Stratospheric conditions on germination and seedlings of Solanum and Beta 45 ISSN Versión impresa: 1992-2159; ISSN Versión electrónica: 2519-6412 Biotempo, 2024, 21(1), jan-jun.: 45-52. ORIGINAL ARTICLE / ARTÍCULO ORIGINAL EFFECT OF STRATOSPHERIC CONDITIONS ON GERMINATION AND SEEDLINGS OF SOLANUM LYCOPERSICUM “TOMATO PRINCE BORGHESE” AND BETA VULGARIS “BEET”EFECTO DE LAS CONDICIONES ESTRATOSFÉRICAS EN LA GERMINACIÓN Y PLÁNTULAS DE SOLANUM LYCOPERSICUM “TOMATE PRINCIPE BORGHESE” Y BETA VULGARIS “BETARRAGA” Diego Adolfo Dueñas-Parapar 1,5* ; Alvaro Ezequiel Ostolaza-Saz 3 ; Maria Alejandra Garcia-Orosco 1 ; Octavio A. Chon-Torres 4 ; Hugo Duglas Aquiles González-Figueroa 1,2 Biotempo (Lima) doi:10.31381/biotempo.v21i1.6409 https://revistas.urp.edu.pe/index.php/Biotempo Este artículo es publicado por la revista Biotempo de la Facultad de Ciencias Biológicas, Universidad Ricardo Palma, Lima, Perú. Este es un artículo de acceso abierto, distribuido bajo los términos de la licencia Creative Commons Atribución 4.0 Internacional (CC BY 4.0) [https:// creativecommons.org/licenses/by/4.0/deed.es] que permite el uso, distribución y reproducción en cualquier medio, siempre que la obra original sea debidamente citada de su fuente original. RevistaBiotempo Volumen 21 (1) Enero-Junio 2024 ISSN Versión Impresa: 1992-2159; ISSN Versión Electrónica: 2519-5697 Facultad de Ciencias Biológicas de laUniversidad Ricardo Palma (FCB-URP) ABSTRACT T e stratosphere is a layer of the Earth’s atmosphere, located above the anthroposphere and below the mesosphere. T e stratosphere has particular meteorological conditions, such as high UV-A radiation, slow atmospheric pressure, and temperature variations. Currently, several studies have shown that organisms such as plants can be positively af ected by exposure to stratospheric conditions, especially UV-A radiation. However, studies on the viability of seeds have been little developed. For this reason, this study aimed to evaluate the viability of Solanum lycopersicum Lam, 1794 “Tomato Prince Borghese” and Beta vulgaris Linneo, 1753 “Beet” seeds under stratospheric conditions. T e seeds were taken to the stratosphere by the stratospheric balloon of the “Asociación Peruana de Astrobiología”, which is also equipped with meteorological instruments to measure the altitude, temperature, atmospheric pressure, and UV-A radiation present from launch to the return of the sample. Seed viability has been determined based on a comparative analysis of germination and early stem and root elongation of seeds exposed to stratospheric and unexposed conditions. T e main results show that stratospheric conditions increase signif cantly stem elongation in S. lycopersicum and total weight in both species. T is research presents interesting results for the study of techniques for the rapid germination and development of crops. Keywords : Beta vulgaris – germination – seedlings – Solanum lycopersicum – stratosphere – UV-A 1 Biological Sciences Faculty, Ricardo Palma University, Lima, Perú. 2 Molecular Biotechnology Laboratory, Biological Sciences Faculty, Ricardo Palma University, Lima, Perú. 3 Zoology Laboratory, Biological Sciences Faculty, Ricardo Palma University, Lima, Perú. 4 General Studies Program, University of Lima, Lima, Perú. 5 South America – SGAC, Space Generation Advisory Council, Vienna, Austria.* Corresponding author: diego.duenas@spacegeneration.orgDiego Dueñas-Parapar: https://orcid.org/0000-0003-1040-647XAlvaro Ostolaza-Saz: https://orcid.org/0000-0002-6965-231XMaria Garcia-Orosco: https://orcid.org/0000-0002-0625-5405Octavio A. Chon-Torres: https://orcid.org/0000-0003-3905-6784Hugo Gonzales-Figueroa: https://orcid.org/0000-0003-0760-8812
