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نوع مقاله : مقالات پژوهشی

نویسندگان

1 مجتمع آموزش عالی تربت جام

2 مجتمع آموزش عالی تربت جام،

چکیده

جوانه­زدن کامل و یکنواخت که شرط لازم برای استقرار گیاهچه­های قوی و نهایتاً تولید موفق یک محصول است، تحت تاثیر عوامل مختلف محیطی بویژه حرارت و رطوبت بستر کشت قرار می­گیرد. به منظور مطالعه تأثیر دما و تنش خشکی بر جوانه­زنی بذر هندوانه و کمی سازی پاسخ جوانه­زنی با مدل­های زمان حرارتی-رطوبتی، آزمایشی به صورت فاکتوریل با هفت سطح دما شامل 10، 15، 20، 25، 30، 35 و 40 درجۀ سلسیوس و شش سطح تنش خشکی شامل 0، 25/0-، 5/0-، 75/0-، 0/1- و 25/1- مگاپاسکال انجام شد. نتایج نشان داد بطور متوسط در همۀ سطوح دمایی با کاهش پتانسیل اسمزی، میزان جوانه­زنی کاهش یافت، با این­وجود شدت این کاهش در محدوده حرارتی 25 درجه سانتی­گراد کمتر از دماهای بالاتر و پایین تر آن بود. کمینه و بیشینه دما برای جوانه­زنی هندوانه در روش رگرسیون خطی به ترتیب 7/10 و 0/40 درجه ساتیگراد، و در روش مدل زمان حرارتی 5/11 و  1/40 درجه سانتیگراد برآورد گردید. درجه حرارت مطلوب جوانه­زنی نیز در روش رگرسیون و مدل زمان حرارتی-رطوبتی به ترتیب 3/25 و 2/25 درجه سانتی­گراد برآورد شد. مقدار پتانسیل آب پایه برای جوانه­زنی هندوانه در مدل زمان رطوبتی در درجه حرارت­های مختلف نیز بین 45/0-  تا 23/1- مگاپاسکال محاسبه شد، با این­وجود در مدل زمان حرارتی-رطوبتی مقدار پتانسیل آب آستانه برای جوانه­زنی در دامنه حرارتی پایین تر و بالاتر از حد مطلوب حرارتی بین 1/1- تا 2/1- مگاپاسکال تخمین زده شد. بدین ترتیب نتایج نشان داد که با افزایش حرارت بستر کشت پتانسیل آب پایه برای جوانه­زنی افزایش خواهد یافت. در نهایت نتایج مدل نشان داد که مدل زمان حرارتی-رطوبتی به­خوبی قادر است بیش از 90 درصد تغییرات جوانه­زنی بذر هندوانه را در پاسخ به حرارت و رطوبت کمی کند.

کلیدواژه‌ها

عنوان مقاله [English]

Simulation of Germination Response of Watermelon (Citrullus lanatus Thunb.) to Temperature and Water Potential

نویسندگان [English]

  • Seyyed Farhad Saberali 1
  • Hossein Nastari Nasrabadi 1
  • Zahra Shirmohamadi Ali Akbar Khani 2

1 High Educational Complex of Torbat-e Jam

2 High Educational Complex of Torbat-e Jam

چکیده [English]

