Modeling the influence of temperature and water potential on seed germination of Allium tenuissimum L

Hong Xiao; Helong Yang; Thomas Monaco; Qian Song; Yuping Rong

doi:10.7717/peerj.8866

Modeling the influence of temperature and water potential on seed germination of Allium tenuissimum L

PeerJ. 2020 Apr 7:8:e8866. doi: 10.7717/peerj.8866. eCollection 2020.

Authors

Hong Xiao¹, Helong Yang¹, Thomas Monaco², Qian Song¹, Yuping Rong¹

Affiliations

¹ Beijing Key Laboratory of Grassland Science, College of Grassland Science and Technology, China Agricultural University, Beijing, China.
² USDA-ARS Forage and Range Research Laboratory, Utah State University, Logan, UT, United States of America.

Abstract

Allium tenuissimum L. is a widely distributed perennial herbaceous species in temperate and desert steppes. Relative to other wild Allium species, it produces unique sweet flavors, more biomass in arid and cold environments, and has generated greater interest for crop production. Successful crop establishment, however, will depend on rapid and uniform seed germination. Our study aimed to characterize seed germination of A. tenuissimum under various temperature regimes (11, 15, 20, 24 and 28 °C) and water potential levels (0, -0.2, -0.4 and -0.6 MPa), and model germination by hydrotime (HT) and hydrothermal time (HTT) analysis. Final germination percentage (FGP) increased within the range of 11 to 20 °C, yet it declined within the range of 24 to 28 °C and generally decreased as water potential became more negative within each temperature setting. Maximum FGP was observed at 20 °C at all water potential settings and ranged from 55.0 ± 5.3 to 94.8 ± 1.4%. According to HT and HTT models, the base (T _b) and optimum temperatures (T _o) for seed germination were 7.0 and 20.5 °C, respectively. In addition, base water potential for the fraction of germination within the seed lot (Ψ_b(g)) shifted to 0 MPa as temperature increased from T _b to ceiling temperature (T _c). For obtaining 50 % seed germination, Ψ_b(50) and T _c(50) were estimated to be -0.67 MPa and 27.2 °C, respectively. These values for T _b and Ψ_b(50) suggest seed germination of A. tenuissimum is both cold and drought tolerant and suitable for production in semi-arid regions. Our characterization of the ideal sowing conditions for A. tenuissimum, i.e., 20.5 °C and soil water potential less negative than -0.67 MPa offers information to forecast suitable settings to enhance crop production.

Keywords: Allium tenuissimum; Crop production; Drought tolerant; Hydrothermal time model; Seed germination.

Grants and funding

This research was supported by the National Key Research and Development Program of China (No. 2016YFC0500603), the National Natural Science Foundation of China (No. 31772653) and National Natural Science Foundation of China (No. 31472136). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.