Guayule (Parthenium argentatum A. Gray) is an alternative source of natural rubber. Direct-seeding is critical to commercialization of guayule and quantifying variability in seed germination response to temperature is necessary. A thermogradient table was used to measure germination rates of the 44 most commonly available Parthenium accessions under 10 temperature gradients. The optimal temperature for seed germination ranged from 17.8–26.9 °C, with an average temperature of 21.8 °C. The sensitivity of seed germination to temperature range varied significantly among accessions. When compared with the highest germination rate at optimal temperature, relative germination rate at 10 °C and 35 °C represented low and high temperature tolerance for seed germination in guayule accessions, respectively. The two accessions with >70 % relative germination rate at 35 °C, R1109 and P. incanum (mariola), had the optimal temperature for germination above 26.6 °C. Six accessions with >70 % relative germination rate at 10 °C, 11591, R1110, PARL 935, CAL-3, 11605, and PARL 920, had a range of 17.8–21.7 °C optimal temperature for germination. This study indicates that guayule and other Parthenium accessions varied significantly in temperature requirements for seed germination. These temperatures can serve as a guide to seasonal timing for direct seeded field planting.

瓜尤勒（Parthenium argentatum A. Gray）是天然橡胶的替代来源。直接播种对愈创木瓜的商业化至关重要，因此有必要量化种子发芽对温度的响应变异性。使用热梯度表测量44种最常用的Parthenium的发芽率在10个温度梯度下收集。种子发芽的最佳温度范围为17.8-26.9°C，平均温度为21.8°C。不同品种的种子萌发对温度范围的敏感性差异很大。与最佳温度下的最高发芽率相比，在10°C和35°C时的相对发芽率分别代表了番石榴属植物种子对种子发芽的低温和高温耐受性。在35°C下相对发芽率> 70％的两个种，R1109和P. incanum（马里奥拉）的最佳发芽温度高于26.6°C。在10°C时相对发芽率> 70％的6个种，11591，R1110，PARL 935，CAL-3、11605和PARL 920的最佳发芽温度范围为17.8–21.7°C。这项研究表明，愈创木瓜和其他Parthenium品种在种子萌发的温度要求上差异很大。这些温度可以指导直接播种田间播种的季节时机。