Gamma Ray Application for Increasing Kemenyan Toba (Styrax sumatrana) Seed Viability

: Kemenyan toba ( Styrax sumatrana ) is the identity trees for Tapanuli community in North Sumatra, Indonesia. These non-timber forest products have been cultivated for generations. Over the past decade, the incense productivity have been decreasing due to the lower interest of farmer to cultivate kemenyan. The another reason also causing by longer germinate time so that the farmers difficulty obtaining high quality seedlings for replanting the old unproductive trees. Accelerate germination time through improving seed viability and genetic engineering were prospective ways for increasing kemenyan productivity. The objective of this research was to determine the effectiveness of gamma irradiation techniques application for increasing the viability of Kemenyan toba seeds. Randomized completely design, with 5 levels of radiation dose those were, control 0 Gy, 10 Gy, 20 Gy, 30 Gy, and 40 Gy with 4 replications was used in this research. The results showed that increasing the intensity of irradiation shortens the germination time. The highest germination rate occurred on day 61 on the intensity of irradiation 40 Gy whereas the control was day 197. The treatment of irradiation affected the germination. However, increasing irradiation intensity decreasing the sprouting ability. On seeds without irradiation, sprouting percentage reach an average of 83.8%. The germination rate was not different compared to the seeds that received irradiation treatment with intensities of 10 and 20 Gy with sprout power of 75.0% and 57.5%. It means that the low dose of gamma ray irradiation can be used to increase the viability and vigor of Kemenyan