COMPARATIVE STUDY ON LEAF ANATOMICAL STRUCTURE AND PHOTOSYNTHETIC CHARACTERISTICS OF WILD AND RETROGRESSION POPULATIONS OF PAPHIOPEDILUM EMERSONII

This study systematically compared the differences in photosynthetic physiological characteristics and leaf anatomical structure between the population of the original habitat and the regression population of Paphiopedilum emersonii.The results showed that the in situ plants showed significant advantages in photosynthetic performance, including higher net photosynthetic rate, maximum photosynthetic rate (Pmax), light saturation point (LSP) and apparent quantum yield (AQY), but their chlorophyll content was lower than that of the regression plants.The anatomical structure showed that the leaves of the regression plants were thicker, and the thickness of palisade tissue and sponge tissue and stomatal area were significantly larger than those of the regression plants, which was positively correlated with their higher chlorophyll content.It is worth noting that photosynthetic parameters (Pmax, LSP, AQY) were significantly positively correlated with pigment parameters (Car/Chl a + b) and upper epidermis thickness (UET).Based on these findings, it is recommended to select a moist habitat with shading when returning to the introduction to alleviate photoinhibition and maintain water balance, thereby increasing the survival rate of the returning plants.