اثر اوره و نیکل بر رشد، غلظت نیترات و عناصر معدنی کاهو رقم سیاهو در آبکشت

نوع مقاله : مقالات پژوهشی

نویسندگان

دانشگاه شاهد

چکیده

کودهای نیتراتی معمول ترین منابع نیتروژن مورد استفاده در کشت های هیدروپونیک هستند که این کودها سبب تجمع نیترات در سبزی های برگی می شوند. بنابراین، تامین نیتروژن گیاه از منبع اوره همراه با نیکل به عنوان کوفاکتور آنزیم اوره آز می تواند نقش مهمی را در کاهش تجمع نیترات در گیاهان ایفا کند. برای این منظور آزمایشی به صورت فاکتوریل در قالب طرح کاملا تصادفی با پنج سطح اوره (0، 25، 50، 75 و 100 میلی‌گرم بر لیتر) و دو سطح نیکل (0 و 2 میلی‌گرم بر لیتر) از منبع NiSO4 در چهار تکرار در شرایط آبکشت (Floating) در کاهوی رقم سیاهو (Lactuca sativa cv. Siyahoo)، اجرا شد. نتایج آزمایش نشان داد که، اثر غلظت های مختلف اوره، کاربرد نیکل و اثرات متقابل آن ها بر وزن تر و خشک اندام های هوایی گیاه معنی دار بود. بیشترین وزن تر و خشک در تیمار U50Ni0 بدست آمد. غلظت نیکل و پتاسیم بافت برگ توسط اوره، نیکل و اثرات متقابل آن ها بطور معنی داری (01/0P≤) تحت تاثیر قرار گرفت. غلظت نیتروژن کل برگ با افزایش غلظت اوره بطور معنی داری (01/0P≤) افزایش یافت؛ در اثرات متقابل نیز بیشترین و کمترین غلظت نیتروژن کل با 5/1 برابر اختلاف بترتیب در تیمارهای U0Ni2 و U0Ni0 بدست آمد. غلظت های مختلف اوره اثر معنی‌داری بر غلظت نیترات بافت برگ نداشتند ولی کاربرد نیکل و اثرات متقابل اوره و نیکل غلظت نیترات بافت برگ را به طور معنی داری (01/0P≤) کاهش داده بود بطوری‌که در تیمار U0Ni2 6/2 برابر کمتر از تیمار U0Ni0 نیترات ثبت شد. به نظر می رسد کاربرد نیکل بتواند نیترات برگ را کاهش دهد.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of Ni and Urea on Growth, Nitrate and Nutrients Concentration in Lettuce (Lactuca sativa) Grown in Hydroponics

نویسندگان [English]

  • Hosein Nazari Mamaqani
  • Seyed Jalal Tabatabaei
Shahed University
چکیده [English]

Introduction: The N source used in commercial hydroponic culture of vegetables is mainly NO3-N. The rate of NO3- uptake is usually high, particularly in leafy vegetables and it can be markedly increased when the NO3- supply in the environment is high. An abundant N supply leads to a high NO3-N absorption and accumulation in plants. When NO3- rich vegetables are consumed, various harmful effects on human health may occur such as met-hemoglobinemia (Blue Baby Syndrome) and cancer. Keeping levels of NO3- below limits of FAO seems to be impossible without changing conventional fertilizer application techniques. The suitability of urea for the cultivation of field crops has been well documented. Urea is used as the main source of N fertilizer for crops grown in soil. Its use as N source for crops grown under the hydroponic system has yet to be evaluated. To hydrolyze urea, the enzyme urease requires Ni as a component. Substitution of urea for commonly used N03-N fertilizers in hydroponic culture of vegetables would not only enable to avoid excessive accumulation of N03- in plants but would also reduce the cost of production. Leafy vegetable crops, such as lettuce and spinach, contain large amounts of N03-N. Therefore, it is important to reduce N03- concentrations in hydroponically grown with lowest negative effects on yield.

