LAUSR

The role of seed imbibition and light during germination are not known for the critically endangered Serianthes nelsonii Merr. Scarified seeds were pre-soaked in gibberellic acid (GA3) up to 300 mg/L and nitrate solutions of 3000 mg/L to determine if germination was influenced by these treatments. Scarified and imbibed seeds were incubated in high red:far red and low red:far red light to determine the influence of light quality on germination traits. The GA3 and nitrate treatments did not influence germination percentage or timing, but did increase the height of newly emerged seedlings. Moreover, GA3 extended the longevity of cotyledons and shortened the window of time that seedlings required to resume height growth. These growth responses were not sustained, and all seedlings reached heights of 30 cm at a similar number of weeks. The light treatments did not influence any of the germination response traits. The results indicate that imbibing seeds with chemical solutions and providing light in a range of light quality treatments exerted a minimal influence on S. nelsonii seed germination behaviors. Imbibing seeds with water and germinating in darkness is sufficient for achieving the germination of this endangered tree species.