 
Introduction: A rapid, complete, and uniform seed germination is important to establish a healthy seedling that is a critical key to successful crop production. Therefore, identification of effective factors on germination and plant response to various conditions are important to use an appropriate agronomic managements. Temperature and water are the most important environmental factors controlling seed germination in plants. The crop growth models are among the most effective tools for using in crop management decisions. The response of seed germination to temperature and water potential can be simulated by thermal time, hydrotime and hydrothermal time models. Regarding the importance of watermelon production in Iran, this study was conducted to determine the cardinal temperatures of germination in watermelon plant, and also to quantify its germination in response to the temperature and water potential interaction. .
Materials and Methods: In order to investigate the effects of temperature and drought stress on seed germination and quantifying the germination responses; a factorial experiment was conducted with seven  levels  of temperature including  10, 15, 20, 25, 30, 35 and 40 °C and  the  six levels of water potential including 0, –0.25, –0.5, −0.75, –1.0, and –1.25 MPa, respectively. A Ψ of 0 MPa was obtained using distilled water. The negative Ψ levels were prepared by polyethylene glycol (PEG 6000; Merck, Germany) according to Michel and Kaufman (1973). For each treatment, four 25-seed replicates were placed in 9-cm petri dishes containing one disk of Whatman No. 1 filter paper, with 7 mL of test solutions. Cumulative germination percentage was transformed to probit regression against time log (Finney, 1971; Steinmaus et al., 2000), and the time taken for cumulative germination (tg) to reach subpopulation percentiles (10–90%) was estimated from this function according to Steinmaus et al. (2000). Then the germination rates (GR) were calculated as the inverses of the germination times for each percentile at each T or Ψ. The preliminary estimation of the parameters in the TT, and HT models were obtained by plotting GR versus T and Ψ for each percentile. Then using repeated probit analysis developed by Ellis et al. (1986), the exact parameters for the TT, HT and HTT models were determined for the whole seed population. All statistical procedure were done by SAS and Excel software, and the figures were drawn by SigmaPlot10 software.
Result and Discussion: The analysis of variance showed that the temperature, water potential and their interaction had significant effect on the germination percentage of the watermelon plant. Seed germination of watermelon was about 96 % under the optimal conditions. However, the germination ability was affected by the temperature and water potential of the seedbed. The results showed that the germination was decreased by decreasing water potential, at all temperature levels. The seeds of watermelon germinated over a range of water potentials from 0 to -1 MPa. Furthermore, the lowest germination loss associated with decreasing water potential observed at temperature range of 20-30 °C (compared to temperatures below and above this range). The maximum percentage of germination was recorded at 20-30 °C, while no seeds germinated at 10 and 40 ° C. The results also showed that the highest germination rate was obtained at 25 °C and the germination rate decreased at lower and higher temperature than this range. While watermelon seeds were grown under no water stress condition, the estimated base and ceiling temperatures of germination by a linear regression method were 10.7 and 40.0 °C, respectively. However thermal time model was used, but the base and the maximum temperatures were estimated as 11.5 and 40.1 °C, respectively. Furthermore, an optimum temperature of 25.2 °C was predicted by hydrothermal time model for watermelon germination. The results showed that the base temperature and median thermal time to germination were varied with changing water potential. The hydrotime analysis showed that the base water potentials was in a range from -0.45 to -1.23 Mpa, that differed with changing water potential. Watermelon seeds had higher base water potential and also required a longer hydrotime for germination under non-optimal temperature. Hydrothermal time analysis showed that seed germination responses to temperature and water potential might as well quantified by parameters derived from hydrothermal time models (R2= 0.90-0.92). The amount of hydrothermal time required to germinate was 40.5 MPa °C days on the suboptimal and supra optimal temperature ranges. The HTT model showed that the Ψb(50) increased by 0.09 MPa with every degree increase in temperature above optimum temperature.
Conclusions: The thermal time, hydrotime and hydrothermal time models well described germination time course of watermelon seeds in response to temperature and water potential.Thus, the estimated parameters of these germination models allowed us to characterize the germination behavior of watermelon seeds under varying environmental conditions and global warming.

کلیدواژه‌ها [English]