Materials and Methods: The experiments were carried outin greenhouse hydroponicsResearchFaculty of Agriculture, University of Tabriz in randomized complete block designwithtwo factors ureaatfivelevels of 0,25, 50, 75and100milligrams perliter(U0, U25,U50, U75, U100)andnickelattwo levels of0and2mg per liter (Ni0, Ni2)ofnickelsulfate(NiSO4)in4replicatesusinglettuce(Lactuca sativa cv. Siyahoo). Plants fed with the modifiedHoagland solutionorhalf theconcentration. Treatments added to nutrient solution when plants were in four leaf stage. Plants were harvested 50 days after treatment. Different organs (leaves, stems and roots) were separated and each separate simultaneous freshweight wasmeasured. Dry weight of organs wasmeasured afterit was oven-dried at 80ºCfor 72h. Leavesoven-dried andthenpowdered, and weredigested(usingacid) tomeasure theelements. Extracts from thedigestionmethodwere used for determination ofnickelusingDimethylglyoximemethod.Spectrophotometer used to cover the wavelength at 530nm. Potassium was measured by Flame Photometer410.Totalnitrogenwas measuredbyKjeldahlmethod.Thehomogeneouspowders of dried leaves with hot water were extractedwithnitratemeter(Horiba, Japan)and they were used to measuretheirnitrate content. Analysis was performed usingthe Software Statistical Package for the Social Science (SPSS) v. 16.0. Individual treatment means were compared with a Duncan’s test to determine whether they were significantly different at the 0.05 probability.

Results and Discussion: U50treatedwith 1.8 fold increasecompared with thecontrol groupshowed thehighestfresh weight. The yield increased with increasing concentration to 50 mg/l urea, butat higher urea concentrations, 50 mg/l,yieldsignificantlydecreased, althoughitwas significantlyhighercompared to control. .Enhanced growth and yield in two levels of U25 and U50were coerced. It was duo tohydrolysis urea with the help nickel stored in seed endosperm and also contamination application of nickel fertilizers in nutrient solutionsthat led to release of urea nitrogen.The highestandthelowest concentration ofnickelinleaveswith11-fold increase,were observedatconcentrations ofU50andU100, respectively. Dilution phenomenon occurred with increasingurea concentrationmore than U50.Nickelconcentration inleaveswassignificantlyincreased that this is theopposite offresh weightanddry weight. In U50 treated K concentration was 1.6-fold higher compared to control. With increasing urea concentration more than U50,K concentration decreased. Applyingthe Ni, 8 percent decreased K concentration in leaf tissues. With increasing urea innutrientsolution, totalnitrogenconcentration of leaf tissuealsoincreased,so that theplantsU100 have 1/1-foldmoretotalnitrogencomparedwithU25plants. Theinteractions betweenthe treated also showed that plantsU0Ni2compared to control(U0Ni0), have 1.2-fold moretotalnitrogen. Concentration ofnitrateinplantsleavesthat showednickelwas 1.2 fold highercompared to the plants withoutnickel.Interactive effectofureaconcentration andapplication ofnickelalso showedthat treated plants hadU0Ni0 2.6-fold more nitratethanU0Ni2plantsleaftissues.
Conclusion: Urea was hydrolyzed in low and middle concentrations (U25 and U50) and led to increasing yield. An inhibition of NO3- uptake can result from the action of Ni on H+- ATPase pump, though it can also affect the carrier of H+/NO3symport. Moreover, proteins of the NO3- uptake system contain -SH groups, and due to that they are sensitive to heavy metals including Ni.

کلیدواژه‌ها [English]

