Identification and Evaluation on the Multi-resistance of Introduced Rice Varieties and its Utilization

3431,1301,and 2011 IRRI-provided varieties from International Rice Blast, Bacterial Blight and Brown Planthopper Nurseries were determined from 1979 to 1993.The results showed that, the varieties from rice blast nursery,0.1-2.3 scale occupied 437,131 and 121 respectively;from bacterial blight nursery,1,3 and 5 scale occupied 214, 372and 301 respeltively;from brown planthopper nursery occupied 231,374 and 597 respectively,In determined varieties,12 from rice blast nursery, 8 from bacterial blight nursery and S from brown planthopper nursery have relative- ly strong and wide-ranging resistance which may be considered to be used as parent materials in rice breeding.