Identification of KASP markers and putative genes for pre-harvest sprouting resistance in common wheat(Triticum aestivum L.)

Common wheat(Triticum aestivum L.) is the most important crop in the world and a typical allopolyploid with a large and complex genome. Pre-harvest sprouting(PHS) leads to a significant reduction in grain quality worldwide. PHS is a complex trait with related QTL located on different chromosomes.However, the study of markers and genes related to PHS resistance is limited especially for whitegrained wheat. Four pairs of near isogenic lines(NILs) from a white-grained wheat cross of Chara × DM5637B...     

Genetic analysis of resistance to spot blotch disease in wheat (Triticum aestivum L.) in Zambia

Understanding the genetics of resistance to spot blotch disease, caused by Bipolaris sorokiniana (Sacc.) Shoem, is important to design an appropriate breeding strategy to improve the trait. The objective of this study was to determine the gene action and mode of inheritance of resistance to spot blotch in wheat. Eight genotypes with varying resistance to the disease were crossed in a full diallel mating design. Parents and their progenies were evaluated for spot blotch resistance. Data were analyzed using Hayman’s diallel analysis. The results suggested the importance of additive gene effects in controlling the resistance to spot blotch in the materials under study. No epistasis, maternal, or reciprocal effects were detected. Resistance to spot blotch exhibited partial dominance. Therefore, exercising selection for resistance in the early segregating generation should be an effective approach because of the predominance of additive gene effects. The Wr/Vr graph showed that the parents 30SAWSN5 (P3) and Coucal (P4) possessed more dominant genes, which makes them particularly suitable for inclusion in breeding for resistance to spot blotch.     

Genome-wide association study of seedling nitrogen-use efficiency-associated traits in common wheat(Triticum aestivum L.)

Nitrogen(N) fertilizer application is essential for crop-plant growth and development. Identifying genetic loci associated with N-use efficiency(NUE) could increase wheat yields and reduce environmental pollution caused by overfertilization. We subjected a panel of 389 wheat accessions to N and chlorate(a nitrate analog) treatments to identify quantitative trait loci(QTL) controlling NUE-associated traits at the wheat seedling stage. Genotyping the panel with a 660K single-nucleotide polymorphis...     

Structural changes in root tips of wheat (Triticum aestivum L.) in response to olive oil mill wastewater

Toxic effects of the wastewater were investigated ultrastructurally in root tips of Triticum aestivum. As a result, wall and nuclear degradations, disruptions in all cytoplasmic membranes, irregular nucleus shapes and cellular organization defects were densely detected. Besides, germination ratio, total protein contents, DNA contents and root-shoot growth were found to be decreased significantly when compared to the control group. Results were compared with those of recent studies regarding excessive Na+, Fe+2, P, polyphenols and acidic pH toxicity.     

Metabolite profiling of the response to high-nitrogen fertilizer during grain development of bread wheat (Triticum aestivum L.)

Wheat yield and quality are dependent largely on nitrogen (N) availability. In this study, we performed the first metabolomic analysis of the response to high-N fertilizer during wheat grain development using non-targeted gas chromatography-mass spectrometry (GC–MS). Quality parameter analyses demonstrated that high-N fertilizer application led to a significant increase in grain protein content and improvement in starch and bread-making quality. Comparative metabolomic profiling of six grain developmental stages resulted in identification of 74 metabolites, including amino acids, carbohydrates, organic acids and lipids/alcohol, which are primarily involved in carbon and N metabolism. Under high-N fertilizer treatment, numerous metabolites accumulated significantly during grain development. Principal component analysis revealed two principal components as being responsible for the variances resulting from N-fertilizer treatments. Metabolite–metabolite correlation analysis demonstrated that the high-N treatment group had a greater number of positive correlations among metabolites, suggesting that high-N fertilizer treatment induced a concerted metabolic change that resulted in improved grain development. Particularly, the high-N treatment-mediated significant accumulation of metabolites involved in the TCA cycle, starch and storage protein synthesis could be responsible for the improvement of grain yield and quality. Our results provide new insight into the molecular mechanisms of wheat grain development and yield and quality.     

