Radiohormetic effect on the germination of Pinus pseudostrobus Lindl. seeds irradiated with linear accelerator

Abstract

Pinus pseudostrobus Lindl. is one of the most widely propagated species in Mexico for reforestation, agroforestry, and commercial timber plantations because of the quality of its wood and its rapid growth. Among the physical and chemical methods to improve the effectiveness of germination, stimulation with radiation has shown positive effects on seed germination and seedling growth in several species. However, there are not many studies that have explored the radiohormetic effect on germination, survival, and seedling quality in conifers. Therefore, the present study was carried out with the objective of evaluating the radiohormetic effects of the use of low doses of linear accelerator on the germination capacity, growth, and quality of seedlings as well as the chlorophyll content of P. pseudostrobus for the purpose of reforestation and the establishment of forest plantations. A total of 720 seeds were taken to be irradiated with doses of 0, 0.5, 1.5, 1.5, 3, 5, and 7.5 Gy, in the linear accelerator Elekta Synergy Platform. For each dose, four replicates of 30 seeds each were used. It was determined that all the doses used increased the number of germinated seeds and showed an increase in seedling growth with respect to the control. The plant quality indexes showed that the doses of 0.5, 1.5, and 3.0 Gy contributed most to obtaining plants with larger aerial and root parts, but with a balanced conformation and a great capacity for the formation of new roots, which will help to present better levels of survival.