Revista Biotempo: ISSN Versión Impresa: 1992-2159; ISSN Versión electrónica: 2519-5697Dueñas-Parapar et al. 46 RESUMEN La estratosfera es una capa de la atmósfera terrestre, situada por encima de la antroposfera y por debajo de la mesosfera. La estratosfera presenta condiciones meteorológicas particulares, como una elevada radiación UV-A, y variaciones lentas de la presión atmosférica y la temperatura. En la actualidad, varios estudios han demostrado que organismos como las plantas pueden verse afectados positivamente por la exposición a las condiciones estratosféricas, especialmente a la radiación UV-A. Sin embargo, los estudios sobre la viabilidad de las semillas han sido poco desarrollados. Por esta razón, el objetivo de este estudio fue evaluar la viabilidad de las semillas de Solanum lycopersicum Lam, 1794 “Tomate Príncipe Borghese” y Beta vulgaris Linneo, 1753 “Remolacha” en condiciones estratosféricas. Las semillas fueron llevadas a la estratósfera por el globo estratosférico de la “Asociación Peruana de Astrobiología”, que además está equipado con instrumentos meteorológicos para medir la altitud, temperatura, presión atmosférica y radiación UV-A presentes desde el lanzamiento hasta el retorno de la muestra. La viabilidad de las semillas se ha determinado a partir del análisis comparativo de la germinación y el alargamiento temprano de tallos y raíces de semillas expuestas a condiciones estratosféricas y no expuestas. Los resultados principales de esta investigación demuestran que las condiciones estratosféricas aumentan signifcativamente la elongación del tallo en S. lycopersicum y el peso en ambas especies. Esta investigación presenta resultados interesantes para el estudio de técnicas de germinación rápida y desarrollo de cultivos. Palabras clave : Beta vulgaris – estratosfera – germinación – plántulas – Solanum lycopersicum – UV-A INTRODUCTION Agriculture is one of the oldest and most necessary human activities for civilization, since it provides fresh food with high content of vitamins and minerals that are useful for the organism (Flannery, 1973; Merrill, 1983). Over time, cultivation techniques have been perfected until the inclusion of new variables that can favor and increase the production of plants and fruits (Tudi et al ., 2021; Liu et al ., 2022).Nowadays, seed germination is a biological process that has been widely studied since it will determine the adaptation of the species to environmental conditions (Klupczyńska & Pawłowski, 2021). Several authors have studied the diferent factors afecting germination and growth of crop plants (Kim & Kim, 2019; Al-Quraan et al ., 2020; Altuner, 2020; He et al ., 2020). Also, pretreatments using UV-A radiation have been demonstrated to increase the germination rate, foliar area, dry mass, root and stem of plants (Hamid & Jawaid, 2011; Mariz-Ponte et al. , 2018).Beet and tomato are food products that present a wide range of vitamins and minerals that complement the human diet (Ordóñez-Santos et al., 2011; Cliford et al ., 2015). In addition, they are vegetables that can be cultivated worldwide, so studying techniques for the increase and improvement of their production is very important (Ceclu & Nistor, 2020; Collins et al ., 2022).In this study, we have sent two species of seeds, Solanum lycopersicum Lam, 1794 “Tomato Prince Borghese’’ and Beta vulgaris Linneo, 1753 “Beet”, to the stratosphere, exposing them to extreme environmental conditions such as increased UV-A radiation, temperature and atmospheric pressure variations; these variables are important for the viability of the future plant. Te experiment was carried out using a meteorological balloon and the viability indicators to determine were germination success and early growth of the stem and roots. MATERIALS AND METHODS Seed obtaining Te seeds were acquired from the company ANASAC, which is a Chilean company dedicated to the agriculture feld (Anasac, 2024). Seed packs indicate that they have a purity of 99.90%. Seed exposition to Stratosphere Te exposition of seeds to stratospheric conditions was carried out by the meteorological balloon launched by the “Asociación Peruana de Astrobiología” on February 12, 2022 in Yauca, province of Ica, Peru. Te balloon reached about an altitude of 30 000 km above sea level. Once reached that altitude, the balloon exploded and dropped the seed sample
