Effects of drought stress and rehydration on physiological and biochemical of four oak species in China

Abstract

Abstract Background Quercus fabri Hance, Quercus serrata Thunb, Quercus acutissima Carruth, and Quercus variabilis BL are four Chinese oak species commonly used for forestation. With the global warming caused by the greenhouse effect, seedlings in mountainous areas after afforestation often suffer seasonal drought stress, which seriously affects their survival and growth. In order to ensure the survival of seedlings, we need to select oak species with strong drought resistance. Therefore, we first need to understand the differences in drought resistance of the four oak tree species at the seedling stage, and comprehensively evaluate their drought resistance capabilities by studying the changes in the physiological and biochemical characteristics of the seedlings under continuous drought and rehydration conditions. Results Compared with the control group, the relative water content, water potential, net photosynthetic rate, transpiration rate, and stomatal conductance levels of the four oaks all showed a downward trend under continuous drought stress, and showed an upward trend after rehydration. The soluble protein, soluble sugar, proline, peroxidase, superoxide dismutase and catalase content of the four oaks increased first and then decreased under drought stress, and then increased after rehydration. The content of glycine betaine and malondialdehyde continued to increase, and gradually decreased after rehydration. Conclusions The weight of each index was calculated by PCA, and then the comprehensive evaluation of each index was carried out through the membership function method. The drought resistance levels of the four oak species were as follows: Q. serrata > Q. fabri > Q. variabilis > Q. acutissima.