Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress

Temperature and salinity level of the imbibition medium play a crucial role in regulating seed germination and seedling emergence, which is also true in microgreen production, where temperature and water potential may influence seed germination alone and/or in combination. In this study, the effects...

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Main Authors: Stefania Toscano, Daniela Romano, Valeria Cafaro, Cristina Patanè
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Agronomy
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Online Access:https://www.mdpi.com/2073-4395/15/2/361
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author Stefania Toscano
Daniela Romano
Valeria Cafaro
Cristina Patanè
author_facet Stefania Toscano
Daniela Romano
Valeria Cafaro
Cristina Patanè
author_sort Stefania Toscano
collection DOAJ
description Temperature and salinity level of the imbibition medium play a crucial role in regulating seed germination and seedling emergence, which is also true in microgreen production, where temperature and water potential may influence seed germination alone and/or in combination. In this study, the effects of different temperatures and water potentials in NaCl, alone or in combination, upon germination and early radicle growth, were assessed in two species for microgreen production (<i>Eruca sativa</i>-rocket, and <i>Raphanus sativus</i>-radish). Seeds were germinated at eight constant temperatures (from 5 to 35 °C) and five water potentials (<i>ψ</i>) in NaCl (from 0 to −1.2 MPa). Final germination percentage (FGP) was maximized at 15–20 °C in rocket, and at 20–25 °C in radish. As the temperature increased or decreased, germination was reduced and became less uniform, to a greater extent, at suboptimal temperatures in both species. Across water potentials, FGP values exceeding 50% at the highest temperature in radish indicated a greater tolerance than rocket to supraoptimal temperatures during germination. Across temperatures, FGP and germination speed in both species were progressively depressed as the water potential decreased. The adverse effects of NaCl progressively increased as the temperature moved away from its optimal value. Overall, rocket seeds were able to germinate well (>80%) at 20 °C at salinity levels down to −0.9 MPa, while radish seeds were able to germinate well (≥90%) at 25 °C at salinity levels down to −0.9 MPa. Salt stress tolerance was higher in rocket and radish at low and high temperatures, respectively. Both thermal time and hydrotime requirements were higher in radish because its seeds took longer to germinate. Thermal time and hydrotime may help to predict the germination capacity and time, once the temperature or water potential of the imbibition substrate is known. The findings of this study have important implications for the large-scale industrial production of microgreens.
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spelling doaj-art-292833778ded4026b47cfcff0061cf022025-08-20T02:44:36ZengMDPI AGAgronomy2073-43952025-01-0115236110.3390/agronomy15020361Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt StressStefania Toscano0Daniela Romano1Valeria Cafaro2Cristina Patanè3Department of Veterinary Sciences, University of Messina, 98168 Messina, ItalyDepartment of Agriculture, Food and Environment (Di3A), University of Catania, 95131 Catania, ItalyInstitute of BioEconomy (IBE), Italian National Research Council (CNR), 95126 Catania, ItalyInstitute of BioEconomy (IBE), Italian National Research Council (CNR), 95126 Catania, ItalyTemperature and salinity level of the imbibition medium play a crucial role in regulating seed germination and seedling emergence, which is also true in microgreen production, where temperature and water potential may influence seed germination alone and/or in combination. In this study, the effects of different temperatures and water potentials in NaCl, alone or in combination, upon germination and early radicle growth, were assessed in two species for microgreen production (<i>Eruca sativa</i>-rocket, and <i>Raphanus sativus</i>-radish). Seeds were germinated at eight constant temperatures (from 5 to 35 °C) and five water potentials (<i>ψ</i>) in NaCl (from 0 to −1.2 MPa). Final germination percentage (FGP) was maximized at 15–20 °C in rocket, and at 20–25 °C in radish. As the temperature increased or decreased, germination was reduced and became less uniform, to a greater extent, at suboptimal temperatures in both species. Across water potentials, FGP values exceeding 50% at the highest temperature in radish indicated a greater tolerance than rocket to supraoptimal temperatures during germination. Across temperatures, FGP and germination speed in both species were progressively depressed as the water potential decreased. The adverse effects of NaCl progressively increased as the temperature moved away from its optimal value. Overall, rocket seeds were able to germinate well (>80%) at 20 °C at salinity levels down to −0.9 MPa, while radish seeds were able to germinate well (≥90%) at 25 °C at salinity levels down to −0.9 MPa. Salt stress tolerance was higher in rocket and radish at low and high temperatures, respectively. Both thermal time and hydrotime requirements were higher in radish because its seeds took longer to germinate. Thermal time and hydrotime may help to predict the germination capacity and time, once the temperature or water potential of the imbibition substrate is known. The findings of this study have important implications for the large-scale industrial production of microgreens.https://www.mdpi.com/2073-4395/15/2/361<i>Eruca sativa</i> Mill.<i>Raphanus sativus</i> L.germination indexesthermal timehydrotime
spellingShingle Stefania Toscano
Daniela Romano
Valeria Cafaro
Cristina Patanè
Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress
Agronomy
<i>Eruca sativa</i> Mill.
<i>Raphanus sativus</i> L.
germination indexes
thermal time
hydrotime
title Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress
title_full Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress
title_fullStr Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress
title_full_unstemmed Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress
title_short Annual Garden Rocket and Radish as Microgreens: Seed Germination Response to Thermal and Salt Stress
title_sort annual garden rocket and radish as microgreens seed germination response to thermal and salt stress
topic <i>Eruca sativa</i> Mill.
<i>Raphanus sativus</i> L.
germination indexes
thermal time
hydrotime
url https://www.mdpi.com/2073-4395/15/2/361
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AT valeriacafaro annualgardenrocketandradishasmicrogreensseedgerminationresponsetothermalandsaltstress
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