scholarly journals WAPO-A1 is the causal gene of the 7AL QTL for spikelet number per spike in wheat

2021 ◽  
Author(s):  
Saarah Kuzay ◽  
Huiqiong Lin ◽  
Chengxia Li ◽  
Shisheng Chen ◽  
Daniel Woods ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Apical Region ◽  
Genome Wide Association Studies ◽  
Causal Gene ◽  
Spikelet Number ◽  
Grain Number Per Spike ◽  
A Genome ◽  
Wide Range ◽  
Spikelet Number Per Spike

Improving our understanding of the genes regulating grain yield can contribute to the development of more productive wheat varieties. Previously, a highly significant QTL affecting spikelet number per spike (SNS), grain number per spike (GNS) and grain yield was detected on chromosome arm 7AL in multiple genome-wide association studies. Using a high?resolution genetic map, we established that the A-genome homeolog of WHEAT ORTHOLOG OF APO1 ( WAPO-A1 ) was a leading candidate gene for this QTL. Using mutants and transgenic plants, we demonstrate in this study that WAPO-A1 is the causal gene underpinning this QTL. Loss-of-function mutants wapo-A1 and wapo-B1 showed reduced SNS in tetraploid wheat, and the effect was exacerbated in wapo1 combining both mutations. By contrast, spikes of transgenic wheat plants carrying extra copies of WAPO-A1 driven by its native promoter had higher SNS, a more compact spike apical region and a smaller terminal spikelet than the wild type. Taken together, these results indicate that WAPO1 affects SNS by regulating the timing of terminal spikelet formation. Both transgenic and wapo1 mutant plants showed a wide range of floral abnormalities, indicating additional roles of WAPO1 on wheat floral development. Previously, we found three widespread haplotypes in the QTL region (H1, H2 and H3), each associated with particular WAPO-A1 alleles. Integrating results from this study and previous findings, we show that the WAPO-A1 allele in the H1 haplotype (115-bp deletion in the promoter) is expressed at significantly lower levels in the developing spikes than the alleles in the H2 and H3 haplotypes, resulting in reduced SNS. Field experiments also showed that the H2 haplotype is associated with the strongest effects in increasing SNS and GNS (H2>H3>H1). The H2 haplotype is already present in most modern common wheats, so it might be particularly useful in durum wheat where H2 is rare.

scholarly journals WAPO-A1 is the causal gene of the 7AL QTL for spikelet number per spike in wheat

PLoS Genetics ◽  
2022 ◽  
Vol 18 (1) ◽  
pp. e1009747
Author(s):  
Saarah Kuzay ◽  
Huiqiong Lin ◽  
Chengxia Li ◽  
Shisheng Chen ◽  
Daniel P. Woods ◽  
...  
Keyword(s):  
Grain Yield ◽  
Apical Region ◽  
Genome Wide Association Studies ◽  
Causal Gene ◽  
Spikelet Number ◽  
Wheat Varieties ◽  
Grain Number Per Spike ◽  
A Genome ◽  
Wide Range ◽  
Spikelet Number Per Spike

Improving our understanding of the genes regulating grain yield can contribute to the development of more productive wheat varieties. Previously, a highly significant QTL affecting spikelet number per spike (SNS), grain number per spike (GNS) and grain yield was detected on chromosome arm 7AL in multiple genome-wide association studies. Using a high-resolution genetic map, we established that the A-genome homeolog of WHEAT ORTHOLOG OF APO1 (WAPO-A1) was a leading candidate gene for this QTL. Using mutants and transgenic plants, we demonstrate in this study that WAPO-A1 is the causal gene underpinning this QTL. Loss-of-function mutants wapo-A1 and wapo-B1 showed reduced SNS in tetraploid wheat, and the effect was exacerbated in wapo1 combining both mutations. By contrast, spikes of transgenic wheat plants carrying extra copies of WAPO-A1 driven by its native promoter had higher SNS, a more compact spike apical region and a smaller terminal spikelet than the wild type. Taken together, these results indicate that WAPO1 affects SNS by regulating the timing of terminal spikelet formation. Both transgenic and wapo1 mutant plants showed a wide range of floral abnormalities, indicating additional roles of WAPO1 on wheat floral development. Previously, we found three widespread haplotypes in the QTL region (H1, H2 and H3), each associated with particular WAPO-A1 alleles. Results from this and our previous study, show that the WAPO-A1 allele in the H1 haplotype (115-bp deletion in the promoter) is expressed at significantly lower levels in the developing spikes than the alleles in the H2 and H3 haplotypes, resulting in reduced SNS. Field experiments also showed that the H2 haplotype is associated with the strongest effects in increasing SNS and GNS (H2>H3>H1). The H2 haplotype is already present in most modern common wheat varieties but is rare in durum wheat, where it might be particularly useful to improve grain yield.