Stratospheric conditions on germination and seedlings of Solanum and Beta 47 and the climatological measurement equipment with a parachute to slow the speed of impact with the ground. Te meteorological measurements were made using the Strato4 instrument, which recorded temperature, altitude, humidity and UV-A radiation throughout the fight. Strato4 is a weather measurement system manufactured by the Stratofights company in Germany (Stratofights, 2024). Seed cultivation Once the sample was returned, the tomato and beet seeds were placed in a plastic multi-well seedbed at the same time as the control seeds, totaling 72 seeds. Te sample size per group was 18, which was close to reported by Noble (2002). Te seeds were grown using cotton as an absorbent substrate. Te use of cotton is justifed in this experiment due to its liquid retaining capacity and also to its moldable structure that allows us to monitor the development of the seeds. Irrigation per sample was 5 mL of water per 24 hours. Tis quantity of water was chosen because it maintained a humid environment for the samples, which is favorable for seed germination (Kauth & Biber, 2015, Jung et al ., 2020). Germination and stem and root development Te germination time of each seed was recorded using days as the unit of measurement. Once the post-germination cycle started, the stems and roots were recorded every 3 days using centimeters as the unit of measurement.On day 20, all evaluated individuals were transported to the Botany Laboratory of the Biological Sciences Faculty – Universidad Ricardo Palma, Lima, Perú for transplanting to a sandy substrate. Before transplanting, the weight, stem length and main root length of each individual were recorded. Statistics and generation of graphs Boxplots and confdence intervals were determined using R Studio software. Statistical analysis was performed by using unpaired t-tests to determine similarities or diferences in the radiation-exposed and control groups. T tests were calculated by species for each of the variables. ETHIC ASPECTS Tis study has been carried out with the strictest respect for ethical principles, with the aim of making a responsible contribution to scientifc knowledge and to the welfare of society. RESULTS Meteorological conditions Te StratoTrack4 weather measurement system shows that the maximum altitude obtained in this experiment was 28 224.5 km above sea level. In addition, it indicates that during the experiment there were temperature changes that ranged from -66.00°C to 31.90°C, giving an average of -25.02°C. Regarding humidity, extreme data of 0.10% and 99.26% were obtained, with 39.68% as arithmetic mean. Te UV-A radiation has presented abrupt changes throughout the experiment, with an index between 0.32 (low) and 9.09 (very high), being 3.39 (moderate) the mean (Figure 1). Figure 1 . Meteorological conditions from the launch to the return of the sample.
Revista Biotempo: ISSN Versión Impresa: 1992-2159; ISSN Versión electrónica: 2519-5697Dueñas-Parapar et al. 48 Germination For the S. lycopersicum group exposed to the stratosphere, germination began on day 3, with 15 germinations (83.33%) until day 5 and all of them on day 7. In the control group, germination began on day 3, with 16 seeds germinating (88.89%) by day 5 and all on day 6. T student value was 0.6014 and the p -value was 0.5516, therefore this result is not statistically signifcant. For the group of B. vulgaris exposed to the stratosphere, the germination of the group started on the second day, having 15 germinations (83.33%) until day 5 and 17 seeds germinated until day 8. In the control group, germination started on the second day, having 15 (83.33%) germinations up to day 5 and 17 germinations until day 11. It is interesting to note that both groups did not show germination in one of their individuals. (Figure 2). T student value was 0.0 and the p -value was 1, therefore this result is not statistically signifcant. Figure 2 . Seed germination of tomato and beet samples. Figure 3 . Total weight of tomato and beet samples. Total weight For the group of S. lycopersicum exposed to the stratosphere, the total weight of the shoots ranges from 0.01 g to 0.15 g, obtaining a mean of 0.078. For the control group, the total weight of the shoots ranges from 0.02 g to 0.2 g, having a mean of 0.11 g (Figure 3). T student value was 2.2081 and the p -value was 0.0341, therefore this result is considered to be statistically signifcant.Te group of B. vulgaris exposed to stratospheric conditions presents a weight between 0.00 gr and 0.17 g, with a mean of 0.08 g. For the control group, the minimum and maximum weights obtained were 0.02 g and 0.25 g, with a mean of 0.13 g (Figure 3). T student value was 2.8018 and the p -value was 0.0086, therefore this result is considered to be statistically signifcant.
