Effect of Different Temperature Regimes on the Germination of Pseudolysimachion pusanensis (Y. N. Lee) Y. N. Lee Seeds

In this study, we determined the germination response in the seeds of the rare plant Pseudolysimachion pusanensis (Y. N. Lee) Y. N. Lee to different temperatures. P. pusanensis seeds were collected from the Baekdudaegan National Arboretum, South Korea, in November 2019, and dried. Dry seeds were placed at constant and alternating temperatures (5 degrees C, 10 degrees C, 15 degrees C, 20 degrees C, 25 degrees C, 30 degrees C, and 35 degrees C) to determine their germination percentage (GP). The seeds were exposed to 59 temperature combinations ranging from 5 degrees C to 43 degrees C using a thermal gradient plate. The photoperiod was set at 12:12 h (light:dark) and germination assays were performed five times a week. Subsequently, the seed GP and the number of days required to reach 50% of the germination (T-50) were determined. The highest final GP was 94.38%, with a T-50 value of 9.26 d at 15 degrees C. However, the mean germination time was 12.5 d at 15 degrees C, and linear regression using 1/T-50 revealed that the base temperature ranged from 2.69 degrees C to 4.68 degrees C. These results for P. pusanensis seeds stored in a seed bank provide useful data for the native plants horticulture industry and can also be utilized for storage management.

Automated summary

This study investigated the germination response of the rare plant Pseudolysimachion pusanensis seeds to different temperatures. It was found that the seeds had their highest germination percentage and shortest time to 50% germination at 15 degrees Celsius. The results provide valuable data for native plant horticulture and storage management.