Studies On The Photosynthetic Physiological Characteristics Of Four Colorful Ornamental Plants

The photosynthetic physiological characteristics and abilities of carbon fixing and oxygen releasing of four grafted colorful ornamental plant species, Loropetalum chinense var. rubrum, Prunus persica Atropurpurea, Prunus cerasifera 'Pissardii', Berberis thunbergii var. atropurpurea and their corresponding original seedlings were researched in detail. The results indicated that:(1) There were not obvious differences of photosynthetic rate (Pn), transpiration rate (Tr), stomata conductance (Gs), intercellular carbon dioxide concentration (Ci) between 4 colorful ornamental plant variety trees and their corresponding original seedlings, which indicated the similar physiological characteristics of every couple of trees to some extent in spring, summer and autumn, respectively. But they had the different ecological adaptabilities that were shown though the different values of photosynthetic indexes.(2) All of the Pn, apparent quantum yield (AQY) and the carboxylation efficiency (CE) value of Loropetalum chinense var. rubrum, Prunus persica Atropurpurea and Berberis thunbergii var. atropurpurea were lower than that of the corresponding varieties, which showed that the photosynthetic ability decreased in the three seasons. However, the Pn, AQY and CE value of Prunus cerasifera 'Pissardii' was higher than that of the corresponding variety, which indicated that the photosynthetic ability increased in the three seasons.(3) The every corresponding two varieties had the different responses for intensity of illumination in the three seasons. Loropetalum chinense var. rubrum was more tolerant of shade than Loropetalum chinense, but was not tolerant of strong light in the three seasons. The tolerance of shade and strong light of Prunus persica Atropurpurea was stronger and bad than Prunus persica in spring, respectively. Prunus persica Atropurpurea was not tolerant of shade and strong light in summer, nevertheless being reversed in autumn. Prunus cerasifera 'Pissardii' had the bad tolerance of shade and strong light in spring, but they had the similar tolerance in summer. Prunus cerasifera 'Pissardii' was more tolerant of shade than Prunus salicina and could be adaptable of strong light in autumn. Berberis thunbergii var. atropurpurea had the relatively strong tolerance of shade, but couldn't be tolerance of strong light in spring. And it had the similar adaptability for light in summer and spring, whereas it couldn't endure the shade and strong light in summer.(4) The differences of Pn value between Loropetalum chinense var. rubrum, Prunus cerasifera 'Pissardii', Berberis thunbergii var. atropurpurea and their corresponding varieties were due to the different content of chlorophyll to some extent, whereas being not completely due to the chlorophyll for Prunus persica Atropurpurea and Prunus persica. The content of carotinoid couldn't control the difference of photosynthesis ability. And the anthocyanin couldn't counteract the destroying of strong light.(5) The daily amounts of fixed carbon dioxide and released oxygen of Loropetalum chinense var. rubrum, Prunus persica Atropurpurea, Berberis thunbergii var. atropurpurea were lower than those of their corresponding original seedlings. But the daily amounts of fixed carbon dioxide and released oxygen of Prunus cerasifera 'Pissardii' was higher than that of Prunus salicina.(6) A suggestion of reducing culturing of Loropetalum chinense var. rubrum, Prunus persica Atropurpurea, Berberis thunbergii var. atropurpurea and increasing Prunus cerasifera 'Pissardii' was put forward for increasing the ability of carbon dioxide fixing and oxygen releasing and ecological effect.