【作者】 田娜；

【导师】 江海东；

【作者基本信息】 南京农业大学 ， 园艺植物与观赏园艺， 2009， 硕士

【摘要】 屋顶绿化不仅可以使城市大量的屋顶空间得到合理的开发利用,从而极大地拓展城市绿化空间,缓解城市用地紧张的矛盾；同时,其对于保护、改善城市生态环境等方面亦具有巨大的生态价值。本文以南京地区垂盆草乡土品种为试验材料,研究了氮素对垂盆草屋顶草坪冬前及返青后的生长及生理代谢方面的影响,水分对垂盆草屋顶草坪生长和生理特性的影响,保水剂对垂盆草建植和生理代谢的影响；为屋顶绿化的建坪、后期管理提供科学依据和技术支持。研究结果表明：1与对照相比,经过氮素处理后,垂盆草的叶绿素、类胡萝卜素、可溶性糖、可溶性蛋白及脯氨酸的含量有所提高,而细胞膜透性下降,说明施用氮素有助于提高垂盆草冬前生长能力,同时对延迟枯黄、提前返青及延长绿期效果明显,其中处理为5-10gN／m2之间,效果最好。2高施肥量下5-10 g N／m2处理间可以使垂盆草的新生芽数、枝条数、枝条存活率及植株生长高度增加,对植株总干重、地上部干重也有明显促进作用,花期延长,提高综合质量；但是对过高的氮素10g N／m2用量下又会对地下部干重和根冠比有抑制作用。综合实验结果表明：5 g N／m2处理下,在草坪返青后生长、高度、色泽等方面的情况表现最佳,综合质量比较高,同时花期较长,观赏效果较好。3基质相对含水量为45%时,适宜于垂盆草草坪管理期的生长,最大枝条较长,叶片较宽,枝条数较多,细胞膜透性、脯氨酸含量较低,可溶性蛋白、可溶性糖含量较高,单株产量、地上部干重、地下部干重、根冠比值较高,经济和生物水分利用率较高,叶绿素、类胡萝卜素含量及肉质化程度相对较高,外观综合质量表现也比较好。因此,45%的基质相对含水量可以作为垂盆草屋顶草坪水分管理的指标。在降雨条件下垂盆草可以正常生长,说明它本身耐粗放管理,比较适合进行屋顶绿化种植。4在基质中添加保水剂能促进垂盆草新生芽的萌发和伸长,提高光合色素含量、叶片相对含水量、游离氨基酸含量和根系活力,有利于干物质的积累。在干旱处理后,除去0.5g／L处理水平,保水剂对促进植物干物质的积累、地上部的生长以及提高叶片相对含水量、游离氨基酸含量的作用更明显,说明在一定的使用量范围内,保水剂的应用可以缓解水分胁迫对植物造成的不良影响,为植物正常生长提供一定程度保障。但过高的用量反而会降低根系活力,带来负面影响。无论是干旱处理前,还是干旱处理后,施用保水剂后,垂盆草的根冠比与对照相比有所降低。根据综合表现结合经济因素考虑,1g／L的保水剂用量是垂盆草草坪较适宜的用量。更多还原

【Abstract】 Roof garden not only exploits and utilizes lots of roof space, expands the urban green space greatly so as to alleviate urban heat island effects, but also have great ecological value on protection and improvement of urban ecological environment. Taking Sedum sarmentosum as samples, effects of nitrogen fertilizer on the the green period, growth, blossom and turf characteristic of roof turf of Sedum sarmentosum, effects of different relative moisture contents in organic substrate on the growth, physiological characteristics and water use efficiency of Sedum sarmentosum planted on roof, and effects of water retaining agent(WRA) on the growth and physiological metabolism of Sedum sarmentosum were studied in this paper. This could provide scientific basis for the establishment and management of roof turf. The results were as follows:1. Compared to the control, the content of chlorophyll, carotenoid, soluble sugar, soluble protein and proline increased while the leakage of electrolyte induced at the treatment of nitrogen fertilizer, which meant that nitrogen could improve the growth of Sedum sarmentosum before winter. And also nitrogen fertilizer had significant effect on delaying the date of wilting and advancing the date of greenup so as to prolong green period.5-10 g N/m2 treament gave the best performance.2. The number of new shoots and branches, survival rate of new shoots and plant height increased under higher fertilizer treatment of 5-10 g N/m2. At the same time, the total dry weight, the aboveground dry weight and the turf characteristic were improved. Florescence was prolonged as well. But too heavy nitrogen rate (10 g N/m2) limited the underground dry weight and root-shoot ratio. The comprehensive result showed that fertilizer treatment of 5 g N/m2 was the best for the roof turf of Sedum sarmentosum.3.45% relative moisture content of substrate was suitable for the growth of Sedum sarmentosum during management; as well as the content of soluble protein, soluble sugar, dry weight, root shoot ratio, water use efficiency, chlorophyll, carotenoid, and succulence extent were higher, while the leakage of electrolyte and proline content were lower during the two treatments.45% moisture content of organic substrate could be used as a favorable quantitative index for the water management of Sedum sarmentosum turf. Under normal rainfall condition, Sedum sarmentosum can grow well, which indicated that it is suitable for extensive management and and roof garden.4. The effects of water retaining agent(WRA) on the growth and physiological metabolism of Sedum sarmentosum were studied in this paper. WRA was added to the substrate made from vermiculite, peat, coal ash with the same volume. The results showed that the application of WRA promoted the bud germination and elongation, increased the contents of photosynthetic pigments, the leaf relative water content, the free amino acid contents, the root vigor, and dry matter accumulation. Except the dosage of lg/L, WRA had more significant effects on increasing the accumulation of dry matter, the growth of over-ground part, the leaf relative water content, and the amino acid contents under drought condition. But overhigh dosage would reduced the root vigor. The suitable amount of WRA used in the roof turf of Sedum sarmentosum was 1g/L.更多还原