Screening of optimal in vitro germination culture media and storage conditions of Barringtonia racemose pollen

In order to screen out the culture medium suitable for the in vitro germination of Barringtonia racemosa pollen and the optimal conditions for the storage of B. racemosa pollen, this study took the pollen of B. racemosa as the research object. Single-factor and orthogonal in vitro germination experiments were carried out by using different concentrations of sucrose, H₃BO₃, CaCl₂ and different levels of culture temperature. The results of determining pollen viability by the acetic carmine method, I₂-KI method, TTC method, MTT method and in vitro germination method were compared, and it was determined that the best methods for determining the viability of B. racemosa pollen were the MTT method and the in vitro germination method. The results showed that the optimal culture medium for the in vitro germination of B.racemosa pollen was sucrose at 50 g/L, H₃BO₃ at 100 mg/L, CaCl₂ at 25 mg/L, and the pollen germination rate was 18.53%, with the culture temperature being 37 ℃. The germination rates of both dried and undried pollen under different storage temperatures gradually decreased with the storage time. Under the condition of −20 ℃ and after the pollen was dried, the B. racemosa pollen still had a germination rate after being stored for 12 units of time. The results of this study are of great significance for the population conservation, cross-breeding, and long-term preservation of germplasm of B. racemosa.