Physiological and Germination Responses of Muskmelon (Cucumis melo L.) Seeds to Varying Osmotic Potentials and Cardinal Temperatures via a Hydrothermal Time Model

Ijaz Ul Haq; Sami Ullah; Fazal Amin; Muhammad Nafees; Wadood Shah; Baber Ali; Rashid Iqbal; Alevcan Kaplan; Mohammad Ajmal Ali; Mohamed S Elshikh; Sezai Ercisli

doi:10.1021/acsomega.3c01100

Physiological and Germination Responses of Muskmelon (Cucumis melo L.) Seeds to Varying Osmotic Potentials and Cardinal Temperatures via a Hydrothermal Time Model

ACS Omega. 2023 Sep 7;8(37):33266-33279. doi: 10.1021/acsomega.3c01100. eCollection 2023 Sep 19.

Authors

Ijaz Ul Haq¹, Sami Ullah¹, Fazal Amin¹, Muhammad Nafees¹, Wadood Shah², Baber Ali³, Rashid Iqbal^{4

5}, Alevcan Kaplan⁶, Mohammad Ajmal Ali⁷, Mohamed S Elshikh⁷, Sezai Ercisli^{8

9}

Affiliations

¹ Department of Botany, University of Peshawar, Peshawar 25120, Pakistan.
² Biological Sciences Research Division, Pakistan Forest Institute, Peshawar 25120, Pakistan.
³ Department of Plant Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
⁴ Department of Agronomy, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur Pakistan, Bahawalpur 63100, Pakistan.
⁵ Department of Agroecology-Climate and Water, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark.
⁶ Department of Crop and Animal Production, Sason Vocational School, Batman Universitesi, Batman 72060, Turkey.
⁷ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh11451, Saudi Arabia.
⁸ Department of Horticulture, Agricultural Faculty, Ataturk Universitesi, Erzurum25240, Turkiye.
⁹ HGF Agro, Ata Teknokent, Erzurum25240 ,Turkiye.

Abstract

Climatic changes have a direct negative impact on the growth, development, and productivity of crops. The water potential (ψ) and temperature (T) are important limiting factors that influence the rate of seed germination and growth indices. To examine how the germination of seed responds to changes in water potential and temperature, the hydrotime model and hydrothermal model (HTT) have been employed. The HTT calculates the concept of germination time across temperatures, between T_b-T_o, with alteration, and between T_b-T_c, in supra-optimal ranges. The seeds of Cucumis melo L. were germinated in the laboratory for a hydro-thermal time experiment. Seeds were sown in Petri dishes containing a double-layered filter paper at different osmotic potentials (0, -0.2, -0.4, -0.6, and -0.8 MPa) by providing PEG 6000 (drought stress enhancer) at different temperatures (15, 20, 25, 30, and 35 °C). The controlled replicate was treated with 10 mL of distilled water and the rest with 10 mL of PEG solution. Results indicated that the seed vigor index (SVI-II) was highest at 15 °C with 0 MPa and lowest at 30 °C with -0.2 MPa. However, the highest activity was shown at 15 °C by catalase (CAT) and guaiacol peroxidase (GPX) at (-0.6 MPa), while the lowest values of CAT and GPX were recorded for control at 35 °C with -0.8 MPa at 35 °C, respectively. Germination energy was positively correlated with germination index (GI), germination percentage (G%), germination rate index, seed vigor index-I (SVI-I), mean moisture content (MMC), and root shoot ratio (RSR) and had a negative correlation with mean germination rate, percent moisture content of shoot and root, CAT, superoxide dismutase, peroxidase ascorbate peroxidase, and GPX. In conclusion, thermal and hydrotime models correctly predicted muskmelon germination time in response to varying water potential and temperature. The agronomic attributes were found to be maximum at 30 °C and minimum at 15 °C.