Effects Of Different Day And Night Temperature Enhancement After Anthesis On Quality And Physiological Mechanism Of Wheat Under Free Air Controlled Condition

This experiment used heat-resistant Zhenmai5and heat-sensitive Yangmai16as mate rials, adopting free-air temperature enhancement(FATE), by designing different warming d uration (24hours, daytime and nighttime warming) and different extent (1.5and3℃) to simulate the effect of warming climate on the yield, quality, endogenous hormones, c arbon and nitrogen metabolism enzymes during2009to2011in Danyang. The main results were as follows.1. After anthesis open warming resulted in the reduction of wheat grains per spike and grain weight, and lower yields. Among them, the lower degree of the Zhenmai5was not obvious overall. Yangmai16decreased significantly, and presented a regulation that the more warming, the greater reduction of grain number and grain weight per spike. And in lower warming treatment, the effect of reduction is more obvious in day time warming than that in night time warming. On the contrary, in higher warming treatment, the reduction under night time warming is greater than that in day time warming.2. After anthesis open warming had certain impact on wheat grain shape. Under the warming treatment, the length and thickness of Zhengmai5and Yangmai16grains had decreased in different degree. Comparatively, the decrease is more obvious in Yangmai16than that in Zhengmai5. While in most cases they didn’t reach a significant level, which shows it might cause the lower yield by the effect of warming on the wheat grain shape.3. After anthesis open warming increased the crude protein and wet gluten content in wheat grain. The experiments in the two years showed that the crude protein and wet gluten content increased most respectively10.4%and20.5%. It showed basically the same in the two varieties Zhenmai5and Yangmai16. After anthesis open warming reduced wheat grain bulk density and flour yield, lowered crude fat content in the flour, ash content and falling number, but it increased the dry and wet gluten content in flour.4. After anthesis open warming also had some effect on wheat flour protein components to a certain extent, but there were much differences as the varieties and warming situations are quite different. Warming mainly affected the albumin and gluten content in Zhenmai5. Also it increased the gluten content significantly in Yangmai16the increase can be up to51.0%. It showed that the effect of night time warming treatment on protein components is greater. The trends in two years’experiments were basically the same.5. The effect of after anthesis open warming on the starch content in wheat flour and its components was not significant, but it had a certain impact on the RVA characteristics, and the effects varied due to different varieties and warming scenarios. Warming obviously reduced the peak viscosity and breakdown of Yangmai16, decrease17.3%and38.5%respectively. It had the same trend basically for Zhenmai5, but didn’t reach a significant level.6. After anthesis open warming had a certain impact on wheat endogenous hormone, but it had greater differences due to different varieties. After anthesis0-1Od warming significantly increased the LAA content in Yang Mai16, but after anthesis15-20d warming reduced IAA content heavily in Yang Mai16. The two varieties of wheat had the same trend, but Zhenmai5didn’t change obviously. Warming reduced ZR and iPA content in Yangmai16obviously, but increased ABA content. The two varieties had the same trend, but Zhenmai5had less differences.After anthesis open warming also had a certain impact on carbon and nitrogen metabolism enzyme of wheat, but it resulted in huge differences because of the different varieties and warming scenarios.