Effects Of CO₂ Concentration?Water Content And Their Interactions On The Growth,Development And Yield-related Traits In Wheat?Triticum Aestivum L.?

IPCC predicts that global temperature will generally rise by 1.5 C,CO2 concentration will rise to 550 ppm and drought will continue in the middle of this century.Wheat is the main food crop in China.How will CO2 concentration and water affect wheat agronomic and Yield-related traits,dry matter accumulation and leaf function in the future high temperature environment? In view of this,the open-top chamber(OTC)was used to simulate the future climate and environmental conditions,and the effects of CO2 concentration,moisture and their interaction on wheat growth,yield and physiological mechanism were studied with different green-holding wheat varieties Hanshun 3 and Yannong 19 as test materials,which provided a basis for wheat production to cope with the future climate and environment and formulate corresponding cultivation and management measures.In addition,yield traits of wheat in future climate and current climate were evaluated.The main results are as follows:(1)Simulation of future climate and environmental conditionsUsing OTC system to simulate future climate scenarios,the simulated CO2 concentration reached 550 ppm in the whole growth period,and the temperature was 1.4 C higher than that in the field.Irrigation treatment was 70-80% of field water holding capacity,and drought treatment was 45-55% of field water holding capacity.(2)Effects of CO2 concentration,water content and their interaction on Agronomic and Yield-related Traits of WheatUnder high temperature in OTC room,agronomic and Yield-related Traits of tobacco cultivar Yannong 19 with high CO2 concentration increased significantly;agronomic and Yield-related Traits of two cultivars decreased significantly under drought treatment;agronomic and Yield-related Traits of two cultivars did not change significantly under high CO2 concentration and drought treatment,while agronomic and Yield-related Traits of two wheat cultivars increased significantly under high CO2 concentration and irrigation treatment.In OTC,high CO2 concentration or drought treatment could advance the maturity of Wheat by 5 days.The maturation period of the two cultivars was 7 days earlier due to the interaction of two factors.It can be concluded that high CO2 concentration and drought accelerated the development of crops and shortened the growth period.From agronomic traits and Yield-related traits,the green-holding variety Yannong 19 is more sensitive to climate change.In addition,strengthening water management will be an important measure for wheat production in the future.(3)Effects of CO2 concentration,water content and their interaction on dry matter accumulation in WheatHigh CO2 concentration significantly increased the dry matter accumulation of the two cultivars in OTC room and significantly decreased the dry matter accumulation of wheat under drought conditions.High CO2 concentration and drought interaction reduced the dry matter accumulation of both cultivars.(4)Effects of CO2 Concentration,Water Content and Interaction on Leaf Function of WheatUnder high temperature in OTC room,high CO2 concentration decreased SPAD,GLAD,Tr,Gs and Y(II)and increased POD activity of two wheat varieties;chlorophyll fluorescence parameters of Yannong 19,a green-holding variety,and SPAD,GLAD,Tr,Gs of two wheat varieties were significantly reduced under drought conditions;SPAD,GLAD,Tr,Gs of two wheat varieties were significantly decreased under high CO2 concentration and drought interaction conditions,while MDA and soluble eggs were significantly decreased.White content increased,but Pn,Ci,chlorophyll fluorescence parameters,SOD and POD activity did not change significantly.(5)Assessment of future and current climatic and environmental conditionsAccording to GGE bioplot analysis,Four simulated environments(No.1 environmental treatment is high temperature+high CO2 concentration+irrigation is abbreviated as WW+HC,No.2 environmental treatment is high temperature+high CO2 concentration+drought is abbreviated as DS+HC,No.3 environmental treatment is high temperature+normal CO2 concentration+irrigation is abbreviated as WW,No.4 environmental treatment is high temperature+normal CO2 concentration+drought is abbreviated as DS)and field irrigation and rainfed two environments are evaluated.It was found that environmental treatment No.1 was the most favorable for wheat yield traits,especially economic yield.