困难立地对城市观赏植物景观效果的影响机制研究

随着城市化加剧，城市建设用地与绿化用地之间的矛盾日益突出，城市困难立地绿化成为提升城市生态环境质量的必要手段。然而，城市困难立地保水保肥性差，不利于其上植物的生长，进而影响城市观赏植物的景观效果。目前有关城市困难立地研究多集中在修复技术研发等方面，对植物缺乏后续的监测以及机理性探究。本研究拟选择我国城市困难立地常用的观赏植物，通过盆栽模拟困难立地不同水肥条件，并结合野外实际观测，研究困难立地对不同城市观赏植物叶片和花朵景观效果的影响，揭示不同城市观赏植物对困难立地的适应性；分析困难立地对城市观赏植物景观效果产生影响的因素，并基于转录组测序和实时定量PCR技术以及花青素合成关键功能基因分析，阐明城市观赏植物景观效果的影响机制以及植物叶片和花朵呈色变化的分子调控机制；建立困难立地影响城市观赏植物景观效果的主要评价指标，为城市绿化植物的选择、维护管理和景观建设美化效果评价等提供科学依据。

With the intensification of urbanization, the contradiction between urban construction land and greening land is becoming increasingly pronounced. Greening of challenging urban sites is necessary to improve the quality of the urban ecological environment. However, poor water and fertility conditions at challenging urban sites are not conducive to plant growth, impairing the landscape effect of urban ornamental plants. Research to date on challenging urban sites has mainly focused on developing site remediation technology, and there is a lack of follow-up monitoring and mechanical exploration of plants. In the proposed study, commonly used ornamental plants at challenging urban sites in China will be grown in different water and fertilizer conditions in pot cultivation experiments, to determine the influence of challenging site conditions on the landscape effects of leaves and flowers of ornamental plants. Landscape effects will also be examined in the field. The study will reveal the adaptability of different urban ornamental plants to challenging urban sites. This study will analyse the factors that influence the landscape effect of urban ornamental plants at challenging urban sites, and explore the influence mechanism of challenging urban sites on the landscape effect. Based on transcriptome sequencing, real-time quantitative PCR, and analysis of key functional genes for synthesis of anthocyanin, the molecular mechanism regulating leaf and flower color changes in challenged plants will be elucidated. The study will establish main evaluation indices for challenging urban conditions affecting the landscape effect of urban ornamental plants. This will provide a scientific basis for selection, maintenance, and management of urban greening plants and for evaluation of landscaping effects in landscape construction.