【作者】 段宝利；

【导师】 张文辉； 胡景江；

【作者基本信息】 西北农林科技大学 ， 植物学， 2003， 硕士

【摘要】 本研究以栓皮栎4个种源3年生幼苗为实验材料(巴山北坡（种源1）、河南伏牛山（种源2、秦岭北坡（种源3）、陕西黄龙林区（种源4），分别在大田和水分控制条件下，进行了水分平衡参数、光合作用及保护酶系统抗氧化作用相关参数测定，比较分析了4种源的生理生态以及生长特征，在对种源生理和生长差异进行研究的基础上，建立了抗旱性筛选的指标体系，对不同种源进行了抗旱性评价，获得了如下主要结论： 1．栓皮栎不同种源的水分平衡机理、抗旱特性等生理生态学特征是由于长期进化适应的结果，与其起源和所处的生境条件相适应。不同种源生理生态学差异在形态、生理生态、适应能力方面具有稳定的遗传特性，进行子代苗期测定具有一定的理论依据和实践意义。 2．4种源对干旱适应特性和水分平衡机理有明显差异。在干旱胁迫条件下，种源4具有较大的单位叶面积干重，很强的保水力，较低的蒸腾作用；具有较坚硬、较厚实的细胞壁来保持体内水分，维持较高的水势和膨压；抗氧化能力强是其有较强抗旱性的重要原因之一；严重水分亏缺情况下，具有低生产但水分利用率高的生理生态特点，耐旱特性较突出；种源1叶水势、细胞弹性、抗旱生产力及水分利用率大幅度下降，且较早关闭气孔以减少水分丧失，其活性氧消除系统中各部分清除能力失衡过快，H₂O₂的累积迅速，膜透性提高，耐旱特性相对较差；种源3蒸腾低、地下／地上生物量比值大、渗透调节能力强，抗氧化能力仅次于种源4，自身潜在的抗旱性强，在严重干旱条件下延迟气孔关闭并保持一定的同化作用，仍能积累一定的干物质；种源2的水势和持水力较低，其对水分适应性和抗旱生产力次于种源3，但强于种源1。不同种源在水分胁迫条件下黎明叶水势分析表明，栓皮栎种源1忍耐土壤含水量阈值为20％左右，种源2、种源3在18％左右，种源4在17％左右。各种源的这几种能力差异是导致它们抗旱性、生长量差异的重要原因。中文摘要3.在自然条件下.不同种源水分平衡参数随物候发育和环境条件变化发生适应性调 整，种源111洋丁差异。栓皮栋d种源水分参数（甲，.、甲，;l卜、wsl）l、￡）随季节 变化，其中种源d季节变化不l刃显，l{lJ种洲!变幅较大:不1司种源在早春展叶后， 各种水分参数表现出水分平衡能力较弱，而这一时期土壤水分含量较低的时期， 是树木生长发育的“生态脆弱期”。，l.通过叶片保水力、渗透调节能力、蒸腾速率、净光合速率、抗氧化保护酶活性和 单.位叶而积于平等7项指标综合分析表明，种源3在适应性和抗一旱生产力方面均 表现较好，种源l在正常条件下速生，抗一旱生i;沈力较龙，种源4有较其它3个种 源更强的耐旱能力，但在水分正常条件下生长较慢。在栓皮栋生产栽培中，应该 根据适地适树的原则，选择优良种源。更多还原

【Abstract】 Using four provenances ( from Bushan ML , Funiushan Mt., the north slope of Qinling Mt. and lluanglong Mt.) of Quercus variabilis as materials, this paper mainly deals with the drought-resistant characters and mechanism of four provenances of Quercus variabilis from the aspects of water physiological ecology, photosynthesis, and protection enzyme system unti-oxidation under field experiment and potted experiment. On the basis of the study on the growth and physiological characteristics, index system on comprehensive judgment of drought-resistance ability of the provenances was suggested and the drought resistance ability of the provenances were judged comprehensively. The main results were as follow: 1.The differences of drought-resistance to water stress of four provenances of Quercus var iabilis mainly due to the result of their long-term adaptation to the environment of their original inhabit. There were stable genetic features in morphological character, physiology and ecology, so it is significantly important to evaluate later-generation. 2.The drought-resistance mechanisms of four provenances were deferent. Under drought stress, provenance 4 has the high specific leaf dry weight, strong ability of leaf water holding, low transpiration ; thick and hard cell wall, high water-maintenance, strong ability of anti-oxidation; under sever drought stress, it has the characters of low productivity and high water use efficiency; provenance 1’s water potential, cellular elasticity, drought-resistance productivity and water use efficiency dropped dramatically, And it closed its stomas early to minimize the loss of water; its ability of cleanup of protection enzyme system lost the balance too soon, leading to the rapidly accumulation of the HA. and high electrolyte leakage. Provenance 3 has the characters of low transpiration, high root/shoot biomass ratio, high turgor maintaining and osmotic adjustment; its ability of cleanup of protection enzyme system is solely inferior to provenance 4 and it has stronger potential drought-resistance; under sever drought stress,it closed its stomas later to maintain photosynthesis rate, and still can accumulate dry materials to some degreed, provenance 2 has low water potential and water-maintains, normal ability of leaf water holding, its ability of adaptation to water stress and drought-resistance productivity was inferior to provenance 3 but stronger than those of provenance 1. the relationship between predawn water potential of four provenances of Quercus variabilis and soil water content indicated the water stress critical numerical value of provenance 1 is 20%, provenance 2 and provenance 3 are 18% , provenance 4 is 17%. the differences above were the main causes of their different response to water stress and growth status.3. Water parameters and drought-tolerance of four provenances have a seasonal change, the reasons of this changes can be found from physiology and structure during the course of the growth and development of trees. During the period of leaves expanding, these Water parameters reflect their ability of drought-tolerance is weaker, while it happen to lower soil water content, so this period can be called the "ecological weak time" .4. The indices adaptability to drought and of productivity to drought were analyzed. The leaf water-losing rate, photosynthesis, transpiration, water use efficiency and protection enzyme system anti-oxidation and the ability of osmotic adjustment were suggested to be used as comprehensive judgment indexes in drought-resistance provenances selection. Provenance 2 and provenance 3 have a better ability of water adaptability and drought-resistance productivity, Provenance 1 has a faster speed of growth under the normal water condition, but its ability to adapt water stress is weaker, Provenance 4 has the strongest ability of drought-resistance, but it has a normal speed of growth. The principle of suitable trees for suitable areas should be considered in the plantation of Quercus variabilis.更多还原