Genome-wide Association Analysis And Functional Marker Development Of Peroxidases Activity In Comment Wheat

Flour color is an important indicator of wheat quality.The activity of peroxidase（POD）in wheat grains is an important reason for the browning and bleaching of flour and flour products during processing and storage.Therefore,exploring the characteristics of POD gene has become an important goal of molecular marker-assisted breeding of wheat quality improvement.In this study,Genome-wide association study（GWAS）was used to analyze the POD activity genes of wheat cultivars by using 90 K iSelect chips in151 and 85 wheat cultivars in Yellow & Huai Facultative Winter Wheat Region（YHRVWWR）and Northern China Plain Winter Wheat Region（NWWR）.And clone the POD activity gene of wheat 7D chromosome.According to the sequence difference between allelic variants,the functional markers were developed.The main results are as follows:1.Using the wheat 90 K SNP array,the POD activity of the materials in YHRVWWR and NWWR was carried out.Twenty sites（P < 0.001）were significantly associated with POD activity in YHRVWWR and NWWR,respectively.And each explained 7.8-23.3% of phenotypic variation.The results of regression analysis showed that the POD activity of wheat grain was higher with the increase of the number of excellent alleles.（PMM-D1）,horseradish peroxidase（PER40）and alkyl hydroperoxide reductase（F775₃1640）were identified in this study.The results showed that there were three candidate genes related to POD activity.2.The total length of TaPod-D1 gene was 1124 bp,and the similarity between allelic variation was97.08%.There were 24 SNP loci.Contains a 1083 bp ORF encoding 360 amino acids,and the TaPod-D1 a has 98% similarity to the amino acid residues encoded by the TaPod-D1 b gene.The results of bioinformatics analysis showed that TaPod-D1 a and TaPod-D1 b genes respectively encode transmembrane proteins and non-transmembrane proteins,and two protein predicted signal peptides and secondary structure and phylogenetic tree analysis found that TaPod-D1 a and TaPod-D1 b was difference protein functional.3.A pair of dominant complementary markers POD-7D1 and POD-7D6 were developed based on the TaPod-D1 allele TaPod-D1 a and TaPod-D1 b.POD-7D1 can amplify 540 bp fragment in TaPod-D1 a material,but not in TaPod-D1 b material.In combination with the high POD activity,POD-7D6 could amplify the 640 bp fragment in TaPod-D1 b material,and correlated with the low POD activity,and validated the functional markers by using 233 cultivars in YHRVWWR and NWWR.The results showed that the POD activity of TaPod-D1 b was significantly higher than that of TaPod-D1a（P < 0.05）.Therefore,POD-7D1 and POD-7D6 and POD gene-related,and can be effectively used for genetic improvement of POD activity.