Effects Of Acid Rain And Waterlogging After Anthesis On Physiological Characteristic,Yield And Quality In Wheat

Acid rain is one of the main environmental problems in China.It was published in"Report on the State of Environment in China" that in 2013 the national acid rain pollution was stable in the overall point of view but the degree was still serious.Acid rain area was accounted for 10.6%of the land area,the distribution of acid rain areas were mainly concentrated in the South and along the Yangtze river.Winter wheat is planted in middle and lower reaches of Yangtze River,and acid rain is more serious at the period of flowering to maturity filling,so wheat is easier to suffer from the harm of acid rain.At the same time,spring rain is often occurred in South China,the wheat in this area suffers from double stress of acid rain and waterlogging easily.Wheat is an important food crop in China.Its period of flowering to maturity filling is the most vulnerable to adverse,and this period is also the key period to determine the yield and quality of wheat.In this paper,a potted experiment was carried to study the effects of acid rain of different acidity,waterlogging stress and double stress of acid rain and waterlogging on physiological characteristics,yield and quality in wheat,and try to clarify its mechanism from the point of enzyme,microstructure.The main results were as follows:1.The responses to the acid rain of the two wheat cultivars are different.Compared with CK,acid rain increased the cell gap,reduced the pigment content,the photosynthetic rate,the dry weight of above ground of Wennong17.Acid rain of pH4.0 increased the chlorophyll content at the early grain filling stage,the photosynthetic rate,the dry weight of above ground of Yangmai16.Acid rain of pH2.5 increased the cell gap,reduced the pigment content,the dry weight of above ground of Yangmai16.Waterlogging stress and double stress of acid rain and waterlogging all reduced the pigment content,the photosynthetic rate,the dry weight of above ground of the two wheat cultivars.2.The effects of acid rain on nitrogen metabolism and sulfur metabolism of the two wheat cultivars are different.Acid rain reduced the activities of NR and GS in leaves and the activities of GS and GPT in grains of Wennongl7,and increased the activity of endopeptidase at the early grain filling stage but reduced it at the later stage of grain filling.Acid rain increased the activities of NR,GS and Endopeptidase in leaves and the activities of GS and GPT in grains of Yangmai16.Waterlogging stress and double stress of acid rain and waterlogging all reduced the activities of NR and GS in leaves and the activities of GS and GPT in grains of the two wheat cultivars.Waterlogging stress and double stress of acid rain and waterlogging all increased the activity of Endopeptidase at the early grain filling stage but reduced it at the later grain filling stage.Acid rain increased the sulfur accumulation amount of vegetative organs at maturity,and reduced the sulfur accumulation amount,-S-S content and-SH content in grains of Wennong17.Acid rain reduced the sulfur accumulation amount of vegetative organs at maturity,and increased the sulfur accumulation amount,-S-S content and-SH content in grains of Yangmai16.Waterlogging stress and double stress of acid rain and waterlogging all reduced the sulfur accumulation amount,-S-S content and-SH content in grains of the two wheat cultivars.Acid rain reduced the activities of ATPS and OAS-TL in leaves of Wennong17 and increased the activities of ATPS in leaves of Yangmai16.Waterlogging stress and double stress of acid rain and waterlogging all reduced the activities of ATPS,SAT and OAS-TL in leaves of the two wheat cultivars.3.Acid rain and waterlogging had a certain effect on yield and quality of wheat after anthesis.All stresses reduced the yield except acid rain of pH4.0 on Yangmai 16.Acid rain significantly reduced the grain protein and its component contents,glutenin/gliadin ratio and gluten content of Wennong17 and significantly increased the grain protein content and gliadin content of Yangmai16.Waterlogging stress and double stress of acid rain and waterlogging significantly reduced the grain protein and its component contents,glutenin/gliadin ratio and gluten content.Acid rain of pH2.5 delayed the development of B type starch granule of Wennongl7.Waterlogging and double stress of acid rain and waterlogging all delayed the development of B type starch granule,affected the shape of A type starch granule of the two wheat cultivars.Acid rain made abnormal starch granule appeared,and reduced the total starch content,Amylopectin/Amylose ratio,swelling,peak viscosity and B type starch granule content of the two wheat cultivars.Waterlogging stress and double stress of acid rain and waterlogging all reduced Amylopectin/Amylose ratio,swelling and B type starch granule content and increased the pasting temperature of the two wheat cultivars.In summary,acid rain and waterlogging stress had a certain influence on the growth and physiological characteristics of wheat,and eventually caused the different yield and quality.Compared with single stress,the influence of double stress was greater than the same acidity of acid rain stress of single treatment.