Ácido giberélico y temperaturas cálidas de incubación como estimulantes de la germinación en semillas de kiwi amarillo (Actinidia chinensis var. chinensis)

The kiwifruit (Actinidia chinensis var. chinensis) is a deciduous fruit tree belonging to the Actinidiaceae family. Its industry in Mexico is still incipient, making it necessary to introduce new cultivars with diverse pulp colors and flavors. To achieve this, a population of seed-derived plants was used; however, these exhibited dormancy and low germination rates. This study aimed to evaluate pre-germination treatments to improve seed germination capacity. A completely randomized design with a factorial arrangement was applied, evaluating five concentrations of gibberellic acid (GA₃) [0, 1,000, 2,000, 4,000, and 6,000 ppm] in combination with three constant temperature levels (25, 30, and 35 °C) for 68 days. Prior to treatment application, seeds were stratified at 4 °C for 31 days and then immersed for 24 hours in their respective GA₃ solutions and water. Each experimental unit consisted of 50 seeds, with three replications. The variables evaluated included germination percentage (GP), mean germination rate (MGR), mean germination time (MGT), and days to dormancy release (DL), using ANOVA and Tukey’s test (P<0.05). Significant differences were found for all variables except MGT. The best results were obtained at 25 °C with any GA₃ concentration, where dormancy period was shortened (2.63 days), and both GP (6.35%) and MGR (0.5 seeds/day) increased. Constant temperatures above 30 °C negatively affected these variables.