【作者】 刘寅；

【导师】 贾黎明；

【作者基本信息】 北京林业大学 ， 森林培育， 2011， 硕士

【摘要】 盐渍土是制约农业生产和人居环境改善的重要因素之一。随着人口迅速增长,经济建设高速发展,开发和利用盐渍化土地,收集耐盐植物资源,掌握植物耐盐生理及耐盐机制已成为科研工作者的重要任务之一。本研究针对天津滨海盐碱地园林绿化植物紧缺的现状,利用实地调查,结合控制实验的方法,筛选出部分滨海盐碱地区耐盐植物,并对可应用于生产实践的植物耐盐性评价指标进行了研究,为丰富滨海地区绿化植物资源和改善生态环境奠定了基础。主要结论如下：1、天津大港水库周边地区土壤含盐量较高,人为干预较少,耐盐植物资源丰富。据调查,该区域有主要植物56种,隶属25科,其中最多的是禾本科、藜科,其次是豆科、蔷薇科、菊科等。特耐盐植物占统计的23.2%,有柽柳、罗布麻等,强耐盐植物占统计的16.1%,有白蜡、地肤等。该区域耐盐植物资源草本种类占绝对优势,木本种类较少,但柽柳、白蜡群落分布面积较大,野生和乡土耐盐植物资源较丰富,如盐地碱蓬、芦苇和白蜡、枣等,分布广泛。2、选择11种天津滨海盐碱地常用绿化植物,进行不同浓度NaCl(0%、0.2%、0.4%、0.6%)胁迫盆栽试验,对形态、生理生化指标进行综合测定,其中龙柏(Sabina chinensis cv. Kaizuka)为特耐盐植物；黄杨(Buxus sinica)、朝鲜黄杨(Buxus microphylla var.koreana)、福禄考(Phlox drummondii)为强耐盐植物；红王子锦带(Weigela florida cv. Red Prince)、矮牵牛(Petun ia hybrida)、金叶女贞(Ligustrum vicaryi)、金叶莸(Caryopteris clandonensis)、丁香(Syzygium aromaticum)为中度耐盐植物；小叶女贞(Ligustrum quihoui)、107杨(Pinus xeuramericana cv.’74/76’)为轻度耐盐或不耐盐植物。3、盐胁迫过程中,苗木存活率、叶片盐害指数、相对生长量、生物量、含水量、细胞膜透性、丙二醛、脯氨酸、细胞内Na+K+Ca2+Mg2+的选择性吸收和运输等多个形态生理指标均随盐胁迫浓度增加和胁迫时间延长而发生变化,各个指标共同作用,综合反映品种耐盐性的强弱。叶片盐害指数随盐胁迫浓度的增加和胁迫时间的延长而增大,苗高相对增长量、总生物量、根、茎、叶鲜、干重随着NaCl浓度的增大都呈下降的趋势,在0.6%NaCl浓度胁迫下,小叶女贞、107杨植株含水量分别较对照下降19.82%和13.90%,而龙柏、朝鲜黄杨仅下降7.18%和7.73%,能维持较高的含水量,表现出较强的抗盐能力。叶片细胞膜相对透性随处理浓度的增大表现出逐渐上升的趋势,脯氨酸含量随胁迫浓度增加而逐渐增加,细胞膜透性和脯氨酸含量随盐胁迫浓度的变化均达到显著和极显著水平。丙二醛含量并不呈单一的变化趋势。植物体根、茎、叶内Na+总含量均随盐处理浓度的增大而增多。组织内K+含量随盐处理浓度的增大而减少。Ca2+含量在不同树种组织内的变化趋势不同,较耐盐树种组织内含量基本保持不变,耐盐性较差的树种,随盐胁迫浓度的增加而下降。盐胁迫对组织中Mg2+含量的影响较小,其变化趋势与Ca2+基本一致。总体上,植物生长和生理各项指标均随盐胁迫浓度增加和胁迫时间延长而发生变化,但这种变化在树种对盐胁迫的忍受范围内比较缓慢,超出临界点,变化比较剧烈,这种变化的幅度与树种的特性以及对胁迫的适应范围有关。脯氨酸对细胞膜具有较强的保护作用,能够减轻盐害,保证植物的生长,但不能有效消除丙二醛对细胞的伤害。4、单靠一个性状或一项指标的测定结果,难以准确反映品种耐盐性的强弱,必须对多个响应性状进行测评,以此综合评价品种耐盐性才更准确可靠。各个指标关联并协同发生变化,各因素在盐害中所起的作用和重要性不同。综合来看,叶片盐害指数、细胞膜透性、脯氨酸含量三个指标最能反映植物受胁迫程度和耐盐性强弱。在生产实践中,简单的进行耐盐性比较测定时,我们更倾向于使用可以观测的形态指标,在生理指标中,则可选择稳定性好、方便易测的细胞膜透性。本研究成果可为天津滨海地区绿化提供几种适生园林植物,为耐盐树种选择和树种耐盐性评价筛选合理的指标提供理论依据和技术支持。更多还原

