Jichun Tian

Detection of quantitative trait loci for heading date based on the doubled haploid progeny of two elite Chinese wheat cultivars

Quantitative trait loci (QTLs) with epistatic and QTL × environment (QE) interaction for heading date were studied using a doubled haploid (DH) population containing 168 progeny lines derived from a cross between two elite Chinese wheat cultivars Huapei 3 × Yumai 57 (Triticum aestivum L.). A genetic map was constructed based on 305 marker loci, consisting of 283 SSR loci and 22 EST-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers in the genome. QTL analyses were performed using a mixed linear model approach. Two main-effect QTLs and two pairs of digenic epistatic effects were detected for heading date on chromosomes 1B, 2B, 5D, 6D, 7A, and 7D at three different environments in 2005 and 2006 cropping seasons. A highly significant QTL with an F-value 148.96, designated as Qhd5D, was observed within the Xbarc320-Xwmc215 interval on chromosome 5DL, accounting for 53.19% of the phenotypic variance and reducing days-to-heading by 2.77 days. The Qhd5D closely links with a PCR marker Xwmc215 with the genetic distance 2.1 cM, which can be used in molecular marker-assisted selection (MAS) in wheat breeding programs. Moreover, the Qhd5D was located on the similar position of well-characterised vernalization sensitivity gene Vrn-D1. We are also spending more efforts to develop near-isogenic lines to finely map the Qhd5D and clone the gene Vrn-D1 through map-based cloning. The Qhd1B with additive effect on heading date has not been reported in previous linkage mapping studies, which might be a photoperiod-sensitive gene homoeologous to the Ppd-H2 gene on chromosome 1B. No main-effect QTLs for heading date were involved in epistatic effects.

RVA and Farinograph Properties Study on Blends of Resistant Starch and Wheat Flour

Resistant starch (RS) is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis (RVA) and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS (RS3 and RS2) and three wheat flours. The wheat flours represented strong gluten wheat (SGW), intermediate gluten wheat (IGW), andweak gluten wheat (WGW) flours, at different levels of RS substitution (0, 5, 10, 15, and 20%). The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities of wheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time (r=1.000, 0.958, 0.894), and highly negatively correlated with the mixing tolerance index (r=-0.890). Data from this study can be used for the development of dough-based products. It also provides a basis for RS-wheat flour blends and quality evaluation in the food industry.

A Genetic Map Constructed Using a Doubled Haploid Population Derived from Two Elite Chinese Common Wheat Varieties

Genetic mapping provides a powerful tool for the analysis of quantitative trait loci (QTLs) at the genomic level. Herein, we report a new genetic linkage map developed from an F(1)-derived doubled haploid (DH) population of 168 lines, which was generated from the cross between two elite Chinese common wheat (Triticum aestivum L.) varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat (SSR) and 22 expressed sequence tag (EST)-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed.

Genetic analysis of grain yield and leaf chlorophyll content in common wheat

Chlorophyll content is positively correlated with photosynthetic rate. However, little is known about the genetic correlation between grain yield and chlorophyll content in the same wheat mapping population. The primary goal of the study was to detect the genetic basis of grain yield and chlorophyll content and their possible roles in the genetic improvement of grain yield in wheat. Here, quantitative trait loci (QTLs) for grain yield and chlorophyll content were studied using a set of 168 doubled haploid (DH) lines derived from a cross between two elite Chinese wheat cultivars, Huapei 3×Yumai 57. The DH population and parents were evaluated for grain yield and chlorophyll content in three environments. A total of 11 additive QTLs and 6 pairs of epistatic QTLs were detected for grain yield and chlorophyll content. Loci, such as Xcfd53, Xwmc718 , and Xwmc215 on chromosomes (e.g. 2D, 4A, and 5D) simultaneously controling grain yield and chlorophyll content, showed tight linkages or pleiotropisms. Three nove...

Effect of gluten on pasting properties of wheat starch.

