Lipoxygenase Activity And Its Genotype And Environment Interactions For Kernels Of Different Wheat Varieties

68wheat varieties （lines） were selected as materials to test the activity oflipoxygenase （LOX）, the content of total pentosan （TP）, water-soluble pentosan （WSP） andwater-insoluble pentosan （WIP）, and make correlation and cluster analysis. Meanwhile, theother ten wheat varieties or lines, including Wanmai48et al, were also selected todeterminate the LOX activity and other12quality traits, and the relationship of LOXactivity with some wheat quality traits were analyzed. They were sown in five locations ofHuainan areas field trial in Anhui Provincial wheat variety regional experiments toinvestigate the effects of genotype and environment on LOX activity of wheat. The LOXactivity was determined spectrophotometrically in106wheat varieties growned in Hefei in2007-2008and2008-2009crop seasons, and the correlation and cluster analysis weremade. We also studied the LOX activity distribution in different population F₂ofLumai22/Yangmai9hybrid seeds.The results showed as follows:1、The difference of LOX activity, the content of TP, WSP and WIP were highlysignificant among the68wheat varieties （lines）. The means of LOX activity, the contentsof WSP, WIP and TP were10.35nkat·g^-1,4.49%,0.90%and3.59%, respectively. Therange of them were4.50nkat·g^-1～19.40nkat·g^-1,2.93%～5.95%,0.49%～1.35%and1.92%～5.01%, respectively. Correlation analysis showed that the LOX activity waspositive related with the content of TP, WSP and WIP, but not significant. Based on longestdistance （Euclidean distance） method, all the varieties could be clustered into4majorgroups.2、Variance analysis of the LOX activity, protein, amylose, RVA parameters and other9quality traits showed that, in addition to pasting temperature, the difference of theremaining12quality traits were highly significant among the10wheat varieties.Correlation analysis showed that the LOX activity of whole mills was high positivelycorrelated with that of flour, high negatively or negatively correlated with the finalviscosity, set back, peak time, amylose contents and low viscosity; LOX activity of flourwas high negatively or negatively correlated with low viscosity, final viscosity, set back,peak time, peak viscosity and amylose contents. The high LOX activity is negative impacton the major quality traits of the whole wheat flour and flour in the grains. Therefore, weshould screen the materials of low LOX activity in the breeding. Utilization of LOX to theimprovement of wheat quality was discussed. 3、10wheat cultivars were sown in five locations of Huainan field trial in AnhuiProvince to investigate the effects of genotype and environment on lipoxygenase activityof wheat. The results showed that， the difference of genotype and environment all hadhighly significant influence on LOX activity. While the genotypic effect played main rolecompared with the environment and genotype×environment interactions.4、The means of LOX activity of106different sources wheat varieties in2008and2009crop seasons, were8.53nkat·g^-1,9.95nkat·g^-1, respectively. The variation of LOXactivity of the experimental varieties in two crop seasons was highly significant and thecoefficients of variation were all more than30.00%, and there were highly significantcorrelation between LOX activity of two crop seasons，indicating that LOX activity iscontrolled by gene. Based on longest distance （Euclidean distance） method, all the varietiescould be clustered into5major groups.5、The means of LOX activity of284F₂plant grains from “Lumai22/Yangmai9” was9.49nkat·g^-1. The range of them were2.12nkat·g^-1～23.85nkat·g^-1.There are24plantsin which the LOX activity was more than high value parent, accounted for8.45%of thetotal numbers;38plants was less than low value parent, accounted for13.38%;14plantswere2.00nkat·g^-1～3.99nkat·g^-1, accounted for4.93%;258plants was4.00nkat·g^-1～19.99nkat·g^-1, accounted for91.84.34%;12plant was20.00nkat·g^-1～23.99nkat·g^-1,accounted for4.23%. In summary, the LOX activity of this F₂population showed apositive skewed distribution.