scholarly journals Identification and Validation of a Novel Locus Controlling Spikelet Number in Bread Wheat (Triticum aestivum L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Tao Li ◽  
Guangbing Deng ◽  
Yanyan Tang ◽  
Yan Su ◽  
Jinhui Wang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Genetic Map ◽  
Molecular Mechanisms ◽  
Limit Of Detection ◽  
Expression Patterns ◽  
Snp Array ◽  
Phenotypic Variance ◽  
Spikelet Number ◽  
Grain Number Per Spike ◽  
Spikelet Number Per Spike

Spikelet number is an important target trait for wheat yield improvement. Thus, the identification and verification of novel quantitative trait locus (QTL)/genes controlling spikelet number are essential for dissecting the underlying molecular mechanisms and hence for improving grain yield. In the present study, we constructed a high-density genetic map for the Kechengmai1/Chuanmai42 doubled haploid (DH) population using 13,068 single-nucleotide polymorphism (SNP) markers from the Wheat 55K SNP array. A comparison between the genetic and physical maps indicated high consistence of the marker orders. Based on this genetic map, a total of 27 QTLs associated with total spikelet number per spike (TSN) and fertile spikelet number per spike (FSN) were detected on chromosomes 1B, 1D, 2B, 2D, 3D, 4A, 4D, 5A, 5B, 5D, 6A, 6B, and 7D in five environments. Among them, five QTLs on chromosome 2D, 3D, 5A, and 7D were detected in multiple environments and combined QTL analysis, explaining the phenotypic variance ranging from 3.64% to 23.28%. Particularly, QTsn/Fsn.cib-3D for TSN and FSN [phenotypic variation explained (PVE) = 5.97–23.28%, limit of detection (LOD) = 3.73–18.51] is probably a novel locus and located in a 4.5-cM interval on chromosome arm 3DL flanking by the markers AX-110914105 and AX-109429351. This QTL was further validated in other two populations with different genetic backgrounds using the closely linked Kompetitive Allele-Specific PCR (KASP) marker KASP_AX-110914105. The results indicated that QTsn/Fsn.cib-3D significantly increased the TSN (5.56–7.96%) and FSN (5.13–9.35%), which were significantly correlated with grain number per spike (GNS). We also preliminary analyzed the candidate genes within this locus by sequence similarity, spatial expression patterns, and collinearity analysis. These results provide solid foundation for future fine mapping and cloning of QTsn/Fsn.cib-3D. The developed and validated KASP markers could be utilized in molecular breeding aiming to increase the grain yield in wheat.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Evidence for improved pollen viability as the mechanism for film antitranspirant mitigation of drought damage to wheat yield

2016 ◽  
Vol 67 (2) ◽  
pp. 137 ◽  
Author(s):  
Minuka M. Weerasinghe ◽  
Peter S. Kettlewell ◽  
Ivan G. Grove ◽  
Martin C. Hare
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Pollen Viability ◽  
Wheat Yield ◽  
Spray Application ◽  
Grain Number ◽  
Climatic Zones ◽  
Boot Stage ◽  
Wide Range ◽  
Drought Damage

