Quantifying Temperature and Osmotic Stress Impact on Seed Germination Rate and Seedling Growth of Eruca sativa Mill. via Hydrothermal Time Model

Sheharyar Khan; Abd Ullah; Sami Ullah; Muhammad Hamzah Saleem; Mohammad K Okla; Abdulrahman Al-Hashimi; Yinglong Chen; Shafaqat Ali

doi:10.3390/life12030400

Quantifying Temperature and Osmotic Stress Impact on Seed Germination Rate and Seedling Growth of Eruca sativa Mill. via Hydrothermal Time Model

Life (Basel). 2022 Mar 9;12(3):400. doi: 10.3390/life12030400.

Authors

Sheharyar Khan¹, Abd Ullah^{2

3

4}, Sami Ullah¹, Muhammad Hamzah Saleem⁵, Mohammad K Okla⁶, Abdulrahman Al-Hashimi⁶, Yinglong Chen⁷, Shafaqat Ali^{8

9}

Affiliations

¹ Department of Botany, University of Peshawar, Peshawar 25120, Pakistan.
² Xinjiang Key Laboratory of Desert Plant Roots Ecology and Vegetation Restoration, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
³ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
⁴ Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele 848300, China.
⁵ College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
⁶ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
⁷ The UWA Institute of Agriculture, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6001, Australia.
⁸ Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan.
⁹ Department of Biological Sciences and Technology, China Medical University, Taichung City 40402, Taiwan.

Abstract

Germination models are quite helpful in predicting emergence times, dormancy periods, and their applications in crop management. This study investigated the germination behaviors of Eruca sativa Mill. in response to fluctuations in temperatures (T_s) and water potentials (ψ_s). Germination percentage (GP) increased 95% with rising temperature within the range of 20-30 °C, and decreased 25% at 5 °C. Moreover, each ψ and T resulted in a decrease in GP as ψ decreased. Further, we noted that the θT1 value was substantially high at 30 °C and in (0 MPa), whereas the θT2 value was maximum at 10 °C (-0.02 MPa) and it decreased with decreasing Ψ. The maximum hydrothermal time constant (θHTT) and hydrotime (θH) values were obtained at 10 and 30 °C, respectively. In addition, a linear increase in the GR_(g) pattern was observed at T_b and a decrease below the T_o. The calculated cardinal T_s was 5 °C for the base T, and 30 °C for both the optimum and ceiling T. The germination characteristics were higher at 30 °C having (0 MPa). Therefore, using cardinal temperatures, germination results, and the hydrothermal time model (HTT) could reveal the independent and interactive impacts of both T and the Ψ on the response of seed germination subjected to diverse environmental conditions.

Keywords: Eruca sativa; cardinal temperature; germination; hydrothermal constant; water stress.