Stratospheric conditions on germination and seedlings of Solanum and Beta 49 Stem elongation For the Tomato Prince Borghese seeds exposed to stratospheric conditions, elongations between 2 cm and 4.2 cm were recorded, with 3.38 cm as the mean. For the control group, elongations between 1.3 cm and 3.6 cm were obtained, the mean being 2.67 cm. T student value was 3.4168 and the p -value was 0.0017, therefore this result is statistically signifcant.Te beets developed two stems for each seed, therefore an average of stems was taken, obtaining an average per individual. Te group that had been exposed to stratospheric conditions obtained elongations ranging from 0.7 cm to 4.4 cm, with 2.29 cm as the mean. Te control group obtained elongations between 1.1 cm and 2.4 cm, being 1.875 cm the mean (Figure 4). T student value was 1.7746 and the p -value was 0.0855, therefore this result is considered to be not quite statistically signifcant. Figure 4 : Stem elongation of tomato and beet samples. Main root elongation For S. lycopersicum , the group exposed to the stratosphere obtained main root elongations between 0.6 cm and 12.5 cm, with 5.85 cm as the mean. Te control group obtained results between 2.3 cm and 16.1 cm, with 7.37 cm as the mean. T student value was 1.1309 and the p -value was 0.2660, so this result is considered to be not statistically signifcant. Beta vulgaris generated two principal roots for each seed, therefore, an average of the number of that was recorded, obtaining only one data per individual. Beet seeds exposed to stratospheric conditions showed an elongation between 0.95 cm and 11.3 cm, being 3.39 the mean. Te control seeds showed an elongation between 0.7 cm and 4.4 cm, being 1.99 cm the mean (Figure 5). T student value was 0.5580 and the p -value was 0.5807, so this result is considered to be not statistically signifcant. Figure 5 . Principal root elongation of tomato and beet samples.
Revista Biotempo: ISSN Versión Impresa: 1992-2159; ISSN Versión electrónica: 2519-5697Dueñas-Parapar et al. 50 DISCUSSION Tis study shows that the germination and elongation of stem and main root of S. lycopersicum and B. vulgaris didn’t show signifcant changes when exposed to stratospheric conditions during a meteorological balloon fight. However, stem elongation in S. lycopersicum and total weight in both species showed signifcant diferences. In the study by Fong et al. (2015), three types of seeds were exposed to stratospheric radiation using a meteorological balloon; demonstrating a negative efect on germination success but slight improvement in seedling growth of bean seeds and increased germination success as well as varied responses in seedling development of radish and maize seeds. Te diference in responses to stratospheric conditions may be due to the facility of the species to adapt to unusual environmental conditions.Several studies show that plants modify their metabolism in response to environmental conditions, optimizing their vital performance depending on them, which could accelerate or delay biomass production (Bernal et al ., 2015; Verdaguer et al ., 2017). UV-A radiation is a factor that favors plant development due to the high charge of its photons, which facilitates accelerated photosynthesis and greater energy production. However, prolonged exposure to radiation negatively interferes with the development of the other stages of the plant since it reduces root size and the amount of biomass (Noble, 2002). Studies show that treatments of 8 and 16 hours of UV-A exposure stimulate 29% and 33% plant biomass production, increasing plant length and photosynthetic