The effect of gluten on pasting properties of wheat starch was studied to provide a scientific basis for the application of gluten in food production and quality improvement in wheat breeding. The pasting properties of blends were analyzed using PH1391 wheat starch mixed with five different additions of three kinds of gluten (strong-, medium-, and weak-gluten) and the structures of network were observed with microscope. The significant downtrends of peak viscosity, trough viscosity, final viscosity, area of viscosity, setback, and peak time were observed with the increase in the addition of gluten. In general, the average value of them decreased respectively by 3.6, 4.8, 3.4, 3.8, 4.0, and 1.18% of those corresponding indexes of pure starch for every 2% increase in gluten. The decreasing rate of the indexes mentioned above exceeded more than 2% except peak time, but there were no significant influence of gluten addition on breakdown, pasting temperature and pasting time. The inter layer composed of gluten was not observed when the addition of gluten was 10%, as the compound formed of gluten inlaid in the paste of starch, but obvious inter layer was detected when the addition of gluten was 18%. There was significant or remarkable difference among the effects of three different kinds of gluten on the peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but it had no significant difference among the effects of different glutens on pasting temperature and pasting time. The descending order of the effect of different glutens on peak viscosity, trough viscosity, and area of viscosity was strong-, medium-, and weak-gluten, but the order of them for setback was opposite. Both addition and types of gluten significantly affected peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but there were no significant effects of it on peak time and peak temperature.

Effect of HMW-GS 6 ＋ 8 and 1.5 ＋ 10 from Synthetic Hexaploid Wheat on Wheat Quality Traits

To determine the effect of 6 + 8 and 1.5 + 10 HMW-GS of synthetic hexaploid wheat (SHW) on main quality parameters of wheat, a set of recombinant inbred lines (RILs) derived from the cross between a SHW with N, 6 + 8, 1.5 + 10 HMW-GS and a cultivar Chuanyu 12-1 (CY12-1) with 1, 7 + 8, 2 + 12 were planted in three environments in 2005 and 2006 and totally 16 quality parameters were tested for each line. Significant differences in all tested quality parameters but flour yield were observed between the two parents. The mean values of the RILs were intermediate to the parents for grain and protein parameters and some farinograph parameters, flour water absorption (FWA), and farinograph softening (SOF) but beyond parents at dough stability time (DST), breakdown time (BRT), quality number (QN), noodle score (NS), and loaf volume (LOV). All of the quality traits, especially in grain hardness (GH), zeleny sedimentation volume (SED), and most of farinograph parameters had significant difference between the different HMW-GS components. The effects of different alleles of HMW-GS at same locus (Glu-A1 or Glu-B1 or Glu-D1) on the different quality parameters were also different and affected by the other two loci. For most of parameters tested, 6 + 8 was better than 7 + 8 and there was no difference between 1.5 + 10 and 2 + 12. End-use quality was greatly influenced by components of HMW-GS. The components of 1, 6 + 8, 1.5 + 10 had the highest LOV and bread score (BS) values, whereas the components of 1, 7 + 8 and 1.5 + 10 had the highest NS values. Noodle score performed a positive linear relationship with falling number (FN) and its relationships to other quality parameters were affected by environments. Loaf volume had a significant negative relationship to SOF and positive associations with most of quality parameters. It could be concluded that HMW-GS 6 + 8 from SHW had better overall quality characteristics than 7 + 8, whereas the effects of 1.5 + 10 on quality was different in respect to quality parameters and the HMW-GS components. Synthetic hexaploid wheat with subunits 6 + 8 and 1.5 + 10 had the potentials to improve the end-use quality of wheat cultivars.

Textural Characteristics and Sensory Evaluation of Cooked Dry Chinese Noodles Based on Wheat-Sweet Potato Composite Flour

Effects of sweet potato flour (SPF) addition on dry Chinese noodles prepared from five wheat flours with variable quality (weak to very strong) were investigated. Color values expressed as L*, a* and b* were markedly affected by the levels of SPF. SPF addition reduced the springiness, cohesiveness, and resilience of the cooked noodles, but exerted varied effects on hardness and adhesiveness. Total scores of noodle samples prepared from composite flours decreased significantly with exception of very strong or strong flour. However, the reduction of total scores in wheat-SPF noodles was mainly due to decreasing of color and taste scores.