Definition of the low molecular weight glutenin subunit gene family members in a set of standard bread wheat (Triticum aestivum L.) varieties

Low-molecular-weight glutenin subunits (LMW-GS) are a class of seed storage proteins that play a major role in the determination of the viscoelastic properties of wheat dough. The LMW-GSs are encoded by multi-gene families at the Glu-A3, Glu-B3 and Glu-D3 loci, with more than 15 genes present in most bread wheat varieties. However, the genic profile associated with different alleles has not been clearly defined. Here, the LMW-GSs in a set of standard varieties were analyzed using molecular markers. In most cases, each Glu-3 allele was represented by a specific haplotype; however, some alleles were undistinguishable. The Glu-A3e and Glu-A3g alleles showed an identical marker haplotype, as did the alleles Glu-B3c and Glu-B3d, and Glu-B3f and Glu-B3ab. In contrast, two haplotypes among varieties designated Glu-D3c were differentiated. The marker profiles present at the Glu-D3 locus exhibited less variation compared to the genes at the Glu-A3 and Glu-B3 loci. Results show the potential of the LMW-GS gene marker system in the characterization of the LMW-GS alleles present in specific bread wheat varieties, and its reconciliation with protein-based nomenclature. This approach will advance the understanding of the contribution of each of the LMW-GS gene alleles in the control of the end-use quality.     

Bed planting of wheat(Triticum aestivum L.)improves nitrogen use efficiency and grain yield compared to flat planting

Conventional flat planting is commonly used for growing wheat in Pakistan and the crop is irrigated by flood irrigation, but it leads to ineffective use of applied nitrogen owing to poor aeration and leaching and volatilization losses. The practice also results in greater crop lodging, lower water use efficiency, and crusting of the soil surface. In contrast, bed planting of wheat not only saves water but improves fertilizer use efficiency and grain yield. Three years of pooled data from the present study showed that wheat planting on beds and nitrogen application at 120 kg ha-1produced 15.06% higher grain yield than flat planting at the same nitrogen rate. Similarly, 25.04%, 15.02%, 14.59%, and 29.83% higher nitrogen uptake, nitrogen use, and agronomic and recovery efficiencies, respectively, were recorded for bed compared to flat planting. Wheat planting on beds with a nitrogen application of80 kg ha-1gave a yield similar to that of flat planting with 120 kg ha-1nitrogen. However,the economic return was 29% higher in bed planting as compared to flat planting, when nitrogen was applied at 120 kg ha-1.     

Use of Student's t statistic as a phenotype of relative consumption preference of wheat (Triticum aestivum L.) grain

Whole-grain wheat (Triticum aestivum L.) products provide essential nutrients to humans, but bran attributes may hinder consumption. Differences in grain attributes including flavor/aroma can be identified using the house mouse (Mus musculus L.) as a model system. A potential application of this model system is to identify genes or quantitative trait loci (QTLs) conferring consumption-related traits using genetic mapping. These analyses require a quantitative phenotype to test marker–trait associations. Two-choice feeding trials are common in consumption studies, but do not provide an independent, quantitative phenotype. The objective of this study was to examine the use of ‘check’ varieties against which to compare sample varieties to generate Student's t values for use as phenotypic values. Two checks, which had previously been identified as “Yummy” and “yucky” (Y, y) were compared against each sample variety. The resulting t values provided an independent quantitative phenotype of the sample varieties.     

Structure,chemical composition and enzymatic activities of pearlings and bran obtained from pearled wheat (Triticum aestivum L.) by roller milling

While abrasive pearling (also referred to as debranning) of wheat kernels prior to milling increases the quality of the resultant flour for producing bread, the potential applications of the co-products of pearling is largely unknown. We studied the impact of different degrees of pearling (0, 3, 6, 9 and 12% by weight) on the composition of pearlings and bran obtained when subsequently roller milling pearled wheat kernels. Pearling does not remove the kernel outer tissues homogeneously as abrasion affects especially the accessible parts of the kernels. Nevertheless, the first 3% removed consisted of mainly pericarp. With 6% or more removed, a significant amount of starchy endosperm ended up in the pearlings. The starting bran material and bran obtained by subsequent roller milling of pearled wheat kernels had similar compositions but the latter had a lower average particle size. Moreover, removal of the outermost kernel layers substantially decreased the enzyme activity levels in the bran.     

