Effects of Pigment Indicators on the Color Expression of Leaves of the Colored-leaf Garden Plants

[Objective] In this study, the relationship between the pigments and the color expression of leaves of colored-leaf plants was discussed. [Method] The colors of leaf blades of 6 kinds of plants were analyzed with the Royal Horticultural Soci-ety Colour Chart. The chlorophyl content, carotenoids content and anthocyanin con-tent in leaf blades were determined. In addition, the color types of leaf blades, kinds of pigments, pigment contents and pigment distributions of 6 kinds of plants were compared. [Result] The chlorophyl contents ranked as Populus canadensis Moench （green leaves） 〉 Populus deltoids cv. Zhonghuahongye （purple green leaves） 〉 Populus euramericana cv. Quanhong （red leaves）; Acer palmatum Thunb. （green leaves） 〉 Acer palmatum cv. Atropurpureum （purple red leaves） 〉 Acer pal-matum Thunb. cv. Atropurpureum （red leaves）. The ranking of anthocyanin contents was just opposite. The chlorophyl content was negatively related to the anthocyanin content. The leaf color of plants is determined by various pigments. The more the chlorophyl is, the greener the leaf is. The more the anthocyanin is, the redder the leaf is. In the colored-leaf plants, the chlorophyl content represents about 80% of the content of pigments, the carotenoids content represents about 17%, and the an-thocyanin represents about 3%. There is a difference in the chlorophyl content be-tween colored-leaf plants and green plants. However, the relatively low chlorophyl content wil not hamper the normal life activities of colored-leaf plants. [Conclusion] We hoped to provide reference and basis for the production and landscaping of col-ored-leaf plants.

Investigation and Application of Colored-leaf Plants in Tibet

For the quantitative analysis of colored-leaf plants in Tibet,the five-point sampling method is used for stratified investigation of garden plant communities in Tibet.(i)There are a total of 46 families,76 genera and 110 species of garden colored-leaf plants in Tibet,including 56 kinds of trees,40 kinds of bushes,9 kinds of herbs,4 kinds of vines and 1 kind of bamboo.There are too few colored-leaf herbs and bamboos,and there is a serious imbalance between evergreen and deciduous trees,between coniferous and broad leaved forests.(ii)The most widely applied families include Rosaceae(26),Salicaceae(12),Fabaceae(6),Aceraceae(5),Oleaceae(4)and Elaeagnaceae(4),accounting for 23.64%,10.91%,5.46%,4.55%,3.64% and 3.64% of the investigated colored-leaf plants,respectively.(iii)In terms of color,there are 55 kinds of red plants,43 kinds of yellow plants and 12 kinds of plants with other colors,accounting for 50.00%,39.09%and 10.91% of colored-leaf plants,respectively.There are 9 kinds of spring color leaf plants,63 kinds of autumn color leaf plants,29 kinds of constant color leaf plants,7 kinds of double color leaf plants and 2 kinds of spot color leaf plants,accounting for 8.18%,57.27%,26.36%,6.36% and 1.82% of colored-leaf plants,respectively,indicating that it is dominated by autumn color leaf and constant color leaf plants.(iv)In terms of importance value of trees,the top two are Salix alba(37.623)and Prunus cerasifera f.atropurpurea(26.063); in terms of importance value of bushes,the top three are Ligustrum × vicaryi Hort(22.577),Berberis thunbergii‘atropurpurea Nana'(18.987)and Platycladus orientalis Franco cv.Sieboldii(10.529); in terms of importance value of herbs,the top two are Taraxacum sherriffii(0.915)and Oxalis triangu laris cv.purpurea(0.326).(v)In terms of species abundance of colored-leaf plants,it is in the order of Nyingchi(94)> Lhasa(47)> Qamdo(43)> Shannan(34)> Xigaze(21)> Ali(7)> Nagqu(5).There are great differences between regions: it is highest in Nyingchi while it is lowest in Nagqu.Based on the main problems in the application of colored-leaf plants in Tibet,this paper makes the corresponding recommendations.

Application of Colored-leaf Plants in Landscape Construction

With the gradual improvement of living standard, the public demands on landscaping have focused more on quality than on quantity, and plant furnishing has grown from singular green plants to colored-leaf plants with multiple layers. Confi guration of colored-leaf plants follows certain principles and patterns to enrich the beauty of plant landscaping, construct colorful urban green spaces, satisfy increasing application and aesthetic needs of the public, and reflect value of plant landscaping.

北京城市绿地彩叶植物应用现状及优化策略

彩叶植物以其色彩丰富、观赏期长等特点,在各类城市绿地中备受青睐。文章对北京市28条城市道路、16个居住小区、10所高校和18座公园CLP的应用情况进行实地调查,结果表明,北京城市绿地中CLP涉及67种,隶属于37科47属,但半数以上的CLP应用频度较低(F<20%),CLP的种植搭配形式较为局限,色彩多集中于红、黄两色。公园绿地及高校绿地中CLP的种类和种植搭配形式较为多样,但常用品种多集中于银杏、紫叶李和紫叶小檗;道路绿地中CLP的种类选择及应用形式较为单一;居住绿地中CLP存在一定的应用差异,总体应用状况不佳。说明现阶段北京城市绿地CLP的应用种类不多、常用品种少、种植形式单一、景观品质低。据此,从扩展彩叶植物的新品种应用、加强对现有彩叶植物的应用推广、优化彩叶植物的种植搭配形式、兼顾彩叶植物的时空动态特征4个方面提出优化策略。