Phytic Acid Contents of Wheat Flours from Different Mill Streams

Abstract The phytic acid contents of eight fractions of wheat flours from different mill streams and those in wheat brans, which were separated by different sieves into various sizes, were determined and analyzed. A rapid method for phytic acid assay by adding thioglycolic acid (mercapto acetic acid) with 2,2-bipyridine was used, with an acidic iron-III-solution of known iron content. The amount of phytate was indicated by the decrease in iron in the supernatant. Significant differences were observed in phytic acid content among different milling streams and different cultivars (P > 0.05). On an average, coarse bran had the highest phytic acid content (53.85 mg g−1), and the shorts had 28.48 mg g−1. The B5 break flour had a higher phytic acid content (4.8 mg g−1) than the B7 (2.75 mg g−1) and B8 (2.03 mg g−1) reduction flours. Lower values were found in the B3, B6 and B7 flours (1.07, 0.79, and 0.76 mg g−1, respectively). The phytic acid contents of bran decreased with smaller bran sizes, ranging from 54 to 5.09 mg g−1.

Variations in Amino Acid and Protein Contents of Wheat During Milling and Northern-Style Steamed Breadmaking

ABSTRACT To determine the variations of amino acid and protein during milling and steamed breadmaking, two types of wheat cultivars belonging to soft and hard wheat types were used. The results showed that losses occurred in 17 amino acids during milling. The mean loss of threonine (18.0%) was the highest, which was followed by proline (15.5%), methionine (15.1%), and histidine (15.1%). The losses of tyrosine and lysine were the lowest (8.1 and 9.7%, respectively). Losses were also found for 17 amino acids during steamed breadmaking. The highest loss was observed in alanine (17.1%), with tyrosine (12.5%) close behind, and leucine (4.3%) exhibiting the lowest loss. The mean protein contents for whole-wheat meal, flour, and steamed bread prepared from the test materials were 15.25, 14.27, and 14.33%, respectively. This meant that protein content decreased during milling; however, a slight increase was observed during steamed breadmaking. Amino acid scores of lysine in whole-wheat meal, flour, and steamed br...

Protein Content and Amino Acid Composition in Grains of Wheat-Related Species

Abstract The protein content and amino acid composition for 17 wheat-related species (WRS) and three common wheats (control) were determined and analyzed, and the essential amino acids (EAAs) in WRS were evaluated according to FAO/WHO amino acid recommendations. The results showed that the mean protein content for WRS was 16.67%, which was 23.21% higher than that for the control. The mean contents (g 100 g−1 protein) of most amino acids for WRS were lysine 2.74%, threonine 2.83%, phenylalanine 4.17%, isoleucine 3.42%, valine 3.90%, histidine 2.81%, glutamic acid 29.96%, proline 9.12%, glycine 3.59%, alanine 3.37%, and cysteine 1.57%, which were higher than those for the control. The contents of the other 6 amino acids for WRS were lower than those for the control. The materials (Triticum monococcum L., Triticum carthlicum Nevski, and Triticum turgidum L.) contained relatively high concentration of the most deficient EAAs (lysine, threonine, and methionine). Comparing with FAO/WHO amino acid recommendations, the amino acid scores (AAS) of lysine (49.8%), threonine (70.7%). and sulfur-containing amino acids (74.8%) were the lowest, which were considered as the main limiting amino acids in WRS. It was observed that the materials with Triticum urartu Tum. (AA) and Aegilops speltoides Tausch. (SS) genomes had relatively high contents of protein and EAA. The contents of protein (16.91%), phenylalanine (4.78%), isoleucine (3.53%), leucine (6.16%), and valine (4.09%) for the diploid materials were higher than those for the other materials. These results will provide some information for selecting parents in breeding about nutrient quality and utilization of fine gene in wheat.