Wheat, one of the world’s major crops, is seriously affected by fungal diseases, especially in regions with high moisture and moderately warm temperatures. This paper reviews various molecular and ...conventional techniques that are used to identify genotypes with resistance alleles associated with Fusarium head blight (FHB) diseases. Quantitative trait loci (QTL) type II, designated as Fhb1, are frequently applied in plant breeding, and the newly recognized genes related to resistance to this fungal disease give extra insights into marker-assisted selection (MAS). Molecular markers are robust tools that may be routinely used in MAS for the mapping of resistance genes in crop breeding. FHB resistance is polygenic, and different resistance genes could be conveyed into a single genotype by MAS, which might ensure greater resistance to FHB disease. In conclusion, different researchers have used various techniques to control FHB resistance, such as MAS, gene pyramiding (through backcross), and molecular markers (association with resistance QTLs or genes).
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Sodium dodecyl sulfate (SDS) sedimentation volume has long been used to characterize wheat flours and meals with the aim of predicting processing and end-product qualities. In order to survey the ...influence of low-molecular-weight glutenin subunits (LMW-GSs) at Glu-B3 locus on wheat SDS sedimentation volume, a total of 283 wheat (Triticum aestivum L.) varieties including landraces and improved and introduced cultivars were analyzed using 10 allele-specific PCR markers at the Glu-B3 locus. The highest allele frequency observed in the tested varieties was Glu-B3i with 21.9% in all varieties, 21.1% in landraces, 25.5% in improved cultivars, and 12% in introduced cultivars. Glu-B3 locus represented 8.6% of the variance in wheat SDS sedimentation volume, and Glu-B3b, Glu-B3g, and Glu-B3h significantly heightened the SDS sedimentation volume, but Glu-B3a, Glu-B3c, and Glu-B3j significantly lowered the SDS sedimentation volume. For the bread-making quality, the most desirable alleles Glu-B3b and Glu-B3g become more and more popular and the least desirable alleles Glu-B3a and Glu-B3c got less and less in modern improved cultivars, suggesting that wheat grain quality in China has been significantly improved through breeding effort.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Improvement of flour colour is an important breeding objective for various wheat-based end-products. The objectives of this study were to identify quantitative trait loci (QTL) for flour colour ...components and yellow pigment content (YPC), using 240 recombinant inbred lines (RILs) derived from a cross between the Chinese wheat cultivars PH82-2 and Neixiang 188. Field trials were performed in a Latinized α-lattice design in Anyang and Jiaozuo, Henan Province and Taian, Shandong, in the 2005-2006 and 2006-2007 cropping seasons providing data for six environments. One hundred and eighty-eight polymorphic SSR markers, rye secalin marker Sec1, STS markers YP7A for a phytoene synthase gene (Psy-A1), and four glutenin subunit markers, were used to genotype the population and construct the linkage map for subsequent QTL analysis. Two major QTL were detected for YPC, associated with 1RS (1B.1R translocation) and the Psy-A1 (7A) gene, explaining 31.9% and 33.9% of the phenotypic variances, respectively. 1RS also had large influences on Fa*, Fb*, KJ, NL*and Nb*, and Psy-A1 genes showed large effects on Fa*, Fb*, Kj, Fci, NL*, Na* and Nb*, explaining from 4.5 to 26.1% and 4.3 to 35.9% of the phenotypic variances, respectively. In addition, QTL for flour colour parameters and yellow pigment content were also detected on chromosomes 1A and 4A, accounting for 1.5-4.1% of the phenotypic variance. The genetic effect of the 1B.1R translocation on flour colour parameters was also discussed.
Polyphenol oxidase (PPO) is primarily responsible for the enzymatic browning of Asian noodles and other flour products. In order to investigate how the allelic variability of PPO genes affect the ...kernel PPO activities, we used the two currently available sequence-tagged-site (STS) markers of PPO genes PPO18 and STS01 located on chromosomes 2A and 2D, for detecting PPO allelic variability in 300 F4 plants obtained from hybridization of Yangmai 158 × Huaimai 18 and 362 other wheat cultivars. Our results confirmed previous findings that variations in the alleles of PPO genes located on chromosomes 2A and 2D contributed to approximately 50% of the PPO activities. In addition, we divided the average PPO activity of the varieties that contained only one gene by the average PPO activity of all varieties. We found that the contribution of the two PPO genes on chromosome 2A was as much as twice that of the two PPO genes on chromosome 2D. PPO activity was reduced by 23.7% and 8.5% by the allelic genes PPO-2Ab and PPO-2Da, respectively, and increased by 18.7% and 20.8% by PPO-2Aa and PPO-2Db. Our study shows that the allelic genes PPO-2Ab and PPO-2Da are responsible for maintaining the PPO activities at low and medium levels, and PPO-2Aa, and PPO-2Db at medium high levels. These findings emphasize the selection of the PPO-2Ab allelic gene for breeding wheat varieties with low PPO activity.
