Determination and evaluation of cold resistance of 5 poplar clones

Used 5 poplar clones as the experimental materials,the conductivity and K+-leakage of dormant one-year-old cuttings which had been treated with different low temperature were determined by electro-conductivity gauge and atomic absorption spectrometer.Data of two indexes were treated with the single factor variance analysis and multiple comparison.Regression models were established about low temperature (T) to the conductivity or the K+-leakage of the clones.According to the result,the median lethal temperature of tissue of all clones is -25℃～-32℃.The cold resistance abilities of the clones were comprehensively compared according the studied indices.The results showed that there were obvious differences among the clones of the ability of cold resistance.The order of the ability of cold resistance on 5 poplar clones was populus.deltoides cl.'57'×P.bolleanaPopulus alba×P.glandulosaPopulus albaPopulus bolleanaPopulus tomentosa-30.