Application of film antitranspirant to wheat during late stem extension reduces drought damage to yield, but the mechanism is unknown. Field experiments under rain shelters were conducted over 3 years to test the hypothesis that film antitranspirant applied before meiosis alleviates drought-induced losses of pollen viability, grain number and yield. The film antitranspirant di-1-p-menthene was applied at third-node stage, and meiosis occurred at the early boot stage, with a range of 11–16 days after spray application in different years. Irrigated, unsprayed plots were included under the rain-shelters, and pollen viability, measured in 2 years in these plots, averaged 95.3%. Drought reduced pollen viability to 80.1% in unirrigated, unsprayed plots, but only to 88.6% in unirrigated plots treated with film antitranspirant. Grain number and yield of irrigated plots, measured in all years, were 16 529 m–2 and 9.55 t ha–1, respectively, on average. These were reduced by drought to 11 410 m–2 and 6.31 t ha–1 in unirrigated, unsprayed plots, but only to 12 878 m–2 and 6.97 t ha–1 in unirrigated plots treated with film antitranspirant. Thus compared with unirrigated, unsprayed plots, antitranspirant gave a grain yield benefit of 0.66 t ha–1. Further work is needed to validate the pollen viability mechanism in different climatic zones and with a wide range of cultivars.

Variation in south Asian wheat germplasm for seedling drought tolerance traits

2009 ◽  
Vol 7 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Umesh R. Rosyara ◽  
Amrit A. Ghimire ◽  
Sushil Subedi ◽  
Ram C. Sharma
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Dwarfing Genes ◽  
Seedling Vigour ◽  
Coleoptile Length ◽  
Wide Range ◽  
Dry Conditions ◽  
Breeding Programmes ◽  
Positive Correlations

Higher seedling vigour and greater coleoptile length are important for early establishment of wheat crops and subsequently higher grain yield in many dry environments. Seedling vigour includes those seed properties that determine the potential for rapid, uniform emergence and development of normal seedlings under a wide range of field conditions. Genotypes with the widely used gibberellic acid (GA)-insensitive dwarfing genes Rht-B1b and Rht-D1b have good partitioning and grain yield under optimal conditions, but may perform poorly under stressed conditions due to poor crop establishment. Breeding programmes are in search of GA-sensitive dwarfing genes that do not affect seedling vigour under dry conditions. This study evaluated 40 genotypes currently used in wheat breeding programmes of south Asia for seedling vigour-related traits in greenhouse and field experiments during 2006–2007 at IAAS, Rampur, Nepal. Wide variation in coleoptile length, seedling vigour, as well as sensitivity to GA was observed. Among the genotypes studied, there were positive correlations among coleoptile length, leaf width and plant height. Genotypes, SW89-5193, SW89-5422/NL251 and SW89-5422, were found to have longer coleoptile, higher seedling vigour and response to GA application. This shows a promise for their further applications in the breeding programmes.

Effect of time sowing and cultivar on the development and grain yield of irrigated wheat in the Macquarie Valley, New South Wales

1992 ◽  
Vol 32 (3) ◽  
pp. 345 ◽  
Author(s):  
JL Cooper
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Moisture Stress ◽  
Frost Damage ◽  
Yield Reduction ◽  
Detectable Effect ◽  
South Wales ◽  
Wide Range

Field experiments over 2 seasons in the Macquarie Valley of central New South Wales compared yields under irrigation of 5 wheat varieties with a wide range of maturities sown from 8 April to 27 August.Early maturity wheats (Yecora and Avocet) sown prior to 6 May suffered frost damage, while the winter wheats (WW33G and Burgas) sown after 29 July were not fully vernalised and most tillers failed to produce heads. There was a curvilinear relation between time of sowing and grain yield. Excluding the treatments which suffered frost damage, the earliest time of sowing (8 April) produced the highest yield, with a 6.4% yield reduction between 8 April and 8 May. The yield reduction increased with later sowing date: 13.3, 19.3, and 26.5% during May, June, and July. Anthesis in mid September produced the highest yields for all varieties. Treatments which flowered earlier than mid September suffered frost damage. For each day later than 15 September that anthesis occurred, the mean yield fell by 1.3% or about 68 kg/ha.day. Date of anthesis had no detectable effect on the rate of individual grain growth (1.3 mg/grain.day), but the later anthesis occurred, the shorter the duration of grain development and the lower the final grain weight. Rising temperatures, not moisture stress, seems to be the factor causing the decline in yield with late sowing. This experiment was irrigated to eliminate moisture stress but the decline in yield was similar to that reported for dryland crops.

