Analysis Of Wheat Starch Quality Genotype And En Vironmental Effects And Study On The Mechanism Of Resistant Starch Formation

As the third largest crop in the world,wheat is also one of the staple foods of Chinese people.The pursuit of its nutritional quality is of great significance to people’s health.Starch is an indispensable carbohydrate for human survival.Among them,resistant starch has superior physiological functions than ordinary starch,and has become a hot research direction of carbohydrates.The purpose of the experiment I(30 wheat varieties were planted in 7locations in Henan province)was to understand the difference in resistant starch content of different wheat varieties and their relationship with other starch quality traits.The experiment II was carried out in the Science and Education Demonstration Park of Henan Agricultural University(Zhengzhou)in 2018-2019.Two strong gluten wheat varieties(Zhengmai 366 and Xinmai 26)and one black wheat variety(Zhouheimai No.1)were selected to study the relationship between resistant starch accumulation characteristics and starch synthesis-related enzyme gene expression during grain filling.Through the analysis of resistant starch accumulation characteristics,screening of resistant starch-related starch synthesis-related enzyme genes,to provide a reference for probing the formation mechanism of wheat resistant starch.This study provides a certain theoretical basis for the selection of high-quality wheat varieties and the selection of cultivation environment and the selection of varieties with high resistant starch content.The main findings are as follows:1.Analysis of Wheat Starch Quality Traits Genes and Environmental Effects and Analysis of the Correlation between Resistant Starch and Other Quality TraitsThrough the analysis of variety,environment,and the interaction effect between variety and environment,the results show that all tested quality traits are affected by environment and genotype,and the environmental effect of most indicators is greater than the genotype effect.Among the 7 locations,the peak viscosity,trough viscosity,final viscosity,and thinning value of the gelatinization characteristics of the Kaifeng point are better than those of other regions;the comprehensive performance of the resistant starch content and starch quality traits in the Kaifeng point and the original Sun points are better than other regions.The resistant starch content of different wheat varieties ranged from 1.47% to 2.28%,with an average of 1.88%.The resistant starch content of varieties such as Saidemai 1,Bainong 4199,and Xuke 316 were higher.Correlation analysis between resistant starch and other starch quality traits showed that the content of resistant starch was significantly positively correlated with amylose content,peak viscosity,trough viscosity,and final viscosity,with correlation coefficients of0.269*,0.545**,and 0.307*,respectively,0.494**.It shows that while increasing the content of resistant starch,the gelatinization properties of starch can also be improved to a certain extent.2.Characteristics of resistant starch accumulation in wheat grainsAnalysis of starch quality of 3 different types of wheat varieties showed that Xinmai 26 had the highest resistant starch content;at the same time,its amylose content,B-type(particle size between 2 and 9.8 μm)starch grain surface area and number distribution percentage highest.The analysis of the grain filling process showed that Xinmai 26 and Zhengmai 366 had a higher increase of resistant starch,65.6% and 50.5%,respectively,indicating that the accumulation of resistant starch may be mainly in the grains.Middle and late grouting.3.Gene expression characteristics of starch synthesis-related enzymes during groutingDuring grain development,the expression of starch synthesis-related enzyme genes(Ta GBSS1,Ta GBSSII,Ta SSI,Ta SSIIa,Ta SSIIIa,Ta SSIV,Ta BEI,Ta BEIIa,Ta BEIIb,Ta AGPL1,Ta AGPL2,Ta AGPS1-a,Ta AGPS1-b,Ta AGPS2)mainly showed four expression patterns.Among them,genes that are highly expressed in the middle and late stages may play an important role in starch accumulation;among them,the high expression of GBSSI and the low expression of SSI,SSIIa,SBEI and SBEIIa of Xinmai 26 in the middle and late stages of grain development may contribute to resistance The accumulation of starch content.