Research On Drought-tolerance Of Ornamental Grasses And Its Application In Landscape

Ornamental grasses, as excellent additions to different environments of urban green spaces, have various species, combining with their unique shapes, foliage colors, inflorescences, easy propagation and maintenance. Being water-saving, diversified, artistic and ecological urban landscape, the systematic researches on drought tolerance and landscape uses of ornamental grasses will indicate the academic significance and practical value. The main results were summarized as follow:1. Based on the difference of concepts between ornamental grass and turf grass, the definition of ornamental grass were discussed. The classification, planting and maintenance, reseach status of ornamental grasses were introduced.2. With the typical application examples of ornamental grasses in foreign gardens, the application history of ornamental grasses aboard was summarized as three stages. The poetic-sounding flowery mead in the 16^th and 17^th ceturies was thinked as the original application of ornamental grasses. The landscaping application stage was from the late 1800s to the early 1900s, with several dozen grasses were considered fine subjects for traditional borders and transitional areas of the gradens. Ornamental grasses truly came into their own in the second half of the 20^th century, which was considered as widely application stage.3. According to the study on changes of shape and physiological in four species of ornamental grasses under drought stress, some theoretical foundation for selecting and breeding of drought-tolerant ornamental grasses resources are put forward. The result of the drought-tolerant experiment in summer showed that the increase of the percentage of withered leaves, content of free proline and REC appeared dramatically from the 10^th day, respectively. There were significant positive correlations between the percentage of withered leaves and physiological indexes in Soft rush and Zebra grass under the drought stress. It was indicated that the drought tolerance of Soft rush was better than Zebra grass, based on the analysis of growth appearance and physiological characteristics. The result of the drought-tolerant experiment in autumn showed that the proline content, REC and MDA content increased continuously along with the drought treatments in Fountain grass, Zebra grass and Pampus grass, and it showed obviously positive correlation with the increasing of percentage of withered leaves. The SOD activities in Zebra grass and Fountain grass were remarkable higher than Pampus grass in later stage of drought treatment. According to the morphological and physiological analysis, the drought tolerance decreased in following order: Fountain grass > Zebra grass >Pampus grass.4. Having been investigating ornamental grasses in Hangzhou landscape area for more than one year, 44 species of ornamental grasses were concluded. The application modes of ornamental grasses were singularity. Application frequency of traditional or autochthonous species was higher than others in Hangzhou landscape area, such as Cortaderia selloana, Acorus calamus, Arundo donax and Juncus effuses et al, and the distribution and quantity of ornamental grasses were more concentrated in newly-built scenic spots. Besides, the phenophases of ornamental grasses in Hangzhou westlake scenic spot were put forward.5. Based on the principles of landscape ecology, the application and planting design of ornamental grasses in flower border, ground covers, slope greening, waterside, and rock garden were analyzed. The status for landscape use of ornamental grasses in Shanghai, Hangzhou was analyzed as well. It will be theoretical benefit to the extended apply for ornamental grasses in landscape.