In-vitro Seed Germination Biology of Milicia Excelsa Population Collected from Benchi-Maji Zone, South Western Ethiopia
Abstract Background: In Ethiopia, species used for timber production are limited to few species. So, it is becoming necessary to find innovative ways of maintaining and improving the genetic quality of species such as Milicia excelsa by domesticating them into a wider scale of ecological and social environment. Hence, the main objective of this study was to investigate the seed germination biology and behavior of Milicia excelsa under in-vitro laboratory conditions so as to promote the domestication and establishment of seed production areas (SPA) in-situ. Methods: Seeds collected from Benchi district of Benchi-Maji zone of southwestern Ethiopia were subjected to germination biology in-vitro to determine the germination responses of M. excelsa seeds under laboratory conditions. So, a total of 1200 seeds were randomly selected, treated and prepared using four treatments procedures with six replications for paper method and 3 replications for sand method, and tested using paper methods in CRD design. So, 600 seeds were tested using paper and sand methods each where 25 seeds were tested for each replication in paper and 50 seeds for each replication in sand method. The germination process was lasted between 19 March 2020 and 15 May 2020. Result: The mean germination percentage of seeds of M. excelsa was noticed to be lower than 20%. This is below the expected (45%) germination rate of mature and healthy seed lot. Overall, seeds that were not treated using any pre-sowing treatments has shown relatively better germination percentage (19%) followed by seeds rubbed by hand (15%). Analysis of one-way t-test shows that the effects untreated (control –T1) and rubbing by hand treatments (T4) is significant at p < 0.05 compared to the effects of the other pre-sowing treatments (T2- seeds only washed with normal tap water, and T3- seeds washed and soaked in hot water for 15 minutes) on the germination capability of seeds of M. excelsa . However, no significance difference was observed between control (T1) and hand scarification (T2). Conclusions: The average germination of M. excelsa seeds combined for all treatments is lower than 20% which is lower germination when comparing with other similar research reported in other countries. Therefore, it required to include and test other pre-sowing treatments including tissue culture micro-propagation of seeds to maximize the germination of M. excelsa seeds helping to get enough seedlings required for the domestication project.