Agrobacterium-mediated Genetic Transformation System Of Indica Rice 9311 And Huazhan

Rice transgenic technology is an important tool to promote rice molecular biology research and precision breeding.Agrobacterium-mediated transgenic technology has become the mainstream method for rice genetic transformation.Nevertheless,limited by genotype,the genetic transformation efficiency of typical indica rice is still quite low.In this study,the effects of combination of macro element,micro element,organic matter and carbon source,phytohormone concentration,infection medium,acetosyringone(AS)concentration and photoperiod on genetic transformation efficiency of recalcitrated indica rice varieties 9311 and Huazhan were investigated.The main results of this study were showed as follows:(1)MS macro element,B5 micro element,N6 organic matter and maltose were the best combination for 9311 tissue culture.MS macro element,MS micro element,MS organic matter and maltose were the best combination for Huazhan tissue culture.(2)Adding 0.5 mg/L BAP or 1.5 mg/L KT into the induction medium could significantly improve the regeneration rate of 9311 and Huzhan tissue culture,up to more than 70.0%.(3)The transformation efficiency with 100μM AS in the infection solution was higher than that with 200μM AS.(4)Photoperiod experiments suggested that different photoperiod strategies should be adopted for 9311 and Huazhan transformation.9311 transformation efficiency reached the highest,6.0%-6.4%,under continuous darkness at the induction and selection stages and continuous light at the differentiation stage.Huazhan transformation efficiency reached the highest,5.0%-7.5%,under 12 h photoperiod at all stages.Collectively,the present study optimized tissue culture and genetic transformation system of recalcitrant indica rice varieties 9311 and Huazhan.(5)The calli of Huazhan were infected with A and B infection medium,their average resistant callus frequency were 83.0% and 78.1%,respectively.The average transformation frequency was 9.7% and 7.6%,respectively.Statistical analysis showed that there was no significant difference in transformation frequency between A infection medium and B infection medium.Our methods could also be applied to the genetic transformation of other related indica rice genotypes.