水稻高效转化系统的建立

利用基因枪轰击和农杆菌介导两条途径转化水稻成熟胚、幼胚、幼穗诱导来源的愈伤组织．实验发现，外植体来源影响愈伤组织的诱导和转化．对于同一水稻品种，幼胚、幼穗在NB2培养基上比成熟胚易于诱导出胚性愈伤组织；转化中，无论是经农杆菌介导还是基因枪轰击，幼胚和幼穗来源的愈伤组织能以较高的转化频率获得转化体并再生成苗．同时，愈伤组织的诱导和转化效果也受基因型的影响．另外，转化途径对转化效率的影响较大，基因枪轰击比农杆菌介导转化频率高、再生频率强．并且，在轰击前6h至轰击后18h，将愈伤组织保持在附加20g／L甘露醇的培养基中，有利于转化率的提高．图2表3参17

ESTABLISHMENT OF EFFICIENT TRANSFORMATION SYSTEM IN RICE

Calli derived from mature embryos, young embryos and young panicles of 9 rice cultivars have been transformed. The results showed the factors which would affect the efficiency of calli induction and tranformation, such as the sources of calli and genotype. The induction and tranformation efficiencies were different for the calli derived from different explants. For the same rice cultivar,The induction and tranformation efficiencies of the calli derived from panicles were the highest and that from young embryos was higher than that from the mature embryos. Genotype was a smaller factor affecting induction and transformation efficiency. The methods which introducing alien DNA into receipt chromosome greatly affected transformation efficiency. The efficiency of microprojectile tranformation system was higher than that of Agrobacterium tumefaciens tranformation system. Furthermore,it would improve the transformation efficiency to keep the calli in the medium with mannitol(20 g/L)for a period from 6 h to 18 h before and after bombardment. Fig 2, Tab 3 , Ref 17