Intercropped wheat (Triticum aestivum L.) and bean (Vicia faba L.) as a whole-crop forage: effect of harvest time on forage yield and quality

Abstract Sole crops and intercrops of wheat (Triticum aestivum L.) and bean (Vicia faba L.), at three harvest dates, representing successive growth stages, were evaluated for biomass production of whole‐crop forage and quality characteristics of crude protein (CP), neutral‐detergent fibre (NDF), acid‐detergent fibre (ADF), water‐soluble carbohydrate (WSC) concentrations and ash content. These tests were carried out for two field experiments, respectively, drilled during the spring of 1997 and autumn of 1997 on Imperial College Farm, Wye, UK. Results indicated that optimum forage yield and quality were obtained from the second to third harvest dates for the spring‐drilled experiment and the second harvest for the autumn‐drilled experiment. Wheat and bean intercrops were higher in total forage dry matter (DM) yield than either wheat or bean grown as sole crops. Field bean intercropped with wheat led to increased forage quality (CP and NDF concentrations) compared with sole wheat, and higher WSC concentrations compared with sole bean. Intercrops also enhanced weed suppression compared with sole bean. It is suggested that winter wheat–bean intercrops may have considerable potential as a moderate‐yielding, relatively high‐quality, low‐input and environmentally benign forage crop with considerable potential with regard to yield and quality and warrant further study.     

Chemical structure of flavonoid compounds in wheat (Triticum aestivum L.) flour that contribute to the yellow colour of Asian alkaline noodles

Colour is an important criterion of quality in Asian noodles prepared from bread-wheat flour and ranges from white to cream for white salted noodles to a bright yellow for alkaline noodles. A high-performance liquid chromatographic protocol for the analysis of naturally occurring flavonoids and related phenolic compounds in wheat was developed to identify the compounds responsible for the yellow colour of alkaline noodles. The separation system consisted of a C18 reversed-phase column and a gradient system of water/formic acid (99:1,v/v) (A) and methanol/acetonitrile/formic acid (95:4:1,v/v/v) (B). A post column derivatisation technique was employed to identify the compounds that turned yellow at alkaline pH. A comparison of the HPLC profiles of water, alkaline water and hydroxylamine soluble fractions revealed that the level of compounds contributing to yellow alkaline noodle colour was highest in the hydroxylamine extract. Two flavonoid apigenin-C-diglycosides and their Wessely–Moser isomers, together with their sinapic acid esters, were isolated and identified by absorbance spectroscopy, ES-MS spectrometry and ¹³C NMR. These flavone-C-diglycosides were found to be the major components responsible for the alkali-induced change in noodle colour and are relatively stable at ambient temperature. Furthermore the compounds are located only in the germ (embryo+scutellum tissue) of wheat grains and hence their presence in flour must represent a redistribution during the milling process.     

Effect of allelic variation at the Glu-3/Gli-1 loci on breadmaking quality parameters in hexaploid wheat (Triticum aestivum L.)

Low molecular weight glutenin subunits (LMW-GS) encoded by the Glu-3 loci are known to contribute to wheat breadmaking quality. However, the specific effect of individual Glu-3 alleles is not well understood due to their complex protein banding patterns in SDS-PAGE and tight linkage with gliadins at the Gli-1 locus. Using DNA markers and a backcross program, we developed a set of nine near isogenic lines (NILs) including different Glu-A3/Gli-A1 or Glu-B3/Gli-B1 alleles in the genetic background of the Argentine variety ProINTA Imperial. The nine NILs and the control were evaluated in three different field trials in Argentina. Significant genotype-by-environment interactions were detected for most quality parameters indicating that the effects of the Glu-3/Gli-1 alleles are modulated by environmental differences. None of the NILs showed differences in total flour protein content, but relative changes in the abundance of particular classes of proteins cannot be ruled out. On average, the Glu-A3f, Glu-B3b, Glu-B3g and Glu-B3i_Man alleles were associated with the highest values in gluten strength-related parameters, while Glu-A3e, Glu-B3a and Glu-B3i_Chu were consistently associated with weak gluten and low quality values. The value of different Glu-3/Gli-1 allele combinations to improve breadmaking quality is discussed.     

