Abstract: ObjectiveEffects of ascorbic acid(Asc)and indole butyric acid(IBA)on pollen germination and growth of Nuomici litchi(Litch chinensis Sonn.)were studied to provide reference for high-yield cultivation of litchi.MethodNuomici litchi pollen of different batches were cultured in media adding Asc and IBA with various concentrations,then germination rate and pollen length were analyzed.ResultAsc with concentrations of 10.0-40.0,5.0-40.0 and 20.0-30.0 mg/L significantly(P<0.05,the same below)promoted the germination and growth of the first,second and third batches of pollen.In 20.0,5.0 and 30.0 mg/L Asc treatments,pollen germination rates the first,second and third batches were the highest respectively.In 30.0,10.0 and 20.0 mg/L Asc treatments,pollen lengths the first,second and third batches were the longest respectively.Adding 20.0 and 30.0 mg/L of Asc could promote pollen germination and pollen tube growth of every batch.Adding 2.5-20.0,2.5-5.0 and 2.5-20.0 mg/L IBA significantly promoted the germination and growth of Nuo-mici litchi first,second and third batches of pollen respectively.In 20.0,2.5 and 15.0 mg/L IBA treatments,pollen germi-nation rates of the first,second and third batches were the highest respectively. In 10.0,5.0 and 10.0 mg/L IBA treat-ments,pollen tube lengths of the first,second and third batches were the longest.Adding 2.5 and 5.0 mg/L of IBA pro-moted pollen germination and pollen tube growth of every batch.The results of correlation analysis showed that the first and second batch of Nuomici litchi pollen germination rate and pollen tube length was significantly positively correlated.ConclusionThe optimal concentrations of Asc and IBA that can promote different batches of pollen germination and pol-len tube growth of Nuomici litchi are different.Application of 5.0-10.0 mg/L Asc or 2.5-5.0 mg/L IBA before or after the opening of the second batches of Nuomici litchi flowers can promote pollination and fertilization to ensure high and stable yield.