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

Authors: XIAO, H - China Agricultural University; SONG, Q - China Agricultural University; Monaco, Thomas; YANG, H - China Agricultural University; RONG, Y - China Agricultural University

Submitted to: PeerJ
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2020
Publication Date: 4/7/2020
Citation: Xiao, H., Song, Q., Monaco, T.A., Yang, H., Rong, Y. 2020. Modeling the influence of temperature and water potential on seed germination of Allium tenuissimum. PeerJ. 8:. https://doi.org/10.7717/peerj.8866.
DOI: https://doi.org/10.7717/peerj.8866

Interpretive Summary: Successful crop establishment of Allium tenuissimum will depend on rapid and uniform seed germination. Our study aimed to characterize seed germination under various temperature and water potential levels and models predict maxiumum germination by hydrotime (HT) and hydrothermal time (HTT) analysis. Final germination percentage (FGP) increased within the range of 11 to 20 degrees C and the base (Tb) and optimum temperatures (To) for seed germination were 7.0 and 20.5 degrees C, respectively. Based on our models, we conclude that 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 degrees C and soil water potential less negative than -0.67 MPa offers information to forecast suitable settings to enhance crop production.

Technical Abstract: Allium tenuissimum is a widely distributed perennial herbaceous species in temperate grasslands. 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 (11, 15, 20, 24 and 28 degrees C) and water potential (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 degrees C, yet it declined within the range of 24 to 28 degrees C and generally decreased as water potential became more negative within each temperature setting. Maximum FGP was observed at 20 degrees C at all water potential settings and ranged from 55.0 plus or minus 5.3 to 94.8 plus or minus 1.4%. According to HT and HTT models, the base (Tb) and optimum temperatures (To) for seed germination were 7.0 and 20.5 degrees C, respectively. In addition, base water potential for the fraction of germination within the seed lot (base water potential (g)) shifted to 0 MPa as temperature increased from Tb to ceiling temperature (Tc). For obtaining 50% seed germination, base water potential (50) and Tc(50) were estimated to be -0.67 MPa and 27.2 degrees C, respectively. These values for Tb and base water potential (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 degrees C and soil water potential less negative than -0.67 MPa offers information to forecast suitable settings to enhance crop production.