberti, E.L., Dixon, K.W. and Trengove, R.D. (2004). A compound from smoke that promotes seed germination.Science. 305: 977-977.
Flematti, G.R., Ghisalberti, E.L., Dixon, K.W. and Trengove, R.D. (2009). Identification of alkyl substituted 2 H-furo [2, 3-c] pyran-2-ones as germination stimulants present in smoke. Journal of Agriculture and Food Chemestry.57: 9475-9480.
Flematti, G.R., Goddard-Borger, E.D., Merritt, D.J., Ghisalberti, E.L., Dixon, K.W. and Trengove, R.D. (2007). Preparation of 2H-furo 2,3-c pyran-2-one derivatives and evaluation of their germination-promoting activity. Journal of Agriculture and Food Chemestry. 55:2189–2194.
Flematti, G.R., Scaffidi, A., Dixon, K.W., Smith, S.M., and Ghisalberti, E.L. (2011). Production of the seed germination stimulant karrikinolide from combustion of simple carbohydrates. Journal of Agriculture and Food Chemestry. 59:1195–1198.
Ghaderi- Far, F. and Soltani, A. (2017). Seed testing and control. Mashhad University publication.
Ghaderi- Far, F., Alimagham, S.M., Kameli, A.M., and Jamali, M. (2012). Isabgol (Plantago ovata Forsk) seed germination and emergence as affected by environmental factors and planting depth. International Journal of Plant Production. 6: 185-194.
Govindaraj, M., Masilamani, P., Albert, V.A. and Bhaskaran, M. (2016). Plant derived smoke stimulation for seed germination and enhancement of crop growth: A review. Agricultural Reviews. 2: 87-100.
Iqbal, M., Asif, S., Ilyas, N., Raja, N.I., Hussain, M., Shabir, S., Ashraf Faz, M.N. and Rauf, A. (2016). Effect of plant derived smoke on germination and post germination expression of Wheat (Triticum aestivum L.). American Journal of Plant Sciences. 7: 806-813.
Iranshahi, M , Famili, A. (Pharm. D.), Bassarello, C., Piacente, S. and Pizza, C. (2010). Purification and structure elucidation of compounds from the roots of Ferula ovina Boiss. Journal of Medicinal Plants. 4(36): 72- 80.
Kepczynski, J, Cembrowska, D. and van Staden, J. (2010). Releasing primary dormancy in Avena fatua L. caryopses by smoke-derived butenolide. Plant Growth Regulation. 62:85–91.
Keshtkar, H.R., Azarnivand, H., Etemad, V. and Moosavi, S.S. (2008). Seed dormancy-breaking and germination requirements of Ferula ovina and Ferula gummosa. Desert. 13: 45-51
Krock, B., Schmidt, S., Hertweck, C. and Baldwin, I.T. (2002). Vegetation-derived abscisic acid and four terpenes enforce dormancy in seeds of the post-fire annual Nicotiana attenuata. Seed Science Research. 12: 239–252.
Kulkarni, M.G., Sparg, S.G. and Van Staden, J. (2006). Dark conditioning, cold stratification and a smoke-derived compound enhance the germination of Eucomis autumnalis subsp. autumnalis seeds. South African Journal of Botany. 72: 157 – 162
Light, M.E., Burger, B.V., Staerk, D., Kohout, L., and Van Staden, J. (2010). Butenolides from plant-derived smoke: natural plant-growth regulators with antagonistic actions on seed germination. Journal of Natural Products. 73: 267–269.
Lindon, H.L. and Menges, E. (2008). Effects of smoke on seed germination of twenty species of fire-prone habitats in Florida.Castanea. 2: 106-110.
Malek, M., Ghaderi-Far, F. and Gorzin, M. (2018). The effects of smoke and gibberellic acid on dormancy elimination of wild mustard (Sinapis arvensis) seeds in different temperatures. 4th. National seed science and technology conference of Iran. 13- 15 February, Karaj, Iran.
Minorsky, P.V. (2002). Smoke-induced germination. Plant Physiology. 128: 1167–1168.
Moghimi J. (2006). Introduce of some plant species that suitable for reclamation of Iran rangelands. Arvan Press, 669 p. (In Persian).
Mozaffarian V. (1996). A Dictionary of Iranian Plant Names, volume 3. Tehran: Farhang-e Moaser.
Nelson, D.C., Flematti, G.R., Ghisalberti, E.L., Dixon, K.W. and Smith, S.M. (2012). Regulation of seed germination and seedling growth by chemical signals from burning vegetation. Annual Review of Plant Biology.63: 107–130.
