Effects Of Shading On The Morphological And Photosynthetic Physiological Characteristics Of 11 Garden Plant Species

With eleven garden plant species(Odontonema strictum, Piper longum L., Oxalis triangu laris cv.Purpurea, Alternanthera dentara 'rainbow', Clerodendrum ugandense Prain, Chlorophytum bichetii, Brugmansia auaveolens Bercht.et Presl., Ardisia squamulosa Persl., Ardisia perreticulata C. Chen, Piper hancei Maxim., Aglaonema 'Pattaya Beauty') under different light shading treatments (100%,58%,33% and 4.8% of sunlight), a research has been carried out into different morphological, physiological and photosynthetic indices, results showed that:1. Accompanied with shading levels increasing, the color of leaf deepened, the leaf length, the leaf width, the leaf area and the plant height increased, but the SLW decreased. When the light condition was moderate, the florescence prolonged and the numbers of flowers increased, if the light condition was too strong or too weak, the number of flowers decreased or had no flowers.2. As the extent of shading increasing, the water content of leaf, the chlorophyll a content, the chlorophyll b content, the chlorophyll a+b content increased, but the chlorophyll a/b ratio, the sugar content, the dark respiration rate and the light compensation point decreased significantly. The maximum value of daily average net photosynthetic and high photosynthetic efficiency appeared under the suitable light condition.3. Shade-tolerance of 11 garden plant species were synthetically estimated by membership function. The shade-tolerance ability of the 11 garden plant species from strong to weak was in following order:Chlorophytum bichetii, Aglaonema 'Pattaya Beauty', Oxalis triangu laris cv.Purpurea, Ardisia squamulosa Persl., Brugmansia auaveolens Bercht.et Presl., Piper hancei Maxim., Odontonema strictum, Ardisia perreticulata C. Chen, Clerodendrum ugandense Prain, Alternanthera dentara 'rainbow' and Piper longum L.4. Based on the observation and the comprehensive analysis, the following species with good shade-tolerance (Chlorophytum bichetii, Aglaonema 'Pattaya Beauty'and Oxalis triangu laris cv.Purpurea) can be widely used as ornamental plants.