A Modified Thermal Time Model Quantifying Germination Response to Temperature for C3 and C4 Species in Temperate Grassland

Agriculture

Hongxiang Zhang²  Yu Tian¹  Daowei Zhou² 

[1] Animal Science and Technology College, Jilin Agricultural University, Changchun 130118, China; E-Mail:;Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012, China; E-Mail:

关键词: germination rate;    base temperature;    thermal time constant;    seed size;   

DOI  :  10.3390/agriculture5030412

来源: mdpi

【 摘 要 】

Thermal-based germination models are widely used to predict germination rate and germination timing of plants. However, comparison of model parameters between large numbers of species is rare. In this study, seeds of 27 species including 12 C₄ and 15 C₃ species were germinated at a range of constant temperatures from 5 °C to 40 °C. We used a modified thermal time model to calculate germination parameters at suboptimal temperatures. Generally, the optimal germination temperature was higher for C₄ species than for C₃ species. The thermal time constant for the 50% germination percentile was significantly higher for C₃ than C₄ species. The thermal time constant of perennials was significantly higher than that of annuals. However, differences in base temperatures were not significant between C₃ and C₄, or annuals and perennial species. The relationship between germination rate and seed mass depended on plant functional type and temperature, while the base temperature and thermal time constant of C₃ and C₄ species exhibited no significant relationship with seed mass. The results illustrate differences in germination characteristics between C₃ and C₄ species. Seed mass does not affect germination parameters, plant life cycle matters, however.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.