【Abstract】 Saline soil is one of the important factors in restricting agricultural production and improving living environment. With rapid growth of the population and the high-speed development of economic construction, exploitation and utilization of saline soil, collecting salt-tolerant plants resources and mastering the plant salt resistance physiology and mechanism has become one of the important tasks of researchers.Considering the shortage of tree species for landscaping on the Tianjin coastal saline-alkaline land, I used the method of field investigation and control experiment to select some salt-tolerant plants for the coastal area. And indexes of salinity tolerance assessment applying to production practice were studied,in order to enrich green plant resources in the coastal area and improve the ecological environment.The main results are as follows.1、Beacause of higher soil salinity and less human intervention,the plant species were rich in the investigation site in Tianjin Tanggu Area Dagang reservoir,with the total species of 56 under 25 families. Graminceae and Chenopodiaceae families are the important constructive and dominant species of Saline soil, followed by Leguminosae, Rosaceae and Compositae. Special salt-tolerant plants included Tamarix chinensis, Apocynum venetum and so on, about 23.2% of total. Strong salt-tolerant plants indluded Fraxinus chinensis, Kochia scoparia and so on, about 16.1% of total. There were the largest number of Grass communities and a few Woody community, but distribution of pewter and tamarix community was large. In addition,the region was rich in wild and local salt-tolerant plant resources,for example Suaeda salsa、Phragmites communis、Fraxinus chinensis、Ziziphus jujube and so on.2、Based on the vegetation investigation of the coastal saline-alkaline soils in Tianjin Tanggu Area Dagang reservoir,combined with common greening plants in Tianjin, The 11 tree species grown in pots have been studied on the growth,morphological,physiological and biochemical characters under different concentration NaCl stress. Through measuring the indexes of salt resistant capacity, it was concluded that Sabina chinensis cv. Kaizuka was special salt-tolerant plant, Buxus sinica, Buxus microphylla var.koreana and Phlox drummondii were strong salt-tolerant plants, Weigela florida cv. Red Prince, Petunia hybrida, Ligustrum vicaryi, Caryopteris clandonensis and Syzygium aromaticum were moderate salt-tolerant plants, Ligustrum quihoui and Pinus×euramericana cv.’74/76’ were mild or no salt-tolerant plants.3、Indicators such as the survival capability,the symptoms of the leaves,the height,the biomass, the moisture content,the content of Pro and MDA,the content and the selective transportation of Na+、K+ Ca2+、Mg2+ were changing during the different stress period and the stress symptoms. A combination of growth rate and physiology indexes could be used for reflection of tree species salt-tolerant.The salt damage index of leaves of 11 tree species rise, at the same time, the height, the biomass and water content were inhibited and the difference among NaCl concentration were more significant with the stress time. Under 0.6% NaCl stress, the Moisture Content of Ligustrum quihoui and Pinus×euramericana cv.’74/76’ reduced 19.82% and 13.90% over that of control in the experiment, however, Sabina chinensis cv. Kaizuka and Buxus sinica reduced only 7.18% and 7.73%. They two showed strong containing salt ability.The electrolyte leakage and the content of Pro increased and the difference was significant.To most tree species, the trends of the content of MDA were not obvious. Na+ content increased under the stress of NaCl in most species within the organization. The changing trends of K+ content was opposite to Na+.Ca2+ content was difference among these species, bsically unchanged in salt tolerance plants while decreased in salt-sensitive plants,the same as Mg2+ content. However,there were differences among the species in response time and concentration.The indexes changed slowly in salt stress endure range,but change was dramatic beyond the critical point.The differences had to do with Species characteristic and stress tolerance range.Pro could protect the cell membrane and reduce the damage of salt,and therefore insure plant growth. Nevertheless, Pro could not disarm injury from MDA to cells.4、It was difficult to accurately reflect the strength of salt resistance only on one single character or an index of analytical results. It was necessary to use multiple indices in evaluating salt tolerance so that the result had veracity and reliability.Each factors in salt stress played the different part and importance. On the whole, three analytical indices could mostly reflect salt tolerent which included the salt damage of leaves, the electrolyte leakage and the content of Pro.If only simply to determine or compare salt tolerent among plants in production practice, we tend to use the morphological indexes which could be observed easily.meanwhile the electrolyte leakage as a physiological target was choosed because of steadiness and easy measure.The results not only afforded several suitable landscape plants for the coastal areas, but also help to provide the theoretical and technical support for selection of salt-tolerant tree species and evaluation indexes.更多还原