Nelson, D.C., Riseborough, J., Flematti, G.R., Stevens, J., Ghisalberti, E.L., Dixon, K.W., and Smith, S.M. (2009). Karrikins discovered in smoke trigger Arabidopsis seed germination by a mechanism requiring gibberellic acid synthesis and light. Plant Physiology. 149: 863–873.
Nikoleava, M.G. (1969). Physiology of deep dormancy in seeds. Izdatel'stvo "Nauka", Leningrad. (Translation from Russian by Z. Shapiro, National Science Foundation, Washington, D.C.).
Norman, M.A. , Plummer, J.A. , Koch, J.M. and Mullins, G.R.(2006). Optimising smoke treatments for jarrah (Eucalyptus marginata) forest rehabilitation.Australian Journal of Botany. 6: 571-581.
Papenfus, H.B., Kulkarni, M.G., Posta, M., Finnie, J.F. and Van Staden, J. (2015). Smoke-isolated Trimethylbutenolide inhibits seed germination of different weed species by reducing amylase activity. Weed Science. 63: 312–320.
Ren, L., Bai, Y. and Reaney, M. (2017). Evidence of different compounds in smoke derived from Legume sand grasses acting on seed germination and seedling emergence. Seed Science Research. 27: 154–164.
Roche, S., Koch, J.M. and Dixon, K.W. (1997). “Smoke enhanced seed germination for mine rehabilitation in the southwest of Western Australia,” Restoration Ecology. 3: 191– 203.
Safaian, N. and Shokri, M. (1993). Botanical and ecological study of species of the genus Ferula (Medicinal Plants) in Mazandaran province. Acta Horticulture. 333: 159-167.
Scaffidi, A., Flematti, G.R., Nelson, D.C., Dixon, K.W., Smith, S.M. and Ghisalberti, E.L. (2011). The synthesis and biological evaluation of labelled karrikinolides for the elucidation of the mode of action of the seed germination stimulant. Tetrahedron. 67:152–157.
Schmitz, N., Abrams, S.R., and Kermode, A.R. (2002). Changes in ABA turnover and sensitivity that accompany dormancy termination of yellow-cedar (Chamaecyparis nootkatensis) seeds. Journal of Experimental Botany. 53: 89-101.
Schwachtje, J., and Baldwin, I.T. (2004). Smoke exposure alters endogenous gibberellin and abscisic acid pools and gibberellin sensitivity while eliciting germination in the post-fire annual, Nicotiana attenuate. Seed Science Research. 14: 51–60.
Shayanfar, A. (2017). Studying genetic variation of secondary dormancy and oilseed rape bank persistence. Ph.D Dissertation, Gorgan University of Agricultural Sciences and Natural Resources, Iran.
Silva E.A.A., Toorop, P.E., van Aelst, A.C., and Hilhorst H.W.M. (2004). ABA regulates embryo growth potential and endosperm cap weakening during coffee (Coffea arabica cv. Rubi) seed germination. Planta, 220: 251–261.
Soltani, E.,F. Ghaderi-Far, C.C. Baskin and Baskin, J.M. (2015). Problems with using mean germination time to calculate rate of seed germination. Australian Journal of Botany. 8: 631-635.
Sparg, S.G., Kulkarni, M.G. and Van Staden, J. (2006). Aerosol smoke and smoke-water stimulation of seedling vigor of a commercial maize cultivar.Crop Science. 46:1336-1340.
Stokes, P. (1953a). A physiological study of embryo development in Heracleum sphondylium L. III. The effect of temperature on metabolism. Annual Botany. 17:157- 169.
Stokes, P. (1953b). The stimulation of growth by low temperature in embryos of Heracleum sphondylium L. Journal of Experimental Botany. 4: 222-234.
Stokes, P. (1952). A physiological study of embryo development in Heracleum sphondylium L. II. The effect of temperature on after-ripening. Annual Botany. 16: 571- 576.
Van Staden, J., Jager, A.K. and Strydom, A. (1995). Interaction between a plant-derived smoke extract, light and phytohormones on the germination of light-sensitive lettuce seeds. Plant Growth Regulation. 17: 213–218.
Van Staden, J., Jager, A.K., Light, M.E., Burger, B.V., Brown, N.A.C. and Thomas, T.H. (2004). Isolation of the major germination cue from plant-derived smoke. South African Journal of Botany. 70: 654-659.