  • Base water potential
  • Hydrohermal time model
  • probit analysis
  • Water stress
1- Akram-Ghaderi F., Soltani A. and Sadeghipour H.R. 2008. Effect of temperature and water potential on germination of medicinal pumpkin (Cucurbita pepo. convar. pepo var. styriaca), black cumin (Nigella sativa L.) and borago (Borago officinalis L.). Journal of Agricultural Sciences and Natural Resources, 15(5): 157-170. (In Persian)
2- Allen P.S., Meyer S.E. and Khan M.A. 2000. Hydrothermal time as a tool in comparative germination studies.p.401–410. In: Black, M., Bradford, K. J., Vazquez-Ramos J. (ed.), Seed biology: Advances and applications, CAB International, Wallingford, UK.
3- Alvarado V., and Bradford K.J. 2002. A hydrothermal time model explains the cardinal temperatures for seed germination. Plant, Cell and Environment, 25: 1061–1069.
4- Argyris J., Dahal P., Hayashi E., Still D.W., and Bradford K.J. 2008. Genetic variation for lettuce seed thermoinhibition is associated with temperature-sensitive expression of abscisic acid, gibberellin, and ethylene biosynthesis, metabolism, and response genes. Plant Physiology 148: 926–947.
5- Bakhshandeh E., Atashi S., Hafeznia M., Pirdashti H., and Teixeira da Silva J. A. 2015. Hydrothermal time analysis of watermelon (Citrullus vulgaris cv. ‘Crimson sweet’) seed germination. Acta Physiologiae Plantarum, 37: 1737-1743.
6- Baskin C.C., and Baskin J. M. 2014. Seeds: Ecology, biogeography and evolution of dormancy and germination (2nd ed). Elsevier/Academic Press, San Diego, California, USA.
7- Bloomberg M., Sedcole J.R., Mason E.G., and Buchan G. 2009. Hydrothermal time germination models for radiata pine (Pinus radiata D.Don). Seed Science Research, 19: 171–182.
8- Bochet E., Garcia-fayos P., Alborch B., and Tormo J. 2007. Soil water availability effects on seed germination account for species segregation in semiarid roadslopes. Plant and Soil, 295: 179 – 191.
9- Boddy L.G., Bradford K.J., and Fischer A.J. 2012. Population-based threshold models describe weed germination and emergence patterns across varying temperature, moisture and oxygen conditions. Journal of Applied Ecology, 49: 1225–1236.
10- Boroumand-Rezazadeh Z., and Koocheki A. 2006. Evaluation of cardinal temperature for three species of medicinal plants, Ajowan (Trachyspermum ammi), Fennel (Foeniculum vulgare) and Dill (Anethum graveolens). BIABAN (Desert Journal), 11, 11-16. (In Persian)
11- Bradford K.J. 1995. Water relations in seed germination. P.351–396. In: Kigel, J., Galili, G. (ed.), Seed Development and Germination. Marcel Dekker, New York,
12- Bradford K.J. 2002. Application of hydrothermal time to quantifying and modeling seed germination and dormancy. Weed Science, 50: 248–260.
13- Cave R.L., Birch C.J., Hammer G.L., Erwin J.E., and Johnston, M.E. 2011. Cardinal temperatures and thermal time for seed germination of brunonia australis (Goodeniaceae) and calandrinia sp. (Portulacaceae). HortScience, 46: 753–758.
14- Cheng Z., and Bradford, K.J. 1999. Hydrothermal time analysis of tomato seed germination responses to priming treatments. Journal of Experimental Botany, 50: 89–99.
15- Chantre G.R., Batlla D., Sabbatini M.R., and Orioli, G. 2009. Germination parameterization and development of an after-ripening thermal-time model for primary dormancy release of Lithospermum arvense seeds. Annals of Botany, 103: 1291–1301.
16- Dahal P. and Bradford K.J. 1994. Hydrothermal time analysis of tomato seed germination at suboptimal temperature and reduced water potential. Seed Science Research 4: 71–80.
17- Demir I., and Mavi K. 2004. The effect of priming on seedling emergence of differentially matured watermelon (Citrullus lanatus Thunb.) seeds. Scientia Horticulturae, 102: 467-473.
18- Ellis R.H, Covell S., Roberts E.H. and Summerfield R.J. 1986. The influence of temperature on seed germination rate in grain legumes. II. Intraspecific variation in chickpea at constant temperatures. Journal of Experimental Botany, 37: 1503–1515.
