Drought has a negative effect on plants, whereas a fundamental issue is whether a drought has a stronger impact on seedling growth under high-irradiance or deep-shade conditions. Shade will alleviate, aggravate the negative effects of drought stress, or the drought and shade effect are independent? To data, there has no consistent conclusion. To solve this scientific problem, professor Junhui Wang research group, State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, and professor Jiyue Li, South China Agricultural University, the two research teams worked together to carry out the experiment. The phenotypic plasticity and gas-exchange parameters were determined under six combinations of light (three levels) and water (two levels). The results will be helpful in prediction of growth performance under micro site condition, and provide theoretical basis in planting density control under certain soil moisture condition, and light environment management of catalpa bungei plantations.
Phenotypic plasticity is the phenomenon by which a plant modifies and adjusts its morphology and physiology to obtain necessary resources in different environments and is a conservative resource-utilization strategy. The average value of phenotypic plasticity of light(PIlight=0.47) is higher than that of water(PIwater=0.21). There is significant difference of gas-exchange parameters between moisture and drought treatment under 80% and 50% light intensity, whereas significant difference of net photosynthetic rate, stomatal conductance and transpiration rate is not observed under 30% light intensity. In summary, the negative effect of drought on catalpa bungei depends on the irradiance conditions.
Original article“A morphophysiological analysis of the effects of drought and shade on Catalpa bungei plantlets”was published on the journal of Acta Physiol Plant(doi:10.1007/s11738-017-2380-2). Dr Junwen Wu is the first author, Professor Junhui Wang and Jiyue Li are Corresponding authors. This research was supported by the National Science and Technology support Program during the Twelfth Five-year Plan Period (2012BAD21B03).