自然越冬过程中3个茶树品种的生理特性变化及抗寒性评价

Change in physiological characteristics and cold resistance evaluation of three cultivars of Camellia sinensis during natural overwintering period

以茶树〔Camellia sinensis(Linn.) Kuntze〕品种‘舒茶早’(‘Shuchazao’)、‘乌牛早’(‘Wuniuzao’)和‘平阳特早’(‘Pingyangtezao’)为实验材料,分析了自然越冬过程中(2011年10月至2012年3月)茶树叶片主要渗透调节物质(可溶性糖、可溶性蛋白质、热稳定蛋白质和脯氨酸)含量、抗氧化酶(SOD、CAT和POD)活性、PSⅡ原初光能转化效率(Fv/Fm)和总叶绿素含量的变化,并应用主成分分析结合隶属函数法对3个茶树品种抗寒性进行综合评价。结果表明:自然越冬期3个茶树品种叶片生理指标随时间推移呈规律性变化,越冬期(12月和1月)与越冬前期(10月)、越冬后期(2月和3月)各指标总体上差异显著,且品种间各指标也有一定差异。可溶性糖、可溶性蛋白质、热稳定蛋白质和脯氨酸含量以及SOD活性均呈先升后降的变化趋势,且峰值多出现在12月或2月;CAT和POD活性、Fv/Fm值和总叶绿素含量则呈先降后升的变化趋势,且均在1月降至最低。主成分分析结果显示:第1主成分(X1)包括可溶性糖含量、SOD活性、CAT活性、POD活性、Fv/Fm和总叶绿素含量,贡献率达到57.97%;第2主成分(X2)包括可溶性蛋白质含量、热稳定蛋白质含量和脯氨酸含量,贡献率达到26.89%。综合评价结果显示:自然越冬期3个茶树品种抗寒性的综合评价值均随时间推移呈先升后降的变化趋势,且均在12月达到最高,据此判断3个茶树品种中‘舒茶早’的抗寒性最强、‘乌牛早’的抗寒性最弱,‘平阳特早’的抗寒性介于二者之间。研究结果显示:在自然越冬过程中供试3个茶树品种的抗寒性与其生理指标变化及生长表现一致,表明综合评价法可用于茶树抗寒性评价。

Taking cultivars ‘Shuchazao’, ‘Wuniuzao’and ‘Pingyangtezao’of Camellia sinensis （Linn.） Kuntze as experimental materials, changes in main osmoregulation substance （ soluble sugar, soluble protein, heat-stable protein and proline） content, antioxidant enzyme （SOD, CAT and POD） activity, the maximum quantum efficiency of PSII（Fv / Fm ） and total chlorophyll content in leaf of C. sinensis during natural overwintering period （from Oct. 2011 to Mar. 2012） were researched, and cold resistance of three cultivars of C. sinensis was comprehensively evaluated by principal component analysis combined with subordinate function method. The results show that during natural overwintering period, there is a regular change in physiological indexes in leaf of three cultivars with the passage of time, and difference in each index among overwintering stage （Dec. and Jan.）, pre-winter stage （Oct.） and post-winter stage （Feb. and Mar.） is generally significant and there is a certain difference in each index among different cultivars. Contents of soluble sugar, soluble protein, heat-stable protein and proline and SOD activity increase firstly and then decrease, and the peak value mostly appears at Dec. or Feb. While CAT and POD activities, Fv / Fm value and total chlorophyll content decrease firstly and then increase, and all appear the minimum at Jan. The result of principal component analysis shows that the first principal component （X1） includes soluble sugar content, activities of SOD, CAT and POD, Fv / Fm and total chlorophyll content with the contribution rate of 57. 97% , and the second principal component （ X2） includes contents of soluble protein, heat-stable protein and proline with contribution rate of 26. 89% . The result of comprehensive evaluation shows that during natural overwintering period, the comprehensive evaluation value of cold resistance of three cultivars all increases firstly and then decreases with the passage of time, and all reach the maximum at Dec. According to this evaluation, cold resistance of cultivar ‘Shuchazao’ is the strongest in three cultivars, that of cultivar ‘Wuniuzao’ is the weakest, and that of cultivar ‘ Pingyangtezao’ is between them. It is suggested that during natural overwintering period, cold resistance of three cultivars tested is consistent with physiological index change and growth appearance, as a result, comprehensive evaluation method can be used to evaluate cold resistance of C.sinensis.