19- Ertan, S.K. 2010. Modelling the effect of temperature on seed germination in some cucurbits. African Journal of Biotechnology, 9: 1343–1353.
20- Fenner M., and Thompson K. 2005. The ecology of seeds. Cambridge University Press, Edinburgh House, Cambridge. 250 p.
21- Fernandez G., and Johnston M. 1995. Seed vigor testing in lentil, bean, and chickpea. Seed Science and Technology, 23: 617-627.
22- Finney D.J. 1971. Probit analysis. Third edition. Cambridge University Press, Cambridge.
23- Gareca E.E., Vandelook F., Fernandez M., Hermy M., Honnay O., Hermy M., and Honnay, O. 2012. Seed germination, hydrothermal time models and the effects of global warming on a threatened high Andean tree species. Seed Science Research, 22: 287–298.
24- Grundy A.C., Phelps K., Reader R.J., and Burston S. 2000. Modelling the germination of Stellaria media using the concept of hydrothermal time. New Phytologist, 148: 433–444.
25- Gummerson R.J. 1986. The effect of constant temperatures and osmotic potential on the germination of sugerbeet. Journal of Experimental Botany, 37:729–741.
26- Hasandokht M.R. 2012. Vegetables Production Technology. Selsele Press. Tehran. Iran. (in Persian)
27- Holt, J.S. and D.R. Orcutt. 1996. Temperature thresholds for bud sprouting in perennial weeds and seed germination in cotton. Weed Science. 44:523–533.
28- Kebreab E., and Murdoch A.J. 1999. Modelling the effects of water stress and temperature on germination rate of Orobanche aegyptiaca seeds. Journal of Experimental Botany,50 ): 655–664.
29- Kebreab E., and Murdoch A.J.2000. The effect of water stress on the temperature germination rate of Orobanche aegyptiaca seeds. Journal of Experimental Botany, 50): 655-664.
30- Kurtar E.S. 2010. Modelling the effect of temperature on seed germination in some cucurbits. African Journal of Biotechnology, 9: 1343–1353.
31- Larsen S.U., Bailly C., Côme D., and Corbineau F. 2004. Use of the hydrothermal time model to analyse interacting effects of water and temperature on germination of three grass species. Seed Science Research, 14: 35-50.
32- Michel B.E. and Kaufmann M.R. 1973. The osmotic potential of polyethylene glycol 6000. Plant Physiology, 51: 914–916.
33- National Agriculture Statistics. 2017. Ministry of Jahad-Agriculture. Information and Communication Technology Center. Pp 116.
34- Ni B.R., and Bradford K.J. 1992. Quantitative models characterizing seed germination responses to abscisic acid and osmoticum. Plant Physiology, 98: 1057–1068.
35- Nozari-nejad M., Zeinali E., Soltani A., Soltani E., and Kamkar, B. 2013. Quantify wheat germination rate response to temperature and water potential. Journal of Crop production, 6 : 117-135. (in Persian with English abstract)
36- Rowse H.R., and Finch-Savage, W.E. 2003. Hydrothermal threshold models can describe the germination response of carrot (Daucus carota) and onion (Allium cepa) seed populations across both sub- and supra-optimal temperatures. New Phytologist, 158: 101–108.
37- Singh S., Singh P., Sanders D.C., and Wehner, T. C. 2001. Germination of watermelon seeds at low temperature. Report-Cucurbit Genetics Cooperative, 24: 59–64.
38- Steinmaus S.J., Timonthy S.P. and Jodie S.H. 2000. Estimation of base temperature for nine weed species. Journal of Experimental Botany, 51: 275– 286.
39- Wang R., Bai Y., and Tanino, K. 2005. Germination of winterfat (Eurotia lanata Moq.) seeds at reduced water potentials: testing assumptions of hydrothermal time model. Environmental and Experimental Botany, 53: 49–63.
40- Wen-Hu X., Fan Y., Baskin C. C., Baskin J.M., and Wang Y.R. 2015. Comparison of the effects of temperature and water potential on seed germination of Fabaceae species from desert and Subalpine grassland. American Journal of Botany 102 : 649 – 660.
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