Effect of shading on chlorophyll content and chloroplast ultrastructure in leaves of Tulipa gesneriana.

Under shading conditions,growth characteristics of five cultivars of Tulipa gesneiran were observed,and effects of different shading treatments on chlorophyll contents and chloroplast ultrastructure in their leaves were studied.The results showed that the shade resistance of Queen of Night and Oxford was stronger.Under moderate shading,florescence of two cultivars was postponed,but they grew normally.Chlorophyll contents in leaves of two cultivars decreased as shading intensity increased,and chloroplast ultrastructure changed at the same time.When shading intensity was more than 50%,chloroplast ultrastructure in leaves changed obviously,especially in Queen of Night,part chloroplasts showed irregular oblong,grana lamellae numbers of thylakoid reduced and arranged loosely,and stroma lamellae was blurry.While chloroplast ultrastructure of Oxford changed lesser,which meant it had stronger shade resistance than that of Queen of Night.