Establishment And Application Of A Comprehensive Assessment System For Cold Resistance In Denphal-Group Dendrobium Cultivars

The objective of this study was to establish a comprehensive assessment system for cold resistance in Denphal-group Dendrobium cultivars, and evaluation of cold resistance of 35 Denphal-group Dendrobium cultivars. The concentration of soluble sugar, soluble protein, free proline, malondialdehyde, chlorophyll, and LT50 of two Denphal-group Dendrobium cultivars were measured under low temperature, and significance analysis, correlation analysis, principal component analysis, and weight analysis of these indicators were conducted, and then a comprehensive assessment system was constructed using the membership function and weight of indicators methods. Secondly, the cold resistance of 35 cultivars was assessed using the comprehensive assessment system. Under our experimental conditions, free proline, malondialdehyde, and chlorophyll were significantly correlated with LT50 at 0.05-level. The principal component analysis and weight analysis indicated that the most significant factor affecting cold resistance was free proline, followed by MDA and chlorophyll, indicating that the three indicators could be used to determine cold resistance in Denphal-group Dendrobium cultivars. The cold resistance evaluation of 35 cultivars showed that the most cold-resistant cultivar was 'Sophie Bonnie', and the most sensitive cultivar was 'More Red x Thailand'. These results demonstrated that the three indicators of free proline, MDA and chlorophyll could be used to determine cold resistance in Denphal-group Dendrobium cultivars.