response (Kang et al ., 2018). Additionally, exposure to UV-A radiation for 1 hour per day in 30 days’ increases fruit production in plants (Mariz-Ponte et al ., 2019).In this research, diferences in stem elongation show that the Tomato Prince Borghese plants (stratosphere group) had a larger size compared to those in the control group. Tis may be due to the diference in the amount of radiation absorbed by UV-A exposure. In addition, this study shows that plants exposed to stratospheric conditions have a lower total weight compared to those in the control group. One of the responses to the diference in shoot weight is the presence of necrosis and dehydration in the roots, which avoids the accumulation of water in the plant and its optimal development. Tis suggests that exposure to stratospheric conditions generates visible changes in plant morphology that are counterproductive in the long term.We concluded that there were no signifcant diferences in the morphology of S. lycopersicum and B. vulgaris exposed to stratospheric conditions during the trajectory of a weather balloon. However, slight diferences in total weight and stem elongation could demonstrate the efect of radiation on plant development. Further studies are needed to determine anomalies in the developmental stages of seeds exposed to stratospheric conditions. ACKNOWLEDGEMENTS Te authors wish to thank Veronica Patricia Parapar Loayza for her helpful support in the life of the corresponding author. Do not let cancer win you, be strong. Author contributions : CRediT (Contributor Roles Taxonomy)DDP = Diego Dueñas-Parapar AOS = Alvaro Ostolaza-Saz MGO = Maria Garcia-Orosco OCT = Octavio Chon-Torres HGF = Hugo Gonzales-Figueroa Conceptualization : DDP Data curation : DDP, AOS, MGO, OCT, HGF Formal Analysis : DDP Funding acquisition : OCT, HGF Investigation : DDP, AOS Methodology : DDP, AOS Project administration : DDP Resources : OCT, HGF Software : DDP Supervision : HGF Validation : OCT, HGF Visualization : DDP, OCT, HGF Writing – original draft : DDP, AOS, MGO Writing – review & editing : DDP, AOS, MGO
Stratospheric conditions on germination and seedlings of Solanum and Beta 51 BIBLIOGRAPHIC REFERENCES Al-Quraan, N. A., Al-Akhras, M. A. H., & Talafha, D. Z. (2020). Te infuence of laser beam and high light intensity on lentil ( Lens culinaris ) and wheat ( Triticum aestivum ) seedlings growth and metabolism. Plant Biosystems , 156 , 95-115.Altuner, F. (2020). Determination of the efect of salt (NaCl) stress on germination of oat ( Avena sativa L.) seeds pretreated with gibberellic acid. Fresenius Environmental Bulletin , 29 , 11111–11118.Anasac (2024). ANASAC. Impulsando un futuro mejor. Anasac. https://anasac.com/es/seeds/ Bernal, M., Verdaguer, D., Badosa, J., Abadía, A., Llusià, J., Peñuelas, J., Nuñez-Olivera, E., & Llorens, L. (2015). Efects of enhanced UV radiation and water availability on performance, biomass production and photoprotective mechanisms of Laurus nobilis seedlings. Environmental and Experimental Botany , 109 , 264-275.Ceclu, L., & Nistor, O. V. (2020). Red beetroot: Composition and health efects—A review. Journal of Nutritional Medicine and Diet Care, 6 , 1-9.Cliford, T., Howatson, G., West, D. J., & Stevenson, E. J. (2015). Te potential benefts of red beetroot supplementation in health and disease. Nutrients , 7 , 2801-2822.Collins, E. J., Bowyer, C., Tsouza, A., & Chopra, M. (2022). Tomatoes: An extensive review of the associated health impacts of tomatoes and factors that can afect their cultivation. Biology , 11 , 239.Flannery, K. V. (1973). Te origins of agriculture. Annual review of