Effects Of Wx Gene On Stratch Related Traits In Wheat

Amylose is an important factor affecting wheat quality,and its synthesis is controlled by three pairs of Wx genes.In order to analyze the effect of Wx gene on amylose content and starch quality,the nearly isogenic lines of six wheat varieties were used to identify the amylose content,other starch traits and agronomic traits in different growth environments,and The effect of Wx gene on these traits and the correlation between starch-related traits were analyzed.The main results were as follows:1.Using three STS markers published at home and abroad,the near isogenic lines of six wheat varieties were tested,and a total of eight Wx gene combinations were obtained,which were homozygous.2.The deletion of Wx gene had a significant effect on the amylose content of wheat,especially the interaction of 3 gene deletion.The content of amylose in all-waxy genotype was the lowest,which was only 2.57%,and there was a very significant difference between all-waxy genotype and other genotypes.Compared with wild type,double-deletion type reduced amylose content by4.03%-6.52%,and single-deletion type reduced amylose content by 4.03%-6.52%.AAbbdd type had the lowest amylose content,followed by AAbbdd type and AAbbdd type.There were significant differences among amylose contents of the three types,and they were significantly lower than that of the single deletion.The effects of double deletion type were consistent under different genetic background.The amylose content of AAbb DD type was significantly lower than that of other singledeletion type,but the difference between AAbb DD type and AAbb DD type was not significant.The amylose content of single deletion was significantly lower than that of the wild type and the parent,and their effects in different genetic background were different.The deletion of Wx-B1 gene had greater effect on amylose content,but the deletion of Wx-D1 and Wx-A1 gene had smaller effect.The effect of the three genes on the content of amylose was Wx-B1>Wx-D1> Wx-A1.3.The deletion of Wx gene had great effect on other quality traits of wheat.The variation range of total starch content of Wx near isogenic lines was small,and the total starch content of all-waxy lines and their parents was the lowest,which was significantly different from that of other genotypes.There was no significant difference between total starch content of double deletion and single deletion,and the deletion of Wx gene had little effect on total starch content.The amylopectin content increased with the increase of the number of Wx gene deletion,but the ratio of amylopectin to amylose decreased.The protein content of all waxy genotype was higher than that of parent and other genotypes,the wet gluten content was lower than that of parent and other genotypes,and the hardness index was higher than that of parent and wild type.The protein content of double-deletion type was significantly higher than that of single-deletion type,and the content of wet gluten and hardness had no obvious change rule.The deletion of Wx-D1 gene increased the content of wet gluten significantly,and the deletion of Wx-A1 gene increased the grain hardness significantly.4.The deletion of Wx gene had great effect on starch gelatinization properties of wheat.All-waxy genotype flour had lower gelatinization temperature and shorter peak time,its peak viscosity,peakvalley viscosity,final viscosity and rebound value were very significantly lower than that of other genotypes and their parents,and its slack value was lower than that of other genotypes and higher than that of background parents.The partial deletion of Wx gene increased the peak viscosity and the loose value,and the deletion of Wx-B1 had the greatest effect on the peak viscosity.With the increase of the number of Wx gene deletions,the final viscosity,rebound value and gelatinization temperature showed a decreasing trend.The deletion of Wx gene could significantly improve the gelatinization characteristics of starch.5.The deletion of Wx gene had some effect on 1000-grain weight,but had no effect on other agronomic traits.The 1000-grain weight of the whole waxy genotype was the smallest,and there were significant differences between that of the other genotypes.6.Correlation analysis showed that total starch content was significantly positively correlated with amylose content and 1000-grain weight,significantly negatively correlated with amylopectin content and protein content,and very significantly negatively correlated with the ratio of amylopectin to amylose.Amylose content was very significantly negatively correlated with amylopectin content,the ratio of amylopectin to amylose and protein content,significantly positively correlated with wet gluten content and 1000-grain weight,very significantly positively correlated with peak-valley viscosity,final viscosity,rebound value,and peak time and gelatinization temperature,and not significantly correlated with peak viscosity and slack value.