Study On Factors Influcing Color Of Flour And Its Products And QTL Analysis

Wheat is one of the three major food crops in the world, and it is the main food of China. With the improvement of people's living standards, more and more people pay attention to the color of the flour and traditional flour products. Flour color not only affects the sensory quality of flour products, but also affects the popularity degree of the market. To detect genetic locus controlling the color of flour and its products plays an important role in the color improvement in wheat quality breeding.In this study, the correlation analyses and QTL mapping for the color of flour and its products were conducted using RIL population under five environments in four years. The main results are as follows: 1.The relationship between the color of wheat flour and its influencing factorsFlour color brightness(L* value) was negatively related to the yellowness of flour color(b * value) and starch color redness(a* value), and was significantly negatively correlated to protein content, starch color yellowness(b * value), and gluten color redness(a * value), correlation coefficients were-0.233,-0.268,-0.266, respectively. In addition, flour color brightness(L* value) was positively relative with starch color brightness(L* value), and significantly positively correlated with gluten color brightness(L* value). 2. Correlation analysis of color of wheat flour and its productsSteamed bread skin color brightness L* value was extremely correlated with flour color brightness L* value gluten color brightness L* value, and the correlation coefficient was 0.394 and 0.402 respectively,but it was significantly negatively correlated with flour color red degree a* value, starch color red degree a* value, starch color yellow degree b* value, and gluten color red degree a* value, and the correlation coefficient was-0.203,-0.227,-0.342,-0.446, respectively. Bread core color brightness L* value was significantly positively correlated with and flour color brightness L* value and gluten color brightness L* value, and correlation coefficient was 0.328 and 0.426, but with starch color yellow degree b* value, gluten color red degree a* value was extremely significant negative correlation, and correlation coefficients were-0.329 and-0.348. In addition, bread core color brightness L* value was negatively correlated with a* value of starch color. Color score of steamed bread was significantly positive correlated with steamed bread skin color brightness L* value, and steamed bread core color brightness L* value, but it was significantly negatively correlated with steamed skin color yellow b*value, and steamed bread color yellow b* value.Fresh noodle color brightness L* value was highly significant positive correlated with flour color brightness L* value and gluten color brightness L* value, and correlation coefficients were 0.198 and 0.247. Fresh noodle color brightness L* value was significantly positively correlated with starch color brightness L* value, but it was extremely significant negative correlated with the a* value of flour color, starch color yellow degree b* value, gluten color red degree a* value, and correlation coefficients were-0.354,-0.257,-0.332, respectively. Dry pasta color brightness L* values were positively correlated with the yellowness of flour color b* value with correlation coefficients was 0.219, and it was extremely significant negative correlated with flour color red degree a* value with correlation coefficients was-0.232.Bread core color brightness L* value and flour color brightness L* value was significantly positively correlated, and it was positive correlated with b* value of the color yellow degree, a* value of starch color, brightness L* value, and yellow degree b* value, but not significant. In addition, bread core color brightness L* value with the flour color red degree a* value, flour color brightness L* value, starch color yellow degree b* value, gluten color brightness L* value was negatively correlated, but not significant. 3.QTL mapping for the color of flour and flour productsTen QTLs for the color of wheat flour were detected, which located on chromosome 4B, 1A and 7B, and QFA7 B.7-2 with the highest additive effect, explaining the 29.06% of phenotypic variation. Eight QTLs for the color of starch were detected, located on chromosome 1A, 4A, 7A, 1B, 2B, 4B, and QAB2 B.7-69 with the highest contribution rate explaining 9.42% phenotypic variation. Six QTLs for color of gluten were detected, located on 2A, 1B, 4B, 7B, 3D, the highest contribution rate of QGB4 B.4-17 was 22.24%.There were 4 genetic loci for color of wet and dry noodle were detected, which located on chromosome 3B and 4B, QNSA4 B.4-17 with the highest contribution rate, explaining the phenotypic variation was16.43%. 10 loci were detecte on chromosome 1B, 4B, 5B, 7B and 2A for color of steamed bread, of which, QMPA4 B.4-17 explained the 17.35% phenotypic variation. 4 QTLs for the color of bread were detected and mainly located on chromosome 4B and 7B, among which QBPB4 B.5-94 explained the phenotypic contribution rate of 12.06%. 4. Analysis of variance of PPO allelesBecause the PPO activity was greatly influenced by the storage time of the material, in this study, the PPO allele of RIL population was determined, and the variance analysis was performed. The results showed that PPO-Dl alleles were found in two parents and RIL population, 164 RIL lines with PPO-Dla genotype and 23 RIL lines was PPO-Dlb genotype, and there was no significant difference in the color of the flour between different PPO-DlRIL lines genotypes. In addition, 17 lines with PPO-Ala, 155 lines with PPO-Alb, and 11 lines with PPO-Ala and PPO-Alb at the same time. There was a significant level of flour color brightness in the lines with both Ppo-Ala and Ppo-Alb, but the Ppo-Ala lines and Ppo-Alb lines were not significantly related to each other. In the natural population, there were 17 lines containing PPO-Ala and 93 lines containing PPO-Alb, and 17 lines containing PPO-Ala and PPO-Alb. Through the variance analysis, no significant different was found in color. In natural populations, 76 lines contain PPO-Dlb, 95 lines do not contain PPO-Dlb. And the different of flour color brightness also showed no significant level. The variance analysis results showed that the color of two genotypes was n. In natural populations, 76 lines containing PPO-Dlb, 95 lines without PPO-Dlb, and there was no significant level in flour color brightness. 5. Selction of high brightness germplasm resources of wheat flourColor brightness of 205 wheat germplasm resources were determined. The results showed that the variation range of color brightness was 3.34, the average value was 91.66, and the coefficient of variation was 0.63.There were 30 varieties(lines) of flour with high brightness, such as, Wanmai 50, Fanmai 50, Wei 60182. Among them Wanmai 50 possess the highest brightness with 93.26, Ten varieties(lines) flour color brightness was low, such as, Bonong 6, Sheng 46, Shi B07-4056. Bonong 6 was the lowest brightness with 89.83.