Van Staden, J., Sparg, S.G., Kulkarni, M.G. and Light, M.E. (2006). Post-germination effects of the smoke-derived compound 3-methyl-2H-furo [2, 3-c] pyran-2-one and its potential as a preconditioning agent.Field Crops Research. 98: 98-105.
Zuloaga-Aguilar, S., Briones, O., and Orozco-Segovia, A. (2011). Seed germination of montane forest species in response to ash, smoke and heat shock in Mexico. Acta Oecologica. 37: 256-262.
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Amooaghaei, R. (2006). Effect of light, cold and seed age on seed germination of Ferula ovina. Science and Technology of Agriculture and Natural Resources. 10: 289- 297.
Amooaghaei, R. (2007). The effect of GA3 and moist-chilling on seed dormancy breaking of Ferula ovina Boiss. Journal of Science and Technology of Agriculture and Natural Resources. 40: 471-481.
Amooaghaie, R. (2009). The effect mechanism of moist-chilling and GA3 on seed germination and subsequent seedling growth of Ferula ovina Boiss. The Open Plant Science Journal. 3: 22- 28.
Aqel, M., Al-Khalili, S. and Afifi, F. (1992). Relaxing effect of Ferula ovina extract on uterine smooth muscle of rat and guinea pig. International Journal of Pharmacogn. 30(1): 76-80.
Azhir, F. and Shahmoradi, A.A. (2007). Autecology of Ferula ovina Boiss. in Tehran province. Iranian Journal of Range and Desert Research. 14 (3): 359- 367.
Baldos, O.C. and De Frank, J. (2015). Germination response of dormant Tanglehead (Heteropogon contortus) seeds to smoke-infused water and the smoke-associated stimulatory compounds, karrikinolide and cyanide. Hortscience. 3:421–429.
Baskin, C.C., and Baskin, J.M. (2014). Seeds: Ecology, Biogeography and Evolution of Dormancy and Germination, 2nd edition. San Diego: Elsevier/Academic Press.
Baxter, B.J.M. and Van Staden, J. (1994). Plant-derived smoke: an effective seed pre-treatment. Plant Growth Regulation. 14: 279-282.
Bhalla, .P.R., Kochhar, T.S. and. Sabharwal, P.S. (1973). Induction of mitotic abnormalities in Onion root-tips by Tobacco smoke condensate. Cytologia. 38: 707-712.
Briggs, C.L., Morris, E.C. and Stone, G. (2016). Micropylar seed coat restraint and embryonic response to heat shock and smoke control seed dormancy in Grevillea juniperina. Seed Science Research. 26: 111–123.
Burger, B.V., Posta, M., Light, M.E., Kulkarni, M.G., Viviers, M.Z. and Van Staden, J. (2018). More butenolides from plant-derived smoke with germination inhibitory activity against karrikinolide. South African Journal of Botany. 115: 256- 263
Catav, S.S., Bekar, I., Ates, B.S., Ergan, G., Oymak, F., Ulker, E.D., and Tavsanoglu, C. (2012). Germination response of five eastern Mediterranean woody species to smoke solution derived from various plant. Turkish Journal of Botany. 36: 480–487.
Cavieres, L.A. and Arroyo, M.T.K. (2000). Seed germination response to cold stratification period and thermal regime in Phacelia secunda (Hydrophyllaceae). Plant Ecology. 149: 1–8.
De Lange, J.H. and Boucher, C. (1990). Autecological studies on Audouinia capitata Bruniaceae. I. Plant-derived smoke as a seed germination cue. South African Journal of Botany. 56: 700-703.
Dixon, K.W., Roche, S. and Pate, J.S. (1995). The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants. Oecologia. 101: 185-192.
Fasih, M. and Tavakkol Afshari, R. (2018). The morphophysiological dormancy of Ferula ovina seeds is alleviated by low temperature and hydrogen peroxide. Seed Science Research. 28 (1):52-62.
Flematti, G.R., Ghisalberti, E.L., Dixon, K.W. and Trengove, R.D. (2004). A compound from smoke that promotes seed germination.Science. 305: 977-977.
Flematti, G.R., Ghisalberti, E.L., Dixon, K.W. and Trengove, R.D. (2009). Identification of alkyl substituted 2 H-furo [2, 3-c] pyran-2-ones as germination stimulants present in smoke. Journal of Agriculture and Food Chemestry.57: 9475-9480.
