Document Type : Research Paper


1 M.Sc. Graduated Student, College of Agriculture and Natural Resources, University of Tehran, Karaj – Iran

2 Professor, Department of Agronomy & Plant Breeding, Ferdowsi University of Mashhad, Mashhad – Iran

3 Assistant Professor, College of Aboureyhan, University of Tehran, Pakdasht - Iran

4 Professor, College of Agriculture and Natural Resources, University of Tehran, Karaj - Iran


This study was conducted to evaluate the effects of water potential and temperature on seed germination rate of lemon balm (Mellissa officinalis L.). The seeds were incubated in various temperatures of 20, 23, 25, 27, 30 and 32ºC and water potentials of 0, -0.2, -0.4, -0.6 and -0.8 MPa in three replications. This study was conducted in Seed Laboratory, College of Agriculture and Natural Resources, University of Tehran in Karaj in 2015. Data were analyzed using combined statistical design in a completely randomized design in several places. Segmented function was evaluated to describe cardinal temperatures. The base, optimum and ceiling temperatures of lemon balm were 17.30, 30.9 and 35ºC under optimum conditions of water potential, respectively. The base temperature increased gradually with decreasing water potential and increased to 21.25°C in -0.8 MPa water potential. The optimum temperature decreased to about 28°C by decreasing water potential to -0.6 MPa. Lemon balm seeds did not germinated in 5, 10, 15 and 35°C in any moisture levels. The R2 value of hydrothermal time model was 0.55. The hydrothermal value was 71.41 MPa oday and According to this model seed germination of lemon balm needs to 71.41 MPa oday. The results can be used for future studies on the seed biology and ecology of lemon balm.