Influence of precipitations and sunshine hours on yield of paddy field grown wheat (Triticum aestivum L.) in Northern Kyushu,Japan

ABSTRACT

Relationships between wheat (Triticum æstivum L.) yield components and growing season weather conditions (e.g. temperature, precipitation, and sunshine duration) were investigated for a rice-wheat rotation paddy system situated in Northern Kyushu, Japan over a 17-year period (2000–2016). A 1.0 mm increase in precipitation from 21 to 32 days after sowing decreased wheat yield by about 27 kg ha^?1 at early seedling stage with one to two leaves (Zadoks (Z) growth stage Z1.1–1.2). Number of tillers and spikes showed significant negative correlations to the amount of precipitation during the period. An hour increase in mean daily sunshine hours from 94 to 111 days after sowing resulted in an 328 kg ha^?1 rise in grain yield at stem elongation stage with the first and second node detection (Z3.1–3.2). The grain number per square meter also showed strong positive correlations to sunshine hours during the same period. However, this positive effect of sunshine was negated when precipitation exceeded about 30 mm during the early seedling stage. Consequently, precipitations at early seedling stage and sunshine hours at stem elongation stage mostly determined wheat yield in Northern Kyushu paddy field. Increasing precipitations during the early seedling stage highlights the pressing need for effective paddy field drainage management from wheat sowing through harvest.

Abbreviations: CP: Chikushi Plains; FARC: Fukuoka prefectural Agriculture and Forestry Research Center; SARC: Saga prefectural Agricultural Research Center; DAS: days after sowing     

黄淮麦区21个小麦品种中春化基因VRN1的组成分析

为了明确黄淮麦区小麦品种的春化基因组成,采用序列特异性PCR扩增技术分析了21个小麦品种春化基因VRN1的显隐性组成特性.结果表明,所检测品种中没有发现VRN1在A基因组为显性(Vrn-A1)的基因型;偃展1号中VRN1在B和D基因组均为显性;周麦19、豫农949、郑麦004、洛麦21、豫麦18、矮抗59和偃展4110 中,春化基因VRN1在D基因组中为显性;豫麦49、豫麦70、小偃81、郑麦366、豫麦70-36、温麦8号、洛旱2号、温麦19、豫农301、周麦16、平安3号、众麦1号和阜麦936中,春化基因VRN1在A、B和D基因组均为隐性.     

Influence of competition,irrigation levels and nitrogen fertilization on protein content and protein yield of three spring wheat (Triticum aestivum L.) cultivars

Protein content and protein yield of three spring wheat cultivars differing in morphological and physiological growth characters were found to be influenced by intercultivar competition, irrigation levels and nitrogen fertilization. The protein content of the tall cultivar C 306 and the protein yield of the dwarf cultivar HD 2160 were more than the other cultivars. Binary mixed stands were not superior to the better component cultivar. Intercultivar competition increased the protein content of dwarf and semi-dwarf cultivars, but decreased the protein content of tall cultivar. On the other hand, protein yield of the dwarf cultivar decreased and that of tall cultivar increased when grown in mixed stands. Protein yield of semi-dwarf cultivar increased when grown with dwarf cultivar, but decreased when grown with tall cultivar. Two or three irrigations increased the protein content and protein yield of all the three cultivars and their mixed stands over one irrigation. Protein content and protein yield of the cultivars and their mixed stands were higher when 150 kg N/ha was applied than when 80 kg N/ha was applied.     

Effect of the 1BL.1RS translocation and of the Glu-B3 variation on fifteen quality tests in a doubled haploid population of wheat (Triticum aestivum L.)

To investigate the impact of 1BL.1RS translocation on protein content, starch quality, dough rheology, RMT volumes and other quality traits, a doubled haploid population was created and sown in a two-year field experiment. Translocated genotypes accumulated more proteins in the endosperm than non-translocated genotypes. Decrease in the gelatinization of starch was associated with the 1BL.1RS translocation. As for rheological parameters, adapted to bread types not requiring high mixing energy, the 1BL.1RS translocation significantly reduced the elasticity, tenacity and strength of the dough compared to allele c of Glu-B3. Tolerance to over-mixing was also significantly lower in translocated DH lines. In contrast to previously published work, the presence of allele Glu-D3 c resulted in significantly higher tenacity, and thus strength, compared with the allele Glu-D3 b in the present DH population. The final baking test performed on the DH lines of the population, combining favourable alleles for dough rheology and high protein content, demonstrated that in some cases lower tenacity induced by the 1BL.1RS translocation or by Glu-B3 b increases the volume of the loaves.     

