The Evaluation Of Cold Resistance On Camellia Oleifera And The Effect Of Cacl₂on Cold Resistance Of Camellia Oleifera

Camellia(Camellia oleiferaAbels)belongs to Theaceae. It is one of major oil-bearing plants withthe highest productive vaule. Due to the poor cold tolerance, its extension and utilization islimited in the colder regions of China. In order to provide theoretical basis for selecting thestronger cold tolerance specie and enhancing its cold tolerance, three varities of Camellia werechoosen in the study. Different low temperature and concentrations of CaCl₂were taken asinfluencing factors to investigate the physiological and biochemical indexes of the leaves for thethree varities of Camellia. The results were as follows:(1) There were signifcant differences in physiological and biochemical indexs among the threevarieties of Camellia. Camellia-53possessed the highest proline(pro),soluble sugar,soluble proteincontent and SOD,POD activities with the lowest semilethal temperature and MDA content. Thephysiological and biochemical indexs showed that cold tolerance of Camellia-53was best. Contraryto Camellia-53, Camellia-23was found to have the lowest pro,soluble sugar,soluble proteincontent and SOD,POD activities, but its semilethal temperature and MDA content was highestThat showed that the cold tolerance of Camellia-23was poorest. The physiological andbiochemical indexs of Camellia-3lied between Camellia-53and Camellia-23. The cold toleranceof three varities of Camellia obtaind by fuzzy subordination method in descending order wasCamellia-53>Camellia-3>Camellia-23.(2) CaCl₂addition had a significant influence on cold tolerance of the three varietties ofCamellia. It was obsered that semilethal temperature and MDA content was decreased by CaCl₂addition, meanwhile Fpro,soluble sugar,soluble protein content was increased and SOD,PODactivity was improved, which reflected an improved cold-tolerance of Camellia. The reductionextent of semilethal temperature and MDA content by0.2%CaCl₂addition was larger than thatof0.1%CaCl₂addition, the increase extent of osmotic adjustment substance and protectiveenzyme was also larger than0.1%CaCl₂addition. In a word effect of0.2%CaCl₂is better than0.1%CaCl₂.in improving cold-tolerance of Camellia(3)The result of SDS-PAGE showed that low temperature induced antifreeze proteinexpression, CaCl₂addition increased the content of the antifreeze protein of Camellia to someextent.