Combined Influence Of Atmospheric Warming And Elevated Co2 Concentrations On Potato Physiology And Ecology In The Semi-Arid Region Of The Loess Plateau, China

An experiment was performed to analyse combined influence of atmospheric warming and elevated CO2 concentrations on the physiology, ecology of potato (Solanum tuberosum L.) in the semi-arid region of the Loess Plateau based on parallel observations of meteorological elements. The results showed that precipitation in the experimental region decreased from 1958 to 2016 at a rate of -12.171 mm every 10 years, the air temperature increased substantially during the past 59 years tendency rate based on linear regression was 0.417 degrees C every 10 years, the temperature continued to increase since the 1980s and has been especially substantial since the 2000s. The net photosynthesis rate (Pn) of potato leaves treated with increased temperature (IT) combined with an elevated CO2 concentration (IC) (IT+IC) was improved and was higher than those under the IT and control (CK) treatments during early growth stage. During late growth stage, Pn treated with warming and elevated CO2 concentrations decreased at the highest rate. As the ambient CO2 concentrations increased, leaf stomatal conductance gradually decreased, and stomatal conductance of leaves treated with warming and elevated CO2 concentrations during the growth stage was lower than those of the control leaves. Leaf transpiration rates increased with warming but were highest during the early growth stage; however, during the late growth stage, the transpiration rates of the leaves treated with warming and elevated CO2 concentrations were lower than those of the IT treatment and CK. The water use efficiency of leaves treated with warming and elevated CO2 concentrations distinctly improved and was higher than that of the control and only warming treated leaves. The actual yield of potatoes treated with warming and elevated CO2 concentrations was distinctly higher than that of the control and those treated with only warming. The yield of potatoes treated with only warming was low, and in the semi-arid region of the Loess Plateau, warming was not amenable to the expansion of potato tubers. Warming during the tuber expansion stage delayed tuber growth and caused tuber deformation. Therefore, warming combined with elevated CO2 concentrations is likely to improve the Pn and water use efficiency of potato leaves, promote dry matter accumulation and increase yields. (C) 2020 Friends Science Publishers