【Objective】Evaluation for rice blast and molecular detection of backcross introgression lines would supply elite parents and provide a theoretical basis to rice breeding for disease resistance. 【Method】Restorer line C253 and G649 were used as the recurrent parent to cross with 3 rice varieties,respectively. In the end,6 backcross ILs populations were obtained. Evaluation of ILs population for rice blast resistance was carried out using the identification of natural infection in open field and artificial ino...