Study On Physiological Characteristics Of Yield Gap Of Different Wheat Varieties Under High Yield Condition

The experiment was conducted from 2016 to 2017 in Shiwang Village,Yanzhou,Shandong Province.Three wheat varieties-Yannong1212,Jimai22 and Liangxing99 were selected as the materials to study the differences in water consumption characteristics,photosynthetic characteristics,nitrogen accumulation and distribution,senescence of flag leaf and root activity for providing theoretical basis for high yield cultivation.The main results were showed as follows:1 Differences in water consumption characteristics of different wheat varietiesThe soil water consumption amount of Yannong1212 was significantly higher than Jimai22 and Liangxing99 from jointing to anthesis and anthesis to maturity.The soil water consumption amount in 40¹60cm of Yannong1212 was significantly higher than Jimai22 and Liangxing99 from jointing to anthesis and anthesis to maturity.The water consumption amount,daily water consumption amount and consumption percentage was Yannong1212>Jimai22>Liangxing99 during anthesis to maturity.2 Differences of photosynthetic characteristics,dry matter accumulation and distribution of different wheat varietiesThe net photosynthetic rate and stomatal conductance in the flag leaf showed Yannong1212>Jimai22>Liangxing99 in 14³5 days after anthesis.The relative chlorophyll content showed Yannong1212>Jimai22>Liangxing99 in 21³5 days after anthesis.The transpiration rate,leaf area index and interception rate of photosynthetic active radiation showed Yannong1212>Jimai22>Liangxing99 at 28³5 days after anthesis.The electron transport rate of flag leaf was Yannong1212>Jimai22>Liangxing99 at14³5 days after anthesis.The photochemical quenching of flag leaf showed Yannong1212>Jimai22>Liangxing99 at 21³5 days after anthesis.The maximum photochemical efficiency and the actual photochemical efficiency of flag leaf showed Yannong1212>Jimai22>Liangxing99 at 28³5 days after anthesis.The dry matter accumulation showed Yannong1212>Jimai22>Liangxing99 at booting and 0,12 and 24 days after anthesis.The amount of dry matter accumulation in grains and the contribution of dry matter to grain after anthesis showed Yannong1212>Jimai22>Liangxing99.3 Differences in plant nitrogen accumulation and distribution and nitrate nitrogen transport in different wheat varietiesThe plant nitrogen accumulation showed Yannong1212>Jimai22>Liangxing99 at anthesis and maturity.At maturity,the accumulation of nitrogen in grains showed Yannong1212>Jimai22>Liangxing99.Nitrogen translocation in vegetative organs showed Yannong1212>Jimai22>Liangxing99.There was no significant difference in the nitrogen accumulation and its contribution to grain after anthesis between Yannong1212 and Jimai22,which were significantly higher than Liangxing99.At mature stage,there was no significant difference in soil NO₃-N content between 0⁴0cm soil layer between Jimai22 and Liangxing99,which was significantly higher than Yannong1212.The soil NO₃-N content between 40¹60cm soil layer showed Liangxing99>Jimai22>Yannong1212.4 Differences in flag leaf senescence and root activity of different wheat varietiesThe superoxide dismutase activity between flag leaves showed Yannong1212>Jimai22>Liangxing99 at 28³5 days after anthesis.At 28³5 days after anthesis,the content of malondialdehyde content of flag leaf showed Liangxing99>Jimai22>Yannong1212.After21³5 days after anthesis,the soluble protein content of flag leaf showed Liangxing99>Jimai22>Yannong1212.The root activity at 12,24 days after anthesis showed Yannong1212>Jimai22>Liangxing99.5 Differences in grain yield and its components,water use efficiency and partial productivity of applied nitrogen of different wheat varietiesThere was no significant difference in spike number between three varieties and the grain number per spike showed Yannong1212>Jimai22>Liangxing99.There no significant difference in 1000^grain weight between Yannong1212 and Jimai22,which was significantly higher than Liangxing99.The grain yield,water use efficiency and partial productivity of applied nitrogen showed Yannong 1212>Jimai 22>Liangxing 99.