Microscopic Investigation of Cold Plasma Effect on Chickpea Seed Germination

Document Type : Research Article

Authors

• M. Fereydoni
• H. Haji Agha Alizaheh

Department of Biosystem, Faculty of Agriculture, BuAli Sina University, Hamedan, Iran

https://doi.org/10.22067/jam.v12i2.88718

Abstract

Introduction
As the world's population grows, more food need to be produced. Plasma technology is one of the methods that can improve plant growth. Cold plasma is effective in increasing growth and germination indices. In this article, the effect of cold plasma based on corona discharge was investigated on germination of Adel, Mansur, and Azad chickpea varieties.
Materials and Methods
In the corona discharge method, a relative vacuum should be used. Corona discharge is formed when there are pronounced spatial in-homogeneities in the electric field, in particular, when the electric field exceeds the breakdown threshold in a limited spatial region. This commonly occurs when highly asymmetric electrodes are employed, such as a point and a plane. Thermodynamically corona is a very non-equilibrium process, creating a non-thermal plasma. The avalanche mechanism does not release enough energy to heat the gas in the corona region generally and ionize it, as occurs in an electric arc or spark. Only a small number of gas molecules take part in the electron avalanches and are ionized, having energies close to the ionization energy of 1- 3 ev, the rest of the surrounding gas is close to ambient temperature. Corona discharge is a weakly ionized non-equilibrium plasma based on the avalanche mechanism. If it reaches a close distance with a conductive material or increase the electrical field, it can create longer breakdown streamers and eventually create sparks. The system is designed to convert 220V voltage with a frequency of 50 Hz to 12 kV voltage with a frequency of 9 kHz. Two electrodes with a 2 cm distance are in a vacuum chamber with a negative pressure of 20 pounds per square inch. And the samples are placed between two electrodes. Experiment was performed in form of a.factorial experimental design based on a CRD. In this plan, treatments are randomly placed in experimental units. The type of factorial experiment performed is 3×3×2×2 and multiplied numbers are factor levels. Seed production year factor in two levels, moisture factor in two levels, Seed variety factor in three levels, and exposure duration factor in three levels were examined. Plasma-exposed seeds and non-exposed seeds were grown under the same conditions. The samples were selected completely randomly. The samples were wetted 24 hours before exposure. Then all 18 chickpeas were placed in a dish in order to observe proper repetition. Samples from each dish were exposed to cold plasma under the same conditions between samples for a specified period of time. After exposing the samples to cold plasma, samples of all dishes under the same conditions at 30 °C and 300 lux environmental light were examined for germination evaluation. For this purpose, samples of each dish were placed in a cover of cotton cloth. They got wet every 4 hours. After 48 hours, all samples were examined and the root length of each sample was measured.
Results and Discussion
The results showed that seeds exposed to plasma for 60 seconds had a faster germination speed than those without exposure. Also, seeds that were exposed to plasma for 30 seconds had a longer root length than those without exposure. According to the results of statistical analysis, exposure to cold plasma for 30 seconds has increased root length in Adel chickpea variety up to 12.5% and in Mansour variety up to 18%.
Conclusion
After statistical analysis, appear that root length under the same conditions, during 30 seconds of exposure to cold plasma, is significant at 5% level from non-exposure and 60 seconds of exposure. Microscopic images of samples were examined on the outer surface and inner tissue of seed cell. Studies have shown that the outer surfaces of seeds exposed to cold plasma are smoother, less prominent and smaller contact angle than those without exposure to plasma. This change can increase the hydrophilicity of seeds. But cold plasma had no effect on cell tissue in terms of size and number.

Keywords

• Cold plasma
• Microscopic image
• Chickpea
• Germination

20.1001.1.22286829.1401.12.2.11.3

Open Access

©2020 The author(s). This article is licensed under Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source.