scholarly journals TaAPO-A1, an ortholog of rice ABERRANT PANICLE ORGANIZATION 1, is associated with total spikelet number per spike in elite European hexaploid winter wheat (Triticum aestivum L.) varieties

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Quddoos H. Muqaddasi ◽  
Jonathan Brassac ◽  
Ravi Koppolu ◽  
Jörg Plieske ◽  
Martin W. Ganal ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Association Studies ◽  
Physical Region ◽  
Triticum Aestivum L ◽  
Snp Markers ◽  
Genome Wide Association Studies ◽  
Terrestrial Plants ◽  
Spikelet Number ◽  
Wheat Varieties ◽  
Wide Range

Abstract We dissected the genetic basis of total spikelet number (TSN) along with other traits, viz. spike length (SL) and flowering time (FT) in a panel of 518 elite European winter wheat varieties. Genome-wide association studies (GWAS) based on 39,908 SNP markers revealed highly significant quantitative trait loci (QTL) for TSN on chromosomes 2D, 7A, and 7B, for SL on 5A, and FT on 2D, with 2D-QTL being the functional marker for the gene Ppd-D1. The physical region of the 7A-QTL for TSN revealed the presence of a wheat ortholog (TaAPO-A1) to APO1–a rice gene that positively controls the spikelet number on the panicles. Interspecific analyses of the TaAPO-A1 orthologs showed that it is a highly conserved gene important for floral development and present in a wide range of terrestrial plants. Intraspecific studies of the TaAPO-A1 across wheat genotypes revealed a polymorphism in the conserved F-box domain, defining two haplotypes. A KASP marker developed on the polymorphic site showed a highly significant association of TaAPO-A1 with TSN, explaining 23.2% of the total genotypic variance. Also, the TaAPO-A1 alleles showed weak but significant differences for SL and grain yield. Our results demonstrate the importance of wheat sequence resources to identify candidate genes for important traits based on genetic analyses.

Drought resistance in spring wheat cultivars. I. Grain yield responses

1978 ◽  
Vol 29 (5) ◽  
pp. 897 ◽  
Author(s):  
RA Fischer ◽  
R Maurer
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Water Status ◽  
Cultivar Differences ◽  
Yield Potential ◽  
Severe Drought ◽  
Yield Data ◽  
Wide Range ◽  
The Mean ◽  
Yield Responses

With a view to understanding the basis of cultivar differences in yield under drought, a wide range of cereal cultivars representing durum wheats (Triticum turgidum L.), triticales (X Tritosecale Wittmack), barleys (Hordeum vulgare), and especially tall and dwarf bread wheats (T. aestivum L.) were studied in field experiments in north-western Mexico over three seasons. Drought was created in this rain-free environment by permanently terminating irrigation at various stages before anthesis. Control treatments were well watered throughout the growing period. Detailed measurements of plant water status, leaf area and dry matter production, anthesis date, yield components and grain yield were made. This paper presents primarily the grain yield data. Drought levels were such that the mean yield of all cultivars under drought ranged from 37 to 86% of control yield, corresponding to irrigation cut-offs varying from 69 days before mean anthesis date to only 10 days before. In each experiment the grain yield under drought showed highly significant cultivar differences, which appeared consistent between years. Yields were adjusted for drought escape by using a correction factor which ranged from 2.9 to 8.5 g/m2 per day advance in flowering, being greater in experiments with less severe drought. The demonstration of linear relationships between cultivar yield and drought intensity, as indicated by the mean yield of some or all cultivars, prompted the consideration of cultivar yield under drought as the function of yield potential (Yp, yield without drought), drought susceptibility index (S), and intensity of drought. The cultivar groups showing lowest S values (most droughtresistant) were tall bread wheats and barleys; dwarf bread wheats were intermediate, and durum wheats and triticales were the most susceptible. However, because dwarf wheats have a higher yield potential (Yp) than tall bread wheats, it is suggested that, as a group, tall bread wheats would outyield dwarf wheats only under very severe drought. Also there was considerable within-group variability of S and Yp. Cultivar S values were consistent across experiments. Yield responses of tall and dwarf bread wheat groups obtained in these experiments agreed with those seen in extensive international trials under dryland conditions.