Improvement of processing quality is important for various wheat-based end products. A recombinant inbred line (RIL) population derived from a cross between the Chinese wheat cvv. PH82-2 (hard) and ...Neixiang 188 (soft) was sown at 3 locations across two seasons to map quantitative trait loci (QTLs) for milling, gluten quality, flour pasting properties, and Chinese white salted noodle (CWSN) qualities. One hundred and eighty-eight microsatellite loci, one rye secalin marker Sec1, one STS marker YP7A, one CAPs marker for the Pinb-D1b allele, and four glutenin subunit markers were used to genotype the population and construct a linkage map for subsequent QTL analysis. In total, 53 QTLs for 16 quality parameters were mainly mapped to glutenin loci Glu-A3 (Glu-A3a:Glu-A3d), Glu-B1 (Bx7+By9:Bx14+By15), and Glu-D1 (Bx2+By12:Bx5+By10), and the grain hardness (Pinb-D1a:Pinb-D1b) locus. The-high-molecular weight glutenin subunits (HMW-GS) 5+10 at the Glu-D1 locus showed large effects on mixograph peak time (MPT), mixograph 8min width (MTxW), and weakening slope (WS), accounting for 43.1%, 24.2%, and 39.7% of the phenotypic variance, respectively. In contrast, the 1RS (1B.1R translocation) showed large negative effects on MTxW, explaining 42.2% of the phenotypic variance. Two important QTLs were detected for Rapid Viscosity Analyzer (RVA) parameters: one for RVA final viscosity (RFV) near the 1RS and the other for RVA setback (RSb) associated with the Glu-B1 locus, explaining 21.6% and 12.3% of the phenotypic variance, respectively. Two QTLs for noodle adhesiveness were identified: one occurred on chromosome 1A and the other was associated with Glu-B1. Two QTLs for noodle springiness, one associated with the 1RS showing a negative effect on noodle quality and the other mapped to the Ha locus on chromosome 5DS, accounted for 9.4% and 8.1% of the phenotypic variance, respectively. In addition, the Ha locus also showed large effects on flower protein content (FPC), mixograph peak width (MPW), and RVA parameters, especially RVA pasting temperature (RPT), explaining 71.5% of the phenotypic variance.
Global warming is asymmetric, with the increase in temperature at night being greater than that during the day. In this study, we conducted night warming treatments using a passive heating device on ...the wheat variety ‘Yangmai 18′ grown in culture pots in an experimental field. The night warming treatments were performed from the tillering stage to the jointing stage (NWT-J), from the jointing stage to the booting stage (NWJ-B), and from the booting stage to the anthesis stage (NWB-A). A non-warming treatment was used as a control (NN). Post-anthesis heat (H) stress was performed during the grain-filling stage. The results showed that treatments NWT-J and NWJ-B significantly enhanced grain yield by increasing the 1000-grain weight, while the NWJ-B treatment showed the highest impact. Night warming treatments at early growth stages significantly prevented the grain-yield reduction caused by heat stress during grain filling. NWJ-B treatment increased the sucrose content and sucrose phosphate synthase (SPS) activity of the flag leaves under heat stress during grain filling, which increased the ability of the plants to convert post-anthesis photoassimilates into sucrose, providing a basis for the accumulation of sucrose in the grains. Meanwhile, NWJ-B treatment increased the ability of the plants to assimilate and utilize nitrogen by increasing the nitrogen content and activity of nitrate reductase (NR) and glutamine synthetase (GS) of the flag leaves under heat stress during grain filling. Post-anthesis assimilation products and the activities of the enzymes related to carbon and nitrogen metabolism in wheat plants subjected to night warming treatments maintained at a higher level, which promoted the formation and conversion of proteins and starches in the grains at the late growth stages. Night warming treatments from the jointing to booting stage effectively improved post-anthesis physiological activity and plant productivity, which reduced yield loss caused by heat stress during grain filling.
