【作者】 赵秀莲；

【导师】 肖文发； 江泽平；

【作者基本信息】 中国林业科学研究院 ， 生态学， 2007， 博士

【摘要】 本文通过查取有关林木抗旱鉴定的文献，总结了当前林木抗旱性鉴定中常用的方法、指标及林木抗旱性的综合评价方法，并对各种方法与指标的优缺点、应用现状、存在的问题和应用前景进行了阐述。由于指标使用频率的高低不仅能反映人们对各种指标的不同认可度，而且还可以暗示该指标的实用性、简便性及有效性，对林木抗旱鉴定常用的指标做统计，对各指标的使用频率做了计算，同时对指标所体现的树木的抗旱途径及指标的应用范围进行了综合比较。同时，为探讨抗旱鉴定指标在不同年龄树木间的表现差异，鉴定年龄因素是否对抗早鉴定指标及抗旱评价结果带来影响，本文选用同一种源1年生、3年生、5年生三个不同年龄的沙地柏为材料，通过控制水分进行胁迫处理，测定了不同年龄沙地柏抗旱生理特性的差异，主要结果如下：通过算得每个指标的使用频率，得到水势的应用频率最高，达到47.22％。按使用频率的大小，所有的指标通过聚类分析可分为五级。沙地柏保水力在不同年龄间存在差异，高年龄的大于低年龄的保水力。膜透性在未受水分胁迫条件下随着年龄的增加逐渐减弱，在不同年龄间已经形成显著差异。水分亏缺在沙地柏三个不同年龄段间差异不显著，并且在水分胁迫后，沙地柏三个年龄间的水分亏缺值差异也不显著。这不同于枝叶保水力及膜透性这两个指标，这说明该指标对年龄的稳定性要高于前两个指标。在水分胁迫条件下，沙地柏各年龄的净光合速率、RuBP羧化酶活性、表观最大量子产额、胞间浓度在气孔导度与蒸腾速率受到土壤水分胁迫的强烈抑制的同时并没有受到限制性的影响，并且水分利用率有大幅度的提高，说明沙地柏气孔开闭调节对土壤水分条件特别敏感，一定程度下的水分胁迫处理对沙地柏的净光合速率影响较小，沙地柏具有相对稳定的光合产物积累速率。加上沙地柏明显的旱生叶片结构，能够减少蒸腾，表明沙地柏是节水型御旱特性的植物，具有典型的耐旱特性。通过测定沙地柏三个不同年龄的气体交换，得出在未受水分胁迫条件下，除RuBP羧化酶活性这一项指标外，沙地柏净光合速率、蒸腾速率、气孔导度、水分利用率、胞间CO₂浓度、RuBP羧化酶活性、表观最大量子产额多项指标在三个不同年龄间差异不显著。在水分胁迫条件下，沙地柏的净光合速率、RuBP羧化酶活性、表观最大量子产额在水分胁迫条件下随年龄的增加而降低，各年龄间出现了显著性的差异，表明干旱胁迫条件下低年龄的沙地柏要比高年龄的沙地柏生长势高，更具有生命力，但是，5年生沙地柏Ci浓度高于1年生与3年生的沙地柏，并且气孔导度、蒸腾速率，随土壤水分含量的降低而下降的幅度最大，表明5年生沙地柏虽然生命活力不如低年龄的1年生与3年生的沙地柏，但是对水分胁迫的敏感的适应能力却强于1年生与3年生的。基于以上研究结果建议在进行抗旱性鉴定时，抗旱鉴定指标的选取要考虑所选取的抗旱指标对材料的年龄的敏感性及稳定性，如果供试材料的年龄不易统一，尤其在对大田中自然生长的树种进行取材鉴定时，最好选取对年龄稳定性高的抗旱性鉴定指标。同时，在应用对年龄敏感的指标时，试验材料的年龄就需要一致。更多还原

【Abstract】 This paper presents a comprehensive review and analyses on identification indexes andmethods of trees drought resistance. The current situation, existent problems and the future ofthe drought-resistance indicators and methods were set forth in the paper. We made astatistical comparison of every drought-resistance indicator and figure out their appliedfrequency because the applied frequency not only can reflect the workers’ approbation tothem but can suggest their practicability, facility and validity. At the same time, severalphysiological characteristics of Juniperus Sabina at three ages were measured in this paper inorder to make out whether the ages of the plants can influence the result of theirdrought-resistance ability. Main results obtained are as following:Plant water potential is used most frequently at present. Its applied frequency reaches47.22%. All drought-resistance indicators of woody plants in common use are classified intofive levels according to their applied frequency.Water-losing rate of Juniperus Sabina is significantly different among seedling ages.Older seedlings have lower water-losing rate than young seedlings. The relative permeabilityof membrane of Juniperus Sabina depresses as the age grows. Significant difference appearsamong these three ages. But there is no significantly difference on RWD whether under thewater stress or not. This shows that RWD is more age-stable than Water-losing rate andrelative permeability of membrane.Results indicate that while the soil water gradient has a significant effect on stomataconductance, transpiration rate, it has no significant influence on the net photosynthesis rate,CO₂ concentration inside the cell, apparent light use efficiency, and the enzyme RuBP.activity of Juniperus Sabina. Net photosynthesis rate don’t respond sensitively to soil watercontent under water stress. This result evidently indicated that Juniperus Sabina has an extrasensitive stomata regulation. In addition to it’s drought-resistance structures in evidence,Juniperus Sabina is a drought tolerance species in nature, and exhibited a saving water-use strategy in a sandy land ecosystem.There is no significant difference on net photosynthesis rate, stomata conductance, CO₂concentration inside the cell, apparent light use efficiency, water-use efficiency andtranspiration rate among 1-year old seedlings, 3-year old seedlings and 5-year old seedlingsof Juniperus Sabina accept the activity of enzyme RuBP when there is no water stress. As theage of the seedlings grows, net photosynthesis rate, activity of enzyme RuBP and apparentlight use efficiency become low under water stress. Significant difference appears amongthese three seeding ages. This indicates that the younger Juniperus Sabina seedlings are morevital than older ones. In contrast, the 5-year old seedlings have higher CO₂ concentrationinside the cell than 3-year old seedlings and 1-year old seedlings. At the same time, the 5-yearold seedlings have the largest changing range on stomata conductance and transpiration rateas the soil water content grows down. This may indicates that while the 3-year old seedlingsand 1-year old seedlings are more vital than the 5-year seedlings, the 5-year old seedlings aremore adaptive than the 3-year old seedlings and 1-year old seedlings.Therefore, we’d better choose the materials at the same age as the test sample when wedo some drought resistance appraisal. Sensitivity and stability of drought resistance appraisalto seedling age must be considered. If the ages of the test sample are different, we’d betterchoose more age-stable drought-resistant indicators.更多还原