为探讨自然越冬条件下茶树〔Camellia sinensis （Linn.） O. Ktze.〕叶片的生理生化指标和解剖结构变化，以种植于南京的茶树品种‘龙井长叶’（‘Longjingchangye’）的10年生植株为研究对象，对自然越冬期间（2012年11月15日至2013年3月31日）其叶片的叶绿素、可溶性蛋白质、可溶性糖、游离脯氨酸和丙二醛（MDA）含量，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性，以及上表皮、下表皮、栅栏组织和海绵组织厚度及上表皮厚度与海绵组织厚度的比值进行了比较分析。结果表明：自然越冬期间，叶片的叶绿素含量随时间推移呈现先降低后升高的变化趋势，而叶片的可溶性蛋白质、可溶性糖、游离脯氨酸和MDA含量以及SOD、CAT和POD活性则总体上呈现先升高后降低的变化趋势，并且均在2013年1月15日达到其各自的最低值或最高值。与入冬前相比，越冬后叶片的叶绿素和可溶性糖含量显著降低，MDA含量略降低，可溶性蛋白质含量显著升高，游离脯氨酸含量及SOD、CAT和POD活性均略升高。自然越冬期间，叶片的上表皮、下表皮、栅栏组织和海绵组织厚度随时间推移总体上呈现先降低后升高的变化趋势，上表皮和栅栏组织厚度在2013年2月15日达到最低值，而下表皮和海绵组织厚度则在2013年1月30日达到最低值；上表皮厚度与海绵组织厚度的比值呈波动变化趋势。与入冬前相比，入冬后叶片的上表皮、下表皮、栅栏组织和海绵组织厚度均显著降低，而上表皮厚度与海绵组织厚度的比值略降低。研究结果显示：自然越冬条件下，茶树具有一定的耐寒能力，为了减轻低温对其机体的伤害可通过增加可溶性蛋白质、可溶性糖和游离脯氨酸合成及提高相关抗氧化酶活性来调解越冬期间的代谢平衡。

In order to understand the changes in physiological and biochemical indexes and anatomical structure of leaf of Camellia sinensis （Linn.） O. Ktze. under natural overwintering condition， ten-year-old plants of C. sinensis ‘Longjingchangye’ planted in Nanjing were used as materials， contents of chlorophyll， soluble protein， soluble sugar， free proline and malondialdehyde （MDA）， activities of superoxide dismutase （SOD）， catalase （CAT） and peroxidase （POD）， thicknesses of upper epidermis， lower epidermis， palisade tissue and spongy tissue, and ratio of upper epidermis thickness to spongy tissue thickness of its leaf were compared and analyzed during natural overwintering period （from November 15th， 2012 to March 31st， 2013）. The results show that during natural overwintering period， chlorophyll content in leaf appears the trend of decreasing firstly and then increasing as time goes on， while contents of soluble protein， soluble sugar， free proline and MDA， and activities of SOD， CAT and POD in leaf generally appear the trend of increasing firstly and then decreasing， and all of them reach their corresponding lowest or highest values on January 15th， 2013. Compared with before winter， contents of chlorophyll and soluble sugar in leaf decrease significantly， content of MDA decreases slightly， that of soluble protein increases significantly， that of free proline and activities of SOD， CAT and POD increase slightly after winter. During natural overwintering period， thicknesses of upper epidermis， lower epidermis， palisade tissue and spongy tissue appear the trend of decreasing firstly and then increasing， those of upper epidermis and palisade tissue reach the lowest values on February 15th， 2013， while those of lower epidermis and spongy tissue reach the lowest values on January 30th， 2013； ratio of upper epidermis thickness to spongy tissue thickness appears a fluctuation trend. Compared with before winter， thicknesses of upper epidermis， lower epidermis， palisade tissue and spongy tissue of leaf all decrease significantly， while ratio of upper epidermis thickness to spongy tissue thickness decreases slightly after winter. It is suggested that under natural overwintering condition， C. sinensis has some cold tolerance ability. In order to reduce the damage of low temperature to its body， it is possible to mediate the metabolism balance by increasing syntheses of soluble protein， soluble sugar and free proline， and improving related antioxidant enzyme activities during natural overwintering period.