Flematti, G.R., Goddard-Borger, E.D., Merritt, D.J., Ghisalberti, E.L., Dixon, K.W. and Trengove, R.D. (2007). Preparation of 2H-furo 2,3-c pyran-2-one derivatives and evaluation of their germination-promoting activity. Journal of Agriculture and Food Chemestry. 55:2189–2194.
Flematti, G.R., Scaffidi, A., Dixon, K.W., Smith, S.M., and Ghisalberti, E.L. (2011). Production of the seed germination stimulant karrikinolide from combustion of simple carbohydrates. Journal of Agriculture and Food Chemestry. 59:1195–1198.
Ghaderi- Far, F. and Soltani, A. (2017). Seed testing and control. Mashhad University publication.
Ghaderi- Far, F., Alimagham, S.M., Kameli, A.M., and Jamali, M. (2012). Isabgol (Plantago ovata Forsk) seed germination and emergence as affected by environmental factors and planting depth. International Journal of Plant Production. 6: 185-194.
Govindaraj, M., Masilamani, P., Albert, V.A. and Bhaskaran, M. (2016). Plant derived smoke stimulation for seed germination and enhancement of crop growth: A review. Agricultural Reviews. 2: 87-100.
Iqbal, M., Asif, S., Ilyas, N., Raja, N.I., Hussain, M., Shabir, S., Ashraf Faz, M.N. and Rauf, A. (2016). Effect of plant derived smoke on germination and post germination expression of Wheat (Triticum aestivum L.). American Journal of Plant Sciences. 7: 806-813.
Iranshahi, M , Famili, A. (Pharm. D.), Bassarello, C., Piacente, S. and Pizza, C. (2010). Purification and structure elucidation of compounds from the roots of Ferula ovina Boiss. Journal of Medicinal Plants. 4(36): 72- 80.
Kepczynski, J, Cembrowska, D. and van Staden, J. (2010). Releasing primary dormancy in Avena fatua L. caryopses by smoke-derived butenolide. Plant Growth Regulation. 62:85–91.
Keshtkar, H.R., Azarnivand, H., Etemad, V. and Moosavi, S.S. (2008). Seed dormancy-breaking and germination requirements of Ferula ovina and Ferula gummosa. Desert. 13: 45-51
Krock, B., Schmidt, S., Hertweck, C. and Baldwin, I.T. (2002). Vegetation-derived abscisic acid and four terpenes enforce dormancy in seeds of the post-fire annual Nicotiana attenuata. Seed Science Research. 12: 239–252.
Kulkarni, M.G., Sparg, S.G. and Van Staden, J. (2006). Dark conditioning, cold stratification and a smoke-derived compound enhance the germination of Eucomis autumnalis subsp. autumnalis seeds. South African Journal of Botany. 72: 157 – 162
Light, M.E., Burger, B.V., Staerk, D., Kohout, L., and Van Staden, J. (2010). Butenolides from plant-derived smoke: natural plant-growth regulators with antagonistic actions on seed germination. Journal of Natural Products. 73: 267–269.
Lindon, H.L. and Menges, E. (2008). Effects of smoke on seed germination of twenty species of fire-prone habitats in Florida.Castanea. 2: 106-110.
Malek, M., Ghaderi-Far, F. and Gorzin, M. (2018). The effects of smoke and gibberellic acid on dormancy elimination of wild mustard (Sinapis arvensis) seeds in different temperatures. 4th. National seed science and technology conference of Iran. 13- 15 February, Karaj, Iran.
Minorsky, P.V. (2002). Smoke-induced germination. Plant Physiology. 128: 1167–1168.
Moghimi J. (2006). Introduce of some plant species that suitable for reclamation of Iran rangelands. Arvan Press, 669 p. (In Persian).
Mozaffarian V. (1996). A Dictionary of Iranian Plant Names, volume 3. Tehran: Farhang-e Moaser.
Nelson, D.C., Flematti, G.R., Ghisalberti, E.L., Dixon, K.W. and Smith, S.M. (2012). Regulation of seed germination and seedling growth by chemical signals from burning vegetation. Annual Review of Plant Biology.63: 107–130.
Nelson, D.C., Riseborough, J., Flematti, G.R., Stevens, J., Ghisalberti, E.L., Dixon, K.W., and Smith, S.M. (2009). Karrikins discovered in smoke trigger Arabidopsis seed germination by a mechanism requiring gibberellic acid synthesis and light. Plant Physiology. 149: 863–873.