Corrigenda - Predicting yield responsiveness and phosphorus fertilizer requirements of soybeans from soil tests

Soil Research ◽  
1990 ◽  
Vol 28 (3) ◽  
pp. 399
Author(s):  
PW Moody ◽  
T Dickson ◽  
JC Dwyer ◽  
BL Compton
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Single Point ◽  
Fertilizer Application ◽  
Soil P ◽  
Wide Range ◽  
P Fertilizer ◽  
Curvature Coefficient ◽  
Sorption Index ◽  
Buffer Capacities

Field experiments with rain-fed Bragg soybeans (Glycine max) were carried out at 30 sites in central south-eastern Queensland over six years. The sites covered a wide range of soil types and P buffer capacities. Several rates of P fertilizer were band-applied in 0.9 m rows at planting. Relative grain yield at each site was correlated with 0.5 M NaHC03 extractable (PB) and 0.01 M CaCl2 extractable (PC) phosphorus. Mitscherlich equations of best fit indicated that PC was better correlated (r2 = 0.85) with relative grain yield than PB (r2 = 0.59). At 90% maximum grain yield, the 'critical' PC value was 43 �g P kg-1. The Mitscherlich curvature coefficient, c, was correlated (r2 = 0.49, P < 0.001) with the amount of P fertilizer required for 90% maximum grain yield, but not with soil P buffer capacity, as measured by a single point sorption index (r2 = 0.06). Factors other than the P sorbing ability of the soil were affecting the curvature coefficient, but could not be identified in this work. PC was sufficiently well correlated (r2 = 0.66, P < 0.001) with P fertilizer requirements to have use as a predictor of these requirements. The findings are compared with those obtained for other crops and P fertilizer application methods.

Predicting yield responsiveness and phosphorus fertilizer requirements of soybeans from soil tests

Soil Research ◽  
1990 ◽  
Vol 28 (3) ◽  
pp. 399
Author(s):  
PW Moody ◽  
T Dickson ◽  
JC Dwyer ◽  
BL Compton
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Single Point ◽  
Fertilizer Application ◽  
Soil P ◽  
Wide Range ◽  
P Fertilizer ◽  
Curvature Coefficient ◽  
Sorption Index ◽  
Buffer Capacities

Field experiments with rain-fed Bragg soybeans (Glycine max) were carried out at 30 sites in central south-eastern Queensland over six years. The sites covered a wide range of soil types and P buffer capacities. Several rates of P fertilizer were band-applied in 0.9 m rows at planting. Relative grain yield at each site was correlated with 0.5 M NaHC03 extractable (PB) and 0.01 M CaCl2 extractable (PC) phosphorus. Mitscherlich equations of best fit indicated that PC was better correlated (r2 = 0.85) with relative grain yield than PB (r2 = 0.59). At 90% maximum grain yield, the 'critical' PC value was 43 �g P kg-1. The Mitscherlich curvature coefficient, c, was correlated (r2 = 0.49, P < 0.001) with the amount of P fertilizer required for 90% maximum grain yield, but not with soil P buffer capacity, as measured by a single point sorption index (r2 = 0.06). Factors other than the P sorbing ability of the soil were affecting the curvature coefficient, but could not be identified in this work. PC was sufficiently well correlated (r2 = 0.66, P < 0.001) with P fertilizer requirements to have use as a predictor of these requirements. The findings are compared with those obtained for other crops and P fertilizer application methods.

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