Analysis On Major Quality Effects And Identification Of Elite Alleles Of Lipoxygenase In Wheat Grain

In this study,88 wheat cultivars were used to test the seed storage characteristics by artificial accelerated aging,flour color and dough sheet lightness,and the LOX activity,as well as the correlation among them were analyzed to make sure the quality effects of lipoxygenase(Lox)activity in wheat grain.On this base,124 wheat germplasm resources were collected to determine the Lox activity in three years and identify the correlation between lox activity and SSR marker sites which are covering the whole genome,and elite allelic variation for high or low LOX activity.1.The correlation showed that there was no significant correlation between Lox activity of grain and germination rate but a significant negative correlation between Lox activity and germination rate of aged seeds which were conducted to artificially age in 9 days,while there was a significant positive correlation between Lox activity and aging index in 9 days.These results Lox activity of wheat grain had a significant impact on storage characteristics of wheat,the higher Lox activity in grain,the lower storage quality of seeds and the less storability of seeds.2.The Lox activity of wheat grain was positively correlated with flour yellowness(b *)and negatively correlated with flour brightness(L * *)and whiteness(W * *).This indicated that the high Lox activity in wheat grain could iecrease the flour yellowness,but reduce the brightness and whiteness.The very significant negative correlation between Lox activity and dough sheet lightness in 0.5h and 24 h showed that,with the increase of Lox activity in wheat grain,the lightness stability of dough sheet was worse.3.By correlation analysis,17 SSR molecular marker sites were identified to significantly associate with Lox activity among which there 3 markers were on chromosomes 7A and 7B,and 2 markers on chromosomes 1B and 3B,especially XMAG 2944 on chromosome 4D was associated in two years.In addition,the results of phenotype effect of allelic variation showed that 210 bp allelic variation sites of BARC174,205 bp allelic variation sites of BARC 327 and 310 bp variation sites of BARC 60 could be considered as elite allelic variations related to low Lox activity.350 bp allelic variation of BARC 139 and 220 bp allelic variation of BARC488 were related to high lox activity.