  • Hydroponics
  • Leafy vegetables
  • Nitrate accumulation
  • Nitrogen
  • Potassium
- Alam M.M., Hayat S., Ali B., and Ahmad A. 2007. Effect of 28- homobrassinolide treatment on nickel toxicity in Brassica juncea. Journal of Photosynthetica, 45:139-142.
- Aminuddin H., Khalip R., Norayah K., and Alas H. 1993. Urea as the Nitrogen Source in NIT Hydroponic System. PertanikaJ. Trap. Agricultural Science, 16(2):87-94.
- Anke M., Losch E., Muller M., Groppel B; and Hubschman J. 1991. Nickel supply and nickel load of man in central Europe. Mengen und Spurenelemente, 11, Arbeitstangung, Leipzig, 12-13 Dec., pp. 609-626. Germany.
- Anonymous. 2001. Codex Alimentarius Commission (FAO/WHO). Food additives and contaminants-Joint FAO/WHO Food Standards Programme. 2001, ALINORM 01/12A, pp. 1-289.
- Barker A.V., and Maynard D. 1972. Cation and nitrate accumulation in pea and cucumber plants as influenced by nitrogen nutrition. Journal of the American Society for Horticultural Science, 97,1:27-30.
- Bybordi A., and Gheibi M.N. 2009. Growth and Chlorophyll Content of Canola Plants Supplied with Urea and Ammonium Nitrate in Response to Various Nickel Levels. Notulae Scientia Biologicae, 1(1),53-58.
- Cao H., Ge Y., Liu D., Cao Q., Chang S.X., Chang J., Song X., and Lin X. 2011. Nitrate/Ammonium ratios affect ryegrass growth and nitrogen accumulation in a hydroponic system. Journal of Plant Nutrition, 34:206–216.
- Cataldo D.A., Garland T.R., and Wildung R.E. 1978. Nickel in plants I. Uptake kinetics using intact soybean seedlings. Plant Physiology Biochemistry, 62:563-565.
- Chaillou S., Morot-Gaudry J.F., Salsac L., Lesaint C., and Jolivet E. 1986. Compared effects of NO3– or NH4+ on growth and metabolism of French bean. Physiologie Vegetal, 24:679–687.
- Chen B.M., Wang Z.H., Li S.X., Wang G.X., Song H.X., and Wang X.N. 2004. Effects of nitrate supply on plant growth, nitrate accumulation, metabolic nitrate concentration and nitrate reductase activity in three leafy vegetables. Plant Science, 167:635- 643.
- Chen C., Huang D., and Liu J. 2009. Functions and toxicity of nickel in plants: recent advances and future prospects. Clean- Soil, Air, Water, 37:304-313.
- Dixon N.E., Hinds J.A., Fihelly A.K., Gozala C., Winzor D.J., Blakeley R.L., and Zerner B. 1980. Jack bean urease (EC 3.5.1.5). IV. The molecular size and mechanism of inhibition by hydroxamic acids. Spectrophotometric fixation of enzymes with reversible inhibitors. Canadian Journal Biochemistry, 58:1323-1334.
- Fabrice H., Maria G., and Jose Maria G.M. 2007. Nitrogen fertilizer source effects on the growth and mineral nutrition of pepper (Capsicum annuum L.) and wheat (Triticum aestivum L.). Journal of the Science Food and Agricultures, 87:2099-2105.
- Hoseini F., Khoshgoftarmanesh A.H., and Afyuni M. 2012. Influence of nickel nutrition and nitrogen source on growth and yield of lettuce in hydroponic culture. Journal of Science and Technology Greenhouse Culture, 3 (9):53-62. (in Persian)
- Khan K.N., Watanabe M., and Watanabe Y. 1999. Effect of Different Concentrations of Urea with or without Nickel Addition on Spinach (Spinacia oleracea L.) Growth under Hydroponic Culture. Soil Science and Plant Nutrition, 45(3),569-575.
- Marschner H. 2002. Mineral nutrition of higher plants, 3rd ed. Academic Press, London, pp 364-369.
- McClure P.R., Kochian L.V., Spanswick R.M., and Shaff J.E. 1990. Evidence for cotransport of nitrate and protons in maize roots. I. Effect of nitrate on the membrane potential. Plant Physiology, 93:281–289.
- Mensinga T.T., Speijers G.J.A., and Meulenbelt J. 2003. Health implications of exposure to environmental nitrogenous compounds. Toxicological Reviews, 22:41-51.
- Morrison R., Brooks R., and Reeves R. 1980. Nickel uptake by Allysum species. Plant Science Letters, 17:451-460.
- Panda, N., and Sharma C.P. 2002. Effect of heavy metals CO2+, Ni2+, and Cd2+ on growth and metabolism of cabbage. Plant Science, 163:753-758.
- Seregin I.V., and Kozhevnikova A.D. 2006. Physiological role of nickel and its toxic effects on higher plants. Russian Journal of Plant Physiology, 53:257-277.
- Sykula-Zajac A., Turek M., Mathew M.P., Patai F., Horvat M., and Jablonska J. 2010. Determination of Nickel in Tea by Using Dimethylglyoxime Method. Food Chemistry and Biotechnology, Vol. 74:1-11.
- Tabatabaei S.J. 2013. Principles of Mineral Nutrition of Plants. University of Tabriz. Iran. (in Persian)
- Tan X.W., Ikeda H., and Oda, M. 2000. Effect of nickel concentration in the nutrient solution on the nitrogen assimilation and growth of tomato seedling in hydroponic culture supplied with urea or nitrate as the sole nitrogen source. Scientia Horticulturae, 84:265-273.
- Watanabe Y., and Shimada N. 1990. Effect of nickel on the plant growth and urea assimilation in higher plants. Trans. 14th Intl. Congress of Soil Sciences, August 1990, 4: 146-151. Kyoto, Japan.
- Yusuf M., fariduddin Q., Hayat S., and Ahmad A. 2011. Nickel: An Overview of Uptake, Essentiality and Toxicity in Plants. Bull Environ Contam Toxicol, 86:1–17.