Evaluation on the Cold Tolerance of Rice at Booting Stage in Sanjiang Plain

In order to select cold tolerance resources of rice,the evaluation on cold tolerance of 349rice materials at booting stage was conducted from 2004to 2010.The results showed that there were 63materials reaching the first grade cold tolerance and 180materials reaching the second grade cold tolerance,which broadening the cold tolerance source of rice at booting stage.Taking Kongyu 131as the cold tolerance standard variety for 7 consecutive years,79 materials were selected for better cold tolerance than Kongyu 131at booting stage,in which 15materials combined well with high yield,8materials combined well with high quality,and 13materials were special rice.The results of cold tolerance of rice in field identification were directly affected by climate factors,taking Kongyu 131as standard material,the test materials were divided into group of insensitive to low temperatare and group of sensitive to low temperature.