Effects of supplemental irrigation based on soil moisture levels on photosynthesis,dry matter accumulation,and remobilization in winter wheat (Triticum aestivum L.) cultivars

Two winter wheat (Triticum aestivum L.) cultivars, namely Jimai22 (JM22) and Zhouyuan9369 (ZY9369), were used to study the effects of a new irrigation policy, supplemental irrigation (SI) based on soil moisture levels, photosynthesis, dry matter accumulation, and remobilization from 2009 to 2011 in Northern China. Two SI treatments were designed based on relative soil moisture contents in the 0–140 cm soil layer: (1) the target soil relative water contents were 75% of field capacity (FC) at jointing and 65% of FC at anthesis (W1), 75% and 70% (W2) in 2009–2010, and (2) the target soil relative water contents were 75% at jointing and 75% at anthesis (W1′), 75% and 80% (W2′) in 2010–2011. Rain-fed treatment (W0) was used as control. Results showed that SI significantly improved the biomass, grain yield and water use efficiency (WUE) of both wheat cultivars. The biomass and grain yield of W1 and W1’ treatments were higher than those of others. The net photosynthetic rate, the actual photochemical efficiency of flag leaf, the accumulation of dry matter, and its remobilization from the vegetative parts to the grains after anthesis in W1 and W1’ treatments were significantly higher than in the other treatments. By contrast, the WUE and irrigation efficiency of W2 and W2’ were significantly lower than those of W1 and W1’. Under the experimental conditions, ‘JM22’ showed higher photosynthetic rate in the last stage of grain filling, more spike number per ha, more kernels per spike, higher 1000-kernels weight and eventually higher WUE than ‘ZY9369’.     

Cloning,expression and functional analysis of HMW glutenin subunit 1By8 gene from Italy pasta wheat (Triticum turgidum L. ssp. durum)

Cloning and functional analysis of high molecular weight wheat glutenin subunit (HMW-GS) 1By8 from Italy durum cultivar Simeto was carried out in this study. All HMW-GS from Simeto were separated and characterized by appropriate electrophoresis methods, reversed-phased high performance liquid chromatography (RP-HPLC) and mass spectrometry (MS). The complete gene encoding 1By8 subunit was amplified by allele-specific PCR primers, including an upstream sequence of 857 bp and an open reading frame (ORF) of 2166 bp encoding a mature protein of 720 amino acid residues. The promoter sequence, containing -300 element (cereal glutenin gene control element) and enhancer was highly conserved among HMW-GS genes. Comparison with the sequence of subunit 1By9 from bread wheat demonstrated 99% identity with the main difference being that the 1By8 subunit possesses an additional insertion of 15 amino acid residues (QYPASQQQPA QGQQG) at position 342 and two residue substitutions at position 78 (leucine/proline) and 442 (arginine/glutamine). The molecular weight differences between MALDI-TOF-MS and deduced amino acid sequence of the coding gene revealed the possibility of some kinds of post-translational modifications present in 1By8 subunit. The protein subunit expressed in Escherichia coli showed a very similar mobility to the endogenous 1By8 of Simeto on SDS-PAGE. The function of the isolated protein on wheat processing quality was determined by 10 g Mixgraph analysis. Results demonstrated that addition of y-type HMW glutenin subunits into the base flour had significant positive effects on main mixing parameters and significant difference in effects were observed among different y-type subunits.     

大豆对SMV1号株系的抗性遗传分析及抗病基因的SSR标记

定,结果表明：F1在接种后表现抗病,F2群体分离比例为3 (抗)∶1 (感),对F2衍生的F2∶3家系接种鉴定,纯合抗病家系、抗感分离家系和纯合感病家系的比率符合1∶2∶1,表明东农93-046对SMV1号株系的抗性由一对显性基因（RSMV1）控制。并利用东农93-046（R）×Conrad（S）的正反交组合F2进行抗性鉴定,结果正反交后代均表现为3∶1的分离比例,无细胞质效应,进一步证明了东农93-046是受一对基因控制的抗性种质。经改良的分离群体组群分析法研究发现,东农93-046抗SMV1的位点（RSMV1）位于F连锁群上,与SSR标记的连锁顺序为HSP176、Satt114、RSMV1、Satt510、Sct_033、Satt334、Satt362,连锁距离分别为6.6cM、4.3cM、RSMV1、6.6cM、5.1cM、6.3cM、17.3cM.。根据标记HSP176选择基因型纯合和杂合的抗病植株,其符合率分别达到100.0%和94.5%。