•Night warming priming at early growth stages increased the photosynthetic assimilation capacity of the wheat.•Night warming priming at early growth stages also increased the ability of wheat to accumulate and transfer nitrogen under heat stress during grain filling.•Night warming priming from the jointing to booting stage showed the highest impact.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Low-molecular-weight glutenin subunit (LMW-GS) Glu-B3 plays an important role in the processing quality of the wheat used to make bread and noodles. A total of 214 accessions of common wheat ...(Triticum aestivum L.) comprising both landraces and improved cultivars collected from all the three growing zones in China were tested for ten alleles using 10 allele-specific PCR markers at the Glu-B3 locus. The frequency of the 'I' allele (20.6%) was greater than those of the other alleles. The 'I' allele was found in 18.7% of landraces and 23.8% of improved cultivars. The alleles, from most to least common, were 'I'>'a'>'d'>'g'>'f'>'b'>'e'>'c'>'j'>'h.' In the spring wheat zone, the Glu-B3 alleles were mainly 'g' and 'i,' but in the winter wheat zone, they were mainly 'a' and 'i.' The 'h' allele was only found in the spring wheat zone, but the 'a' and 'c' alleles were found in small proportions in the spring wheat and spring-winter wheat zones. The frequency of the 'I' allele was more than twice that of the b allele (9.3%). Because the 'b' allele has a more pronounced effect on gluten strength, varieties with the 'b' allele can be considered suitable for the breeding of new, highquality cultivars.
Global warming is asymmetric, with the increase in temperature at night being greater than that during the day. The objectives of this study were to assess the effects of night warming during ...different growth stages on the wheat grain yield, dry matter accumulation and distribution, photosynthetic characteristics, and enzymes related to sucrose metabolism. For that, field experiments with passive night warming were conducted using local spring type cultivars ‘Yangmai 18′ and ‘Sumai 188′ and semi-winter type cultivars ‘Yannong 19′ and ‘Annong 0711′ in two growing seasons in the Yangtze River Basin of China (average night time temperature increases of 1.45 °C and 1.56 °C for 2019–2020 and 2020–2021, respectively). The cultivars were exposed to night warming between four different growth stages (tillering to jointing NWT-J, jointing to booting NWJ-B, and booting to anthesis NWB-A) after 50% of plants had attained the treatment-start stage (tillering: Zadoks growth stage 21, main shoot and one tiller; jointing: Zadoks growth stage 31, the 1st node was detectable; booting: Zadoks growth stage 41, flag leaf sheath extension stage; anthesis: Zadoks growth stage 60, the beginning of pollination). Plants grown under ambient conditions were considered as the control (NN). Treatment NWT-J increased dry matter accumulation in flag leaves and spikes at anthesis and maturity, ultimately benefiting the yield, and the increase was higher in the semi-winter type cultivars. NWT-J increased not only the chlorophyll content, photosynthetic traits (net photosynthetic rate, stomatal conductance, and transpiration rate), and the activities of the maximum efficiency of PSII photochemistry under dark-adapted wheat flag leaves at the grain-filling stage (14 days after anthesis) but also the activities of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), fructose-1,6-bisphosphatase (FBPase), and glycolate oxidase (GOX), and thus improved the photosynthetic capacity of wheat flag leaves and facilitating photosynthate accumulation. NWT-J also increased sucrose-phosphate synthase activity in flag leaves at the grain-filling stage, which could improve sucrose content. Collectively, early vegetative night warming (warming during tillering-jointing) improved the photosynthetic capacity of the flag leaves during the grain-filling stage and promoted the post-anthesis accumulation of dry matter and the transfer of dry matter to the grains, which ultimately benefited the yield.
•Night warming from tillering to jointing showed most significant effect on yield.•Warming was more effective for semi-winter wheat than spring wheat cultivars.•Semi-winter wheat cultivars maintained a high photosynthetic capacity.•Night warming increased sucrose biosynthesis in leaves and the supply of sources.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Key message
A stripe rust resistance gene
YrZM175
in Chinese wheat cultivar Zhongmai 175 was mapped to a genomic interval of 636.4 kb on chromosome arm 2AL, and a candidate gene was predicted.