Nikoleava, M.G. (1969). Physiology of deep dormancy in seeds. Izdatel'stvo "Nauka", Leningrad. (Translation from Russian by Z. Shapiro, National Science Foundation, Washington, D.C.).
Norman, M.A. , Plummer, J.A. , Koch, J.M. and Mullins, G.R.(2006). Optimising smoke treatments for jarrah (Eucalyptus marginata) forest rehabilitation.Australian Journal of Botany. 6: 571-581.
Papenfus, H.B., Kulkarni, M.G., Posta, M., Finnie, J.F. and Van Staden, J. (2015). Smoke-isolated Trimethylbutenolide inhibits seed germination of different weed species by reducing amylase activity. Weed Science. 63: 312–320.
Ren, L., Bai, Y. and Reaney, M. (2017). Evidence of different compounds in smoke derived from Legume sand grasses acting on seed germination and seedling emergence. Seed Science Research. 27: 154–164.
Roche, S., Koch, J.M. and Dixon, K.W. (1997). “Smoke enhanced seed germination for mine rehabilitation in the southwest of Western Australia,” Restoration Ecology. 3: 191– 203.
Safaian, N. and Shokri, M. (1993). Botanical and ecological study of species of the genus Ferula (Medicinal Plants) in Mazandaran province. Acta Horticulture. 333: 159-167.
Scaffidi, A., Flematti, G.R., Nelson, D.C., Dixon, K.W., Smith, S.M. and Ghisalberti, E.L. (2011). The synthesis and biological evaluation of labelled karrikinolides for the elucidation of the mode of action of the seed germination stimulant. Tetrahedron. 67:152–157.
Schmitz, N., Abrams, S.R., and Kermode, A.R. (2002). Changes in ABA turnover and sensitivity that accompany dormancy termination of yellow-cedar (Chamaecyparis nootkatensis) seeds. Journal of Experimental Botany. 53: 89-101.
Schwachtje, J., and Baldwin, I.T. (2004). Smoke exposure alters endogenous gibberellin and abscisic acid pools and gibberellin sensitivity while eliciting germination in the post-fire annual, Nicotiana attenuate. Seed Science Research. 14: 51–60.
Shayanfar, A. (2017). Studying genetic variation of secondary dormancy and oilseed rape bank persistence. Ph.D Dissertation, Gorgan University of Agricultural Sciences and Natural Resources, Iran.
Silva E.A.A., Toorop, P.E., van Aelst, A.C., and Hilhorst H.W.M. (2004). ABA regulates embryo growth potential and endosperm cap weakening during coffee (Coffea arabica cv. Rubi) seed germination. Planta, 220: 251–261.
Soltani, E.,F. Ghaderi-Far, C.C. Baskin and Baskin, J.M. (2015). Problems with using mean germination time to calculate rate of seed germination. Australian Journal of Botany. 8: 631-635.
Sparg, S.G., Kulkarni, M.G. and Van Staden, J. (2006). Aerosol smoke and smoke-water stimulation of seedling vigor of a commercial maize cultivar.Crop Science. 46:1336-1340.
Stokes, P. (1953a). A physiological study of embryo development in Heracleum sphondylium L. III. The effect of temperature on metabolism. Annual Botany. 17:157- 169.
Stokes, P. (1953b). The stimulation of growth by low temperature in embryos of Heracleum sphondylium L. Journal of Experimental Botany. 4: 222-234.
Stokes, P. (1952). A physiological study of embryo development in Heracleum sphondylium L. II. The effect of temperature on after-ripening. Annual Botany. 16: 571- 576.
Van Staden, J., Jager, A.K. and Strydom, A. (1995). Interaction between a plant-derived smoke extract, light and phytohormones on the germination of light-sensitive lettuce seeds. Plant Growth Regulation. 17: 213–218.
Van Staden, J., Jager, A.K., Light, M.E., Burger, B.V., Brown, N.A.C. and Thomas, T.H. (2004). Isolation of the major germination cue from plant-derived smoke. South African Journal of Botany. 70: 654-659.
Van Staden, J., Sparg, S.G., Kulkarni, M.G. and Light, M.E. (2006). Post-germination effects of the smoke-derived compound 3-methyl-2H-furo [2, 3-c] pyran-2-one and its potential as a preconditioning agent.Field Crops Research. 98: 98-105.
Zuloaga-Aguilar, S., Briones, O., and Orozco-Segovia, A. (2011). Seed germination of montane forest species in response to ash, smoke and heat shock in Mexico. Acta Oecologica. 37: 256-262.