Research on cold resistance breeding for Oenothera speciosa in Beijing

Coldresistance breeding for Oenothera speciosa in Beijing was carried out. Many times of bulk selection breeding, conventional cross breeding, radioactive breeding and ion implantation breeding were used in this study. Results showed that many times of bulk selection breeding could enhance cold resistance of O. speciosa which made the surviving rate of overwintering raised from 4.7% to 6.5% in four years. Cross breeding was performed with O.speciosa and another two coldresistance species, but there were no hybrid seeds during many years study. With the treatment of radiation dosage 200 Gy and 60Coradioactive to big seeds, the surviving rate of the seeds was 44.4%, while the surviving rate of overwintering could achieve 37.5%. The surviving rate of O.speciosa was 73.1% with the treatment of energy 35 MeV, injection dosage of 51010 Pcm-2, and Si ion implantation to small seeds, and the surviving rate of overwintering could achieve 55.3%. Notably, Surviving rate of overwintering was 6.5% before treatment. The best method to enhance cold resistance of O.speciosa is Si ion implantation, which made the highest surviving rate of overwintering in this study.