QTL Mapping For Arabinoxylans Content And Its Relationship With Food Processing Method In Common Wheat

Arabinoxylans (AX) are the major component of the nonstarch polysaccharides present in wheatgrain, and play a critical role in food processing and nutrition quality due to their viscosity in aqueoussolution, hydration and gelation properties. In the present study, two hundreds and fourty recombinantinbred lines (RILs), derived from a cross between PH82-2and Neixiang188, were used to mapquantitative trait loci (QTL) for water-extractable (WE-AX) and total AX (TOT-AX) content, and theirrelationships with major processing quality traits including protein content, Mixograph and RapidViscosity Analyzer (RVA) parameters, and Chinese noodle quality traits were evaluated. Effects ofcultivar, location, flour extraction rate, and food processing method on AX content were evaluated usingfour cultivars grown at two locations. The main results were presented below.1. QTL mapping for AX content and their relationships with major quality traits1) Inclusive composite interval mapping was used to identify five QTL for TOT-AX content onchromosomes1B,4B,5B,5D and6B, accounting for5.6–18.7%of the phenotypic variance,respectively. Five QTL associated with WE-AX content were found on chromosomes1A,1B,5B,6Band7A, explaining4.3–34.9%of the phenotypic variance, respectively. QTL on chromosomes1B,5Band6B for TOT-AX content shared the same marker intervals with those for WE-AX content. QTL forTOT-AX content on chromosomes1B,4B,5B and5D, and for WE-AX content on chromosome6Bwere not reported previously.2)1BL/1RS translocation affected both TOT-AX and WE-AX contents, while grain hardness onlyaffected WE-AX content. Lines with1BL/1RS translocation had higher TOT-AX and WE-AX contentthan those without1BL/1RS translocation. TOT-AX content in hard wheat was significantly higher thanthat in soft wheat. TOT-AX content was significantly correlated with RVA parameters including peakviscosity, breakdown, final viscosity, setback, and Chinese White Salted Noodle quality traits includingspringness and flavor, but the correlation coefficients were influenced by1BL/1RS translocation and thetype of grain hardness.2.Effects of food processing method on AX content1) Sinificant effects of cultivar, location, flour extraction rate and their interactions on WE-AX andTOT-AX content were observed, among which cultivar and flour extraction rate were the major sourcesof variation. WE-AX and TOT-AX content were increased following the increase of flour extraction rate,ranged from0.53%and1.91%for flour with50%extraction rate to0.57%and6.36%for flour with100%extraction rate, respectively. TOT-AX content increased gradually between50%and70%flourextraction rates, but significantly and shaply between70%and90%flour extraction rates, and graduallywhen flour extraction rate beyond90%, while WE-AX content increased gradually among all flourextraction rates.2) WE-AX content was significantly influenced by food processing method including steamed breadand noodles. It increased dramatically to0.69%and0.62%after mixing for steamed bread and noodles, and increased slightly to0.73%and0.70%after fermentation and rest, but decreased dramatically to0.58%and0.55%after steaming and boiling. The increment and decrement for WE-AX content weresignificantly influenced by processing method and flour extraction rate. During processing for steamedbread, the increments of WE-AX content in samples with50%to70%extraction rates were a little bitinfluenced by extraction rate, while significantly influenced by extraction rate for samples with80%to100%extraction rates. The increments of WE-AX content in samples with80%to100%extraction rateswere significantly larger than those in samples with50%to70%extraction rates. These made theWE-AX contents in steamed bread made of samples with50%to70%extraction rates (0.49%,0.52%and0.53%) significantly lower than their counterparts in flours, while those in steamed bread made ofsamples with80%to100%extraction rates (0.61%,0.65%and0.68%) significantly higher than theircounterparts in flours. WE-AX contents in noodles (0.46%–0.55%) were significantly lower than theircounterparts in flours regardless of extraction rates. Processing for steamed bread might be morefavorable for increasing the WE-AX content in the end-use products than that for noodles.