Drought Tolerance And Landscape Application Of Ornamental Sweetpotato

The drought tolerance, ornamental characteristics, landscape applications were studied for Ipomoeabatatas(L.)Lam, The results showed that:(1)According to the changes of morphological, physiological and biochemical parameters underdrought stress for four species of Ipomoea batatas, the results showed that: with the drought stressdegree increasing, the length of main vine increment, leaf thickness, leaf relative water content, andchlorophyll content of four sweetpotato cultivars had downward trend, the relative electric conductivity,MDA content, soluble sugar content and free proline content had upward trend, while the SOD activity,POD activity, CAT activity and soluble protein content showed first upward and then downwardtrend.(2)According to the changes of diurnal variation of photosynthesis under drought stress for fourspecies of Ipomoea batatas, the conclusions were drawn that: net photosynthetic rate had the similartrends with transpiration rate and stomatal conductance, while had the opposite trend with intercellularCO2concentration. All varieties net photosynthetic rate and transpiration rate were lower thancomparison, intercellular CO2concentration and stomatal conductance had different trends in differentvarieties.(3)In the basis of classified the drought indices through principal component analysis, droughtresistance of Ipomoea batatas had been evaluated with subordinate function method and weights. Thedrought resistance from high to low were as following: Qiu Bi Te、Zi Gui Ren、Jin Can Can、Bian ErHong.(4)Analytic hierarchy process was used to establish Ipomoea batatas ornamental evaluation model,which included goal level, constraint level, quota level and bottom level. The goal level referred to theintegrated ornament of Ipomoea batatas. The constraint level contained burgeon, leaf, whole plant andstem. The quota level included12indices which reflect the constraint level. The bottom level referred tovarieties which to be evaluated. In the constraint level, leaf had the biggest weight, following wholeplant. In the quota level of leaf, leaf shape and mature leaf color had the biggest weight.(5)According to comprehensive weight of each factor and evaluation standard, multiplied the weight of each factor to obtain the comprehensive score of each cultivars. And21Ipomoea batatasvarieties were classified into4grades, and Qiu Bi Te, Wu Zhi Ju, Zi Gui Ren, Sweet Caroline Bronze，B01-LC1，FD-6，XinXiang and so on had excellent ornamental values, FD-12had a low comprehensiveevaluation which can be eliminate, ornamental value of other varieties were between both of them.(6)According to the characteristics of all varieties，Ipomoea batatas can be applied to gardens inline with the principle of ecological，landscape and people-oriented. The main landscape applicationforms were the edge of flower borders planting，group planting，mass planting，vertical greening，roof greening，rock gardens，the theme parks of sweetpotato and so on.