References

1. Amnuaysin, N., H. Korakotchakorn, S. Chittapun, and N. Poolyarat. 2018. Seed germination and seedling growth of rice dielectric barrier discharge plasma. Songklanakarin Journal of Science & Technology 40: 819-823.
2. Bakhshy, E., F. Zarinkamar, and M. Nazzari. 2020. Structural and quantitative changes of starch in seed of Trigonella persica during germination. International Journal of Biological Macromolecules 164: 1284-1293.
3. Banaschik, R., G. Burchhardt, K. Zocher, S. Hammerschmidt, J. F. Kolb, and K. Weltmann. 2016. Comparison of pulsed corona plasma and pulsed electric fields for the decontamination of water containing Legionella pneumophila as model organism. Bioelectrochemistry 112: 83-90.
4. Butscher, D., H. Van Loon, A. Waskow, P. Rudolf von Rohr, and M. Schuppler. 2016. Plasma inactivation of microorganisms on sprout seeds in a dielectric barrier discharge. International Journal of Food Microbiology 238: 222-232.
5. Jian, F., K. Sun, V. Chelladurai, D. S. Jayas, and N. White. 2014. Quality changes in high and low oil content canola during storage: Part II – Mathematical models to predict germination. Journal of Stored Products Research 59: 328-37.
6. Khamsen, N., A. Akkarachanchainon, K. Fookiat, J. Srisala, S. Chomchuen, W. Kanokbannakorn, and S. Srisonphan. 2016a. Atmospheric Cold Plasma via Fringe Field Enhanced Corona Discharge on Single Dielectric Barrier for Large-volume Applications. Procedia Computer Science 86: 321-24.
7. Khamsen, N., A. Akkarachanchainon, N. Teerakawanich, and S. Srisonphan. 2016b. Organic and Bio Material Surface Modification Via Corona Discharge Induced Atmospheric-cold Plasma. Procedia Computer Science 86: 325-28.
8. Kim, J., P. Puligundla, and Ch. Mok. 2015. Microbial decontamination of dried laver using corona discharge plasma jet (CDPJ). Journal of Food Engineering 161: 24-32.
9. Kuwahara, T., T. Kuroki, K. Yoshida, N. Saeki, and M. Okubo. 2012. Development of sterilization device using air nonthermal plasma jet induced by atmospheric pressure corona discharge. Thin Solid Films 523: 2-5.
10. LoPorto, Ch., L. Sergio, F. Boari, A. F. Logrieco, and V. Cantore. 2019. Cold plasma pretreatment improves the germination of wild asparagus (Asparagus acutifolius) seeds. Scientia Horticulturae 256: 108554.
11. Misra, N. N., O. K. Schluter, and P. J. Cullen. 2016. Cold plasma in food and agriculture. Elsevier Inc.
12. Mohsenin, N. N. 1986. Physical properties of plant and animal materials.
13. Perez, P., M. Cecilia, L. Prevosto, C. Zilli, E. Cejas, H. Kelly, and K. Balestrasse. 2018. Effects of non-thermal plasmas on seed-borne Diaporthe/Phomopsis complex and germination parameters of soybean seeds. Innovative Food Science & Emerging Technologies 49: 82-91.
14. Raizer, Y. 2011. Gas discharge physics. Springer. New York.
15. Rawlins, J. K., B. A. Roundy, D. Egget, and N. Cline. 2012. Predicting germination in semi-arid wildland seedbeds II. Field validation of wet thermal-time models. Environmental and Experimental Botany 76: 68-73.
16. Shapira, Y., E. Bormashenko, and E. Drori. 2019. Pre-germination plasma treatment of seeds does not alter cotyledon DNA structure, nor phenotype and phenology of tomato and pepper plants. Biochemical and Biophysical Research Communications 1: 100259.
17. Shashikanthalu, S. P., L. Ramireddy, and M. Radhakrishnan. 2020. Stimulation of the germination and seedling growth of Cuminum Cyminum seeds by cold plasma. Journal of Applied Research on Medicinal and Aromatic Plants 519: 512-517.
18. Takahashi, K., Y. Saito, R. Oikawa, T. Okumura, K. Takaki, and T. Fujio. 2018. Development of automatically controlled corona plasma system for inactivation of pathogen in hydroponic cultivation medium of tomato. Journal of Electrostatics 91: 61-69.
19. Wu, T., N. Sun, and Ch. Chau. 2018. Application of corona electrical discharge plasma on modifying the physicochemical properties of banana starch indigenous to Taiwan. Journal of Food and Drug Analysis 26: 244-51.
20. Xinyu, L., Z. Song, W. Xu, Y. Li, Ch. Ding, and H. Chen. 2020. Spectral characteristics on increasing hydrophilicity of alfalfa seeds treated with alternating current corona discharge field. Biomolecular Spectroscopy. 236: 118350.
21. Yodpitak, S., S. Mahatheeranont, D. Boonyawan, Ph. Sookwong, S. Roytrakul, and O. Norkaew. 2019. Cold plasma treatment to improve germination and enhance the bioactive phytochemical content of germinated brown rice. Food Chemistry 289: 328-39.
22. Zarei, S., M. Kasraei, and M. A. Nematollahi. 2020. Investigating the impact of the magnetized water on the growth and germination of five wheat grain seeds. Journal of Agricultural Machinery 10 (2): 289-298. (In Persian). http://dx.doi.org/10.22067/jam.v10i2.76707.