Comparison of the intrinsic optimum temperatures for seed germination between two bamboo species based on a thermodynamic mode

Alpine plants usually experience lower ambient temperatures than non-alpine plants.However, it is still not known whether the former have lower temperature thresholds andlower physiological optimum temperatures for development than the latter. We studiedtwo native Chinese bamboo species that have different vertical distributions: Chimono-bambusa utilis, which typically grows at altitudes of 1400-2200 m, and Phyllostachys edulis(i.e., moso), which typically grows at altitudes of 40O-800 m. The seed germination timesof both species at eight temperatures from 16 to 30C at 2 °C increments were observed.Athermodynamic model was used to calculate the intrinsic optimum temperature andupper developmental threshold for development of each of these two species, and a linearmodel was used to calculate their lower developmental threshold and the sum of effectivetemperatures required for completing seed germination.