角质层而非气孔调控木兰科植物叶片最小导度OA

To understand the response and adaptation mechanisms of forest plants to drought,the minimum leaf conductance(gmin)of 26 Magnoliaceae species(16 evergreen and 10 deciduous)in a common garden was measured.The results showed that the gmin of evergreen species[6.5 mmol/(m2ꞏs)]was significantly lower than that of deciduous species[11.6 mmol/(m2ꞏs)],and gmin was generally significantly negatively correlated with leaf cuticle thickness,but not significantly correlated with stomatal size,density,and stomatal index.The gmin decreased with the increase of mean annual temperature(MAT)of the species distribution area,but was not significantly correlated with mean annual precipitation(MAP).However,in evergreen species,the gmin decreased significantly with the decrease of MAP in distribution area,indicating that reducing gmin was an adaptation strategy to drought adopted by evergreen species(but not deciduous species).In addition,evergreen species had thicker cuticles,which explained the lower gmin.There was significant interspecific variability in gmin of Magnoliaceae species,and it was mainly regulated by cuticle characteristics rather than stomatal characteristics.These would provide a new perspective for revealing the drought adaptation mechanisms of plants.