Anthropology , 2(1), 271-310.Fong, B. N., Newhouse, K. V., Huss, M. J., Roberts, E., Kennon, J. T., & Ali, H. (2015). Investigating the Efect of Stratospheric Radiation on Seed Germination and Growth. Journal of the Arkansas Academy of Science , 69 , 36-40.Hamid, N., & Jawaid, F. (2011). Infuence of seed pre-treatment by UV-A and UV-C radiation on germination and growth of Mung beans. Pakistan Journal of Chemistry, 1 , 164-167.He, Y. Q., Zhao, J., Feng, D. F., Huang, Z. B., Liang, J. M., Zheng, Y. F., Cheng, J., Jifeng, Y., & Zhoufei, W. (2020). RNA-Seq study reveals AP2-Domain-Containing signalling regulators involved in initial imbibition of seed germination in rice. Rice Science , 27 , 302–314.Jung, E. S., Sivakumar, S., Hong, S. C., Yi, P. I., Jang, S. H., & Suh, J. M. (2020). Infuence of relative humidity on germination and metal accumulation in Vigna radiata exposed to metal-based nanoparticles. Sustainability , 12 , 1347.Kauth, P., & Biber, P. (2015). Moisture content, temperature, and relative humidity infuence seed storage and subsequent survival and germination of Vallisneria americana seeds. Aquatic Botany , 120 , 297-303.Kang, S., Zhang, Y., Zhang, Y., Zou, J., Yang, Q., & Li, T. (2018). Ultraviolet-A radiation stimulates growth of indoor cultivated tomato ( Solanum lycopersicum ) seedlings. HortScience , 53 , 1429-1433.Kim, H. S., & Kim, Y. H. (2019). Infuence of abiotic treatments on isofavone accumulation in soybean seeds during germination. Korean Journal of Crop Science , 64 , 18–24.Klupczyńska, E. A., & Pawłowski, T. A. (2021). Regulation of seed dormancy and germination mechanisms in a changing environment. International journal of molecular sciences , 22 , 1357.Liu, S., Wang, W., Lu, H., Shu, Q., Zhang, Y., & Chen, Q. (2022). New perspectives on physiological, biochemical and bioactive components during germination of edible seeds: A review. Trends in Food Science & Technology , 123 , 187-197.Merrill, M. (1983). Eco-agriculture: a review of its history and philosophy. Biological Agriculture & Horticulture , 1 , 181-210.Mariz-Ponte, N., Mendes, R. J., Sario, S., Melo, P., & Santos, C. (2018). Moderate UV-A supplementation benefts tomato seed and seedling invigoration: a contribution to the use of UV in seed technology. Scientia Horticulturae , 235 , 357-366.Mariz-Ponte, N., Martins, S., Gonçalves, A., Correia, C. M., Ribeiro, C., Dias, M. C., & Santos, C.
Revista Biotempo: ISSN Versión Impresa: 1992-2159; ISSN Versión electrónica: 2519-5697Dueñas-Parapar et al. 52 (2019). Te potential use of the UV-A and UV-B to improve tomato quality and preference for consumers. Scientia Horticulturae , 246 , 777–784.Noble, R. E. (2002). Efects of UV-irradiation on seed germination. Science of the Total Environment , 299 , 173-176.Ordóñez-Santos, L. E., Vázquez-Odériz, M. L., & Romero-Rodríguez, M. A. (2011). Micronutrient contents in organic and conventional tomatoes ( Solanum lycopersicum L.). International Journal of Food Science & Technology , 46 , 1561-1568.Stratofights. (2024). Registrador de dato s STRATO4. Stratofights . https://www.stratofights.com/es/shop/registrador-datos/ Tudi, M., Daniel Ruan, H., Wang, L., Lyu, J., Sadler, R., Connell, D., Chu, C. & Phung, D. T. (2021). Agriculture development, pesticide application and its impact on the environment . International journal of environmental research and public health, 18 , 1112.Verdaguer, D., Jansen, M. A. K., Llorens, L., Morales, L. O., & Neugart, S. (2017). UV-A radiation efects on higher plants: Exploring the known unknown. Plant Science, 255 , 72–81.Received January 8, 2024.Accepted February 29, 2024.