Comparative Analysis On Cold Resistance Of Introduced Tea Varieties In Southern Shaanxi Tea Area

In order to study the winter hardiness of tea tree in Shannan, the survival rate,Overwintering mortality rate, Bud phonology, Freezing area in micro thermal climate of threeintroduced variety have been investigated. By artificial low temperature stress method, theElectrolyte leakage, MDA content, proline content, Soluble sugar content, POD and SODactivities have been tested. Tea tree’s physiological and biochemical indicators under lowtemperature stress were analysised, using principal component correlation matrix for thecomprehensive analysis of all factors.The results show that CK cultivar’s field adaptation is better than three cultivars, but forsurvival rate during winter, the latter is better. Phenophase of introduced tea tree is3-7daysearlier than CK. All four varieties are not very different in enduring frozen injury.Using Logistic regression equation, all four varieties’ relative conductivity and stresstemperature have been calculated. Drought resistance is nongkangzao> wuniuzao>fudingdabai> yuanxiaolv.Relative conductivity, MDA content, POD activity can be main index of tea tree’s coldresistance. Relative conductivity could be a basic index and MDA content, POD activitycould be additional index.Under artificial low temperature stress, tea tree’s relative conductivity, MDA content,proline content, Soluble sugar content, POD and SOD activities all raised in different levels.The better cold tolerance is, the width of rising will be. nongkangzao’s range of variation isthe highest while the yuanxiaolv’s is the lowest.Accorading to the regulatory of temperature change of Shannan area, nongkangzao,wuniuzao, fudingdabai could be cultivated in wide areas and yaunxiaolv could be cultivatedas late ripening variety due to it needs additional protective measures in winter.