1 . اکرم قادری ف (1387) مطالعه نمو کیفیت بذر، جوانه‌زنی، طول عمر و زوال بذر در برخی گیاهان دارویی: کدو تخم‌کاغذی  (Cucurbita pepo. convar. var. styriaca)، سیاه‌دانه (Nigella sativa L.) و گاوزبان (Borago officinalis L.). دانشگاه علوم کشاورزی و منابع طبیعی گرگان. گرگان. رساله دکتری.
2 . امیدبیگی (1392) تولید و فرآوری گیاهان دارویی. جلد سوم، انتشارات به نشر، مشهد. 400 ص.
3 . بخشنده ا، غدیریان ر، گالشی س و سلطانی ا (1390) مدل‌سازی جوانه‌زنی سویا (Glycine max L.) و گاوپنبه (Abutilion thephrasti med.) در واکنش به اثرات متقابل دما و پتانسیل آب. پژوهش‌های تولید گیاهی. 18(2): 48-29.
4 . تبریزی ل، نصیری محلاتی م و کوچکی ع (1383) ارزیابی درجه حرارت‌های حداقل، بهینه و حداکثر جوانه‌زنی اسفرزه و پسیلیوم. پژوهش‌های زراعی ایران. 2(2): 150-143.
5 . سلطانی ا (1390) اکولوژی بانک بذر کلزای خودرو و خردل وحشی: تولید بذر، توزیع عمودی، تغییرات فصلی کمون، جوانه‌زنی و سبز شدن. دانشگاه علوم کشاورزی و منابع طبیعی گرگان. گرگان. رساله دکتری.
6 . سلطانی ا، اویسی م، سلطانی ا، گالشی س، قادری‌فر ف و زینلی ا (1393) مدل‌سازی جوانه‌زنی کلزای خودرو تحت تأثیر دما و پتانسیل آب: مدل هیدروترمال تایم. پژوهش‌ علف‌های هرز. 6(1): 38-23.
7 . سلطانی ا، سلطانی ا، گالشی س، قادری‌فر ف و زینلی ا (1392) مدل‌سازی جوانه‌زنی خردل وحشی تحت تأثیر دما و پتانسیل آب: مدل هیدروترمال تایم. پژوهش‌های تولید گیاهی. 20(1): 34-19.
8 . سلطانی ا، سلطانی ا و اویسی م (1392) مدل‌سازی اثر زوال بذر بر سبز شدن گندم در تنش خشکی: بهینه‌ساز برنامه Germin در پیش‌بینی الگوی سبز شدن. به‌زراعی. 15(2): 160-147.
9 . نوذری‌نژاد م، زینلی ا، سلطانی ا، سلطانی ا و کامکار ب (1392) کمی‌سازی واکنش جوانه‌زنی گندم در واکنش به دما و پتانسیل آب. نشریه تولید گیاهان زراعی. 6(4): 117-135.
10 . Afzal I (2005) Seed enhancements to induced salt tolerance in wheat (Triticum aestivum L.). Agricultural University of Faisalabad, Pakistan, Ph.D. Dissertation.
11 . Alvarado V and Bradford KJ (2002) A hydrothermal time model explains the cardinal temperatures for seed germination. Plant, Cell and Environment. 25(8): 1061-1069.
12 . Ashraf M and Rauf H (2001) Inducing salt tolerate in maize (Zea mays L.) throght seed priming with chloride salts: growth and ion transport at early growth stages. Acta Physiologiae Plantarum. 23: 407-414.
13 . Baskin CC and Baskin JM (2001) Seeds: ecology, biogeography, and evolution of dormancy and germination. Academic Press, San Diego, California, 666p.
14 . Bradford KJ (2002) Applications of hydrothermal time to quantifying and modeling seed germination and dormancy. Weed Science. 50(2): 248-260.
15 . Dahal P and Bradford KJ (1994) Hydrothermal time analysis of tomato seed germination at suboptimal temperature and reduced water potential. Seed Science Reseach. 4(2): 71-80.
16 . Farzane S and Soltani E (2011) Relationship between hydrotime parameters and seed vigor in sugar beet. Seed Science and Biotechnology. 5(1): 7-10.
17 . Gummerson RJ (1986) The effect of constant temperature and osmotic potential on the germination of sugar beet. Journal of Experimental Botany. 37(6): 729-714.
18 . International Seed Testing Association (ISTA) (2009) Handbook of Vigor Test Methods. 3th Ed. Zurich, Switzerland.
19 . Larsen SU, Bailly C, Come 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(1): 35-50.
20 . Mesgaran MB, Mashhadi HR, Alizadeh H, Hunt J, Young KR and Cousens RC (2013) Importance of distribution function selection for hydrothermal time models of seed germination. Weed Research. 53: 89-101.
21 . Michel BE and Kaufmann MR (1973) The osmotic potential of polyethylene glycol 6000. Plant Physiology. 51(5): 914-916.
22 . Soltani A, Galeshi S, Zeinali E and Latifi N (2002) Germination, seed reserve utilization and seedling growth of chickpea as affected by salinity and seed size. Seed Science and Technology. 30: 51-60.
23 . Soltani A, Robertson MJ, Torabi B, Yousefi-Daz M and Sarparast R (2006) Modeling seedling emergence in chickpea as influenced by temperature and sowing depth. Agricultural and Forest Meteorology. 138: 156-167.
24 . Soltani E, Galeshi S, Kamkar B and Akramghaderi F (2008) Modeling Seed Aging Effects on the Response of Germination to Temperature in Wheat. Seed Science and Biotech. 2(1): 32-36.
25 . Soltani E, Soltani A, Galeshi S, Ghaderi-Far F and Zeinali E (2013) Seed bank modelling of volunteer oil seed rape: from seeds fate in the soil to seedling emergence. Planta Daninha. 31: 267-279.
26 . Soltani E and Farzaneh S (2014) Hydrotime analysis for determination of seed vigour in cotton. Seed Science and Technology. 42(2): 260-273.
27 . Thygerson T, Harris JM, Smith BN, Hansen LD, Pendleton RL and Booth DT (2002) Metabolic response to temperature for six populations of winterfat (Eurotia lanata). Thermochimica Acta. 394: 211-217.
28 . Windauer LB, Altuna A and Benech-Arnold RL (2007) Hydrotime analysis of Lesquerella fendleri seed germination responses to priming treatments. Industrial Crops and Products. 25(1): 70-74.