Response of Different Sugarcane Genotypes to Low Temperature and Evaluation for Cold Tolerance of Sugarcane
In order to establish an integrated assessment system in cold resistance of sugarcane and to screen the cold tolerant genotypes,4 elite sugarcane lines(08-56,08-441,08-572 and 08-1497),which were part of breeding materials from Sugarcane Research Institute,Guangxi Academy of Agricultural Sciences,and 2 main varieties(ROC22 and ROC16),were employed to examine the cold resistance at seedling stage based on morphological characteristics,physiological and biochemical indices and photosynthetic traits in this experiment.The plant height and pseudo-stem diameter were decreased in low-temperature treatment than that in room temperature treatment.Different degrees of wilting leaves were observed.MAD content,cellular membrane permeability,proline content and Fo value were increased.SPAD values,POD(peroxidase)activity,net photosynthetic rate,stomatal conductance,and Fv/Fm values were declined in low temperature treatment.Variation of SOD(Superoxide dismutases)activity were different in different sugarcane genotypes.The evaluation score for each sugarcane cultivar was calculated by the method of polar ordination.According to the scores,ROC22 showed the lowest cold tolerance and line 08-56 showed the highest,while the tolerance of all the other lines was higher than that of ROC22 but lower than that of ROC16.