The Introduction Evaluation And Application Of Dahlia Flower In Suzhou City

These indicators are far more than the national average in Suzhou prefecture,including the green space,green area of built-up area,park number and per capita park area.However,a large number of evergreen trees and shrubs are used in plant configuration,herbs used less,lack of species diversity.Therefore,it is of great significance that enrich the species of herbaceous plants to improve the landscape of Suzhou urban greening.In order to investigate the feasibility of dahlia application in Suzhou landscaping,88 Dahlia cultivars were introducted from Gansu Lintao country（fllowed by NO.SD01-SD88）and used to open filed cultivation test.Based on the investigation of biological characteristics,the Dahlia AHP evaluation model have been constructed,the dahlia breeding and cultivation technology have been researched,and the Dahlia application forms in Suzhou urban greening have been discussed.The results are as follow:1.Taking the introduction of dahlia cultivar（SD01-SD76）roots as tested materials,culturing in the open after root propagation,The phenophase,ornamental and adaptability of different dahlia cultivars have been investigation and analysis.The results show that the emergence period of dahlia cultivars from March 10th to 31st,spring flowering from May 29th to July 6th,autumn flowing from October 1st to December 17th（Frost Day）,But there were significant differences among different varieties,76 the tested varieties in the open can grow normally in Suzhou area,of which72 species can complete the entire life history,and exhibit certain ornamental value;The phenological period has great influence on ornamental value,the first flower blooming period of late flowering varieties is approaching Suzhou summer high temperature period,has signficant effect on its growth and development,resulting in a sharp decline in flowing,even not blossom.Compared with early flowering,the view time of late flowering varieties was significantly shortened,the application value in Suzhou urban greening is low.2.With the introduction of dahlia cultivar（SD01-SD76）as research object,22apraisal indexes were selected based on the investigation of biological characteristics.According to the weights of all evaluation indexes,formulate the relevant standard for evaluation,and suitable for Dahlia AHP（Analytic Hierarchy Process,AHP）comprehensive evaluation model was built.A comprehensive evaluation of each variety was carried out by the Dahlia AHP evaluation model.The results showed that 8varieties were rated as grade I,respectively SD05,SD06,SD08,SD14,SD17,SD21,SD31.As the most suitable for the introduction of good varieties in Suzhou.54 varieties were rated as grade II,it is also worthy to imported.10 varieties were rated as grade III,4 varieties were rated as grade IV,it can be concluded that these varieties should be defer introduced or not introduced in Suzhou.3.In order to establish efficient breeding technology of dahlia,With the introduction of Dahlia cultivars（SD77-SD88）as the test materials,the effects of hormone treatment,different varieties,cutting substrates and ear shape on rooting of cuttings were studied.The results show that the rooting effect is different among different Dahlia Cultivars.In spring,the rooting effect was better with solid cuttings,50mg/L NAA dipping treatment 120s,cutting in nutrient soil+perlite（1:1）or nutrient soil matrix.The introduction of Dahlia pinnata root into upland and lowland storage,and set different covering depth.The results show that both the highland or lowland Dahlia tubers stored,buried deep,the coming year has a high germination rate in Suzhou area.But high storage,and the buried depth of more than 10cm is better.4.In order to reduce the adverse effects of the rainy season,strong winds and high temperature climate characteristics in Suzhou area,Dahlia flower cultivation technology is optimized.Taking the dahlia cultivars（SD77-SD86）as tested materials.The dwarfing effect of open dahlia foliage spraying PP₃₃₃,S3307 and CCC were discussed.Results showed that the plant height showed a certain degree of dwarfing after spraying PP₃₃₃and S3307,the average dwarfing rates of different varieties were 16.20%-58.17%,29.03%-79.03%.However,the plant height of different varieties showed two kinds of phenomenon after spraying CCC,including dwarfing and promoting growth,and the top leaves became yellow.Different dwarfing rate indicates that different Dahlia cultivars have different sensitivity to the plant growth retardants.In general,S3307dwarf effect is best,PP₃₃₃ times,CCC effect is the worst.The dwarfing cultivation test as the same time,the effects of plant growth retardants and different cutting degree on dahlia flowering were discussed.The results showed that spraying S3307 and PP₃₃₃ could delay flowering,however,spraying CCC could promote flowering,but the number of days delayed or promoted flowering varied according to the varieties.The results of cutting experiment showed that no cutting plants were about 10d earlier than the top cutting plants,the depth cutting had the greatest influence on flowering time,the flowering period was delayed by 30d.5.Based on analyzing the introduction of dahlia biological characteristics,Suzhou City climate characteristics,urban road condition and open filed cultivation meansures,By the roadside greenbelt and divide the car belt as an example,the configuration mode that dahlia application in Suzhou urban road greening is discussed.