Stripe ...rust, caused by
Puccinia striiformis
f. sp.
tritici
(PST), is a worldwide wheat disease that causes large losses in production. Fine mapping and cloning of resistance genes are important for accurate marker-assisted breeding. Here, we report the fine mapping and candidate gene analysis of stripe rust resistance gene
YrZM175
in a Chinese wheat cultivar Zhongmai 175. Fifteen F
1
, 7,325 F
2
plants and 117 F
2:3
lines derived from cross Avocet S/Zhongmai 175 were inoculated with PST race CYR32 at the seedling stage in a greenhouse, and F
2:3
lines were also evaluated for stripe rust reaction in the field using mixed PST races. Bulked segregant RNA-seq (BSR-seq) analyses revealed 13 SNPs in the region 762.50–768.52 Mb on chromosome arm 2AL. By genome mining, we identified SNPs and InDels between the parents and contrasting bulks and mapped
YrZM175
to a 0.72-cM, 636.4-kb interval spanned by
YrZM175-InD1
and
YrZM175-InD2
(763,452,916–764,089,317 bp) including two putative disease resistance genes based on IWGSC RefSeq v1.0. Collinearity analysis indicated similar target genomic intervals in Chinese Spring,
Aegilops tauschii
(2D: 647.7–650.5 Mb),
Triticum urartu
(2A: 750.7–752.3 Mb),
Triticum dicoccoides
(2A: 771.0–774.5 Mb),
Triticum turgidum
(2B: 784.7–788.2 Mb), and
Triticum aestivum
cv. Aikang 58 (2A: 776.3–778.9 Mb) and Jagger (2A: 789.3–791.7 Mb). Through collinearity analysis, sequence alignments of resistant and susceptible parents and gene expression level analysis, we predicted
TRITD2Bv1G264480
from
Triticum turgidum
to be a candidate gene for map-based cloning of
YrZM175
. A gene-specific marker for
TRITD2Bv1G264480
co-segregated with the resistance gene. Molecular marker analysis and stripe rust response data revealed that
YrZM175
was different from genes
Yr1
,
Yr17
,
Yr32,
and
YrJ22
located on chromosome 2A. Fine mapping of
YrZM175
lays a solid foundation for functional gene analysis and marker-assisted selection for improved stripe rust resistance in wheat.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Key message
Ten stable loci for freezing tolerance (FT) in wheat were detected by genome-wide association analysis. The putative candidate gene
TaRPM1-7BL
underlying the major locus
QFT.ahau-7B.2
was ...identified and validated.
Frost damage restricts wheat growth, development, and geographical distribution. However, the genetic mechanism of freezing tolerance (FT) remains unclear. Here, we evaluated FT phenotypes of 245 wheat varieties and lines, and genotyped them using a Wheat 90 K array. The association analysis showed that ten stable loci were significantly associated with FT (
P
< 1 × 10
–4
), and explained 6.45–26.33% of the phenotypic variation. In particular, the major locus
QFT.ahau-7B.2
was consistently related to all nine sets of FT phenotypic data. Based on five cleaved amplified polymorphic sequence (CAPS) markers closely linked to
QFT.ahau-7B.2
, we narrowed down the target region to the 570.67–571.16 Mb interval (0.49 Mb) on chromosome 7B, in which four candidate genes were annotated. Of these, only
TaRPM1-7BL
exhibited consistent differential expression after low temperature treatment between freezing-tolerant and freezing-sensitive varieties. The results of cloning and whole-exome capture sequencing indicated that there were two main haplotypes for
TaRPM1-7BL
, including freezing-tolerant
Hap1
and freezing-sensitive
Hap2
. Based on the representative SNP (+1956, A/G), leading to an amino acid change in the NBS domain, a CAPS marker (
CAPS-TaRPM1-7BL
) was developed and validated in 431 wheat varieties (including the above 245 materials) and 318 F
2
lines derived from the cross of ‘Annong 9267’ (freezing-tolerant) × ‘Yumai 9’ (freezing-sensitive). Subsequently, the
TaRPM1-7BL
gene was silenced in ‘Yumai 9’ by virus-induced gene silencing (VIGS), and these silenced wheat seedlings exhibited enhanced FT phenotypes, suggesting that
TaRPM1-7BL
negatively regulates FT. These findings are valuable for understanding the complex genetic basis of FT in wheat.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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