Wheat Region Research Articles

A second generation capture panel for cost-effective sequencing of genome regulatory regions in wheat and relatives

A second generation capture panel for cost-effective sequencing of genome regulatory regions in wheat and relatives

A second generation capture panel for cost-effective sequencing of genome regulatory regions in wheat and relatives

A second generation capture panel for cost-effective sequencing of genome regulatory regions in wheat and relatives

Identification of genomic regions of wheat associated with grain Fe and Zn content under drought and heat stress using genome-wide association study.

Wheat is the staple food crop of global importance for its grain nutrient quality. Grain iron and zinc content of the wheat grain is an important quantitatively inherited trait that is influenced by the environmental factors such as drought and heat stress. Phenotypic evaluation of 295 advanced breeding lines from the wheat stress breeding program of IARI was carried out under timely sown irrigated (IR), restricted irrigated, and late-sown conditions at New Delhi during the cropping season of 2020-21, and grain iron (GFeC) and zinc (GZnC) contents were estimated from both control and treatments. A statistically significant increase in GFeC and GZnC was observed under stress conditions compared to that of the control. Genotyping was carried out with the SNPs from the 35K Axiom Breeder's array, and marker-trait association was identified by GWAS analysis. Of the 23 MTAs identified, seven were linked with GFeC and sixteen were linked with GZnC. In silico analysis revealed a few important transcripts involved in various plant metabolism, growth, and development activities such as auxin response factor, root UVB sensitive proteins, potassium transporter, glycosyl transferase, COBRA, and F-box-like domain. The identified MTAs can be used for molecular breeding after validation and also for rapid development of micronutrient-rich varieties of wheat to mitigate hidden hunger.

Genome-wide association, RNA-seq and iTRAQ analyses identify candidate genes controlling radicle length of wheat.

The radicle, present in the embryo of a seed, is the first root to emerge at germination, and its rapid growth is essential for establishment and survival of the seedling. However, there are few studies on the critical mechanisms underlying radicle and then radicle length in wheat seedlings, despite its importance as a food crop throughout the world. In the present study, 196 wheat accessions from the Huanghuai Wheat Region were screened to measure radicle length under 4 hydroponic culture environments over 3 years. Different expression genes and proteins (DEGs/DEPs) between accessions with extremely long [Yunong 949 (WRL1), Zhongyu 9,302 (WRL2)] and short roots [Yunong 201 (WRS1), Beijing 841 (WRS2)] were identified in 12 sets of root tissue samples by RNA-seq and iTRAQ (Isobaric tags for relative and absolute quantification). Phenotypic results showed that the elongation zone was significantly longer in root accessions with long roots compared to the short-rooted accessions. A genome-wide association study (GWAS) identified four stable chromosomal regions significantly associated with radicle length, among which 1A, 4A, and 7A chromosomes regions explained 7.17% to12.93% of the phenotypic variation. The omics studies identified the expression patterns of 24 DEGs/DEPs changed at both the transcriptional and protein levels. These DEGs/DEPs were mainly involved in carbon fixation in photosynthetic organisms, photosynthesis and phenylpropanoid biosynthesis pathways. TraesCS1A02G104100 and TraesCS2B02G519100 were involved in the biosynthesis of tricin-lignins in cell walls and may affect the extension of cell walls in the radicle elongation zone. A combination of GWAS and RNA-seq analyses revealed 19 DEGs with expression changes in the four accessions, among which, TraesCS1A02G422700 (a cysteine-rich receptor-like protein kinase 6, CRK6) also showed upregulation in the comparison group by RNA-seq, iTRAQ, and qRT-PCR. BSMV-mediated gene silencing also showed that TaCRK6 improves root development in wheat. Our data suggest that TaCRK6 is a candidate gene regulating radicle length in wheat.

Evaluation of wheat (Triticum aestivum L.) genotypes for spot blotch (Bipolaris sorokiniana Sacc) resistance in terai condition of Nepal

Spot blotch caused by Bipolaris sorokiniana is a major disease of wheat in warm and humid regions of Nepal. The fungus has a worldwide distribution but as a pathogen, it is the most aggressive under the conditions of high relative humidity and temperature associated with the low fertility of soils in Nepal. The yield loss due to the disease is very significant in Nepal. This experiment was conducted to identify the genotypes having a good level of resistance against spot blotch. The experiment set was received from CIMMYT comprises 52 genotypes and arranged in alpha lattice design with two replications in 2017/18 at National Wheat Research Program, Bhairahawa, Nepal, and Regional Agricultural Research Station, Parwanipur, Bara, Nepal. Each plot size was 8 rows of 2 meters long. Three times disease scoring was done in the double-digit method and calculated the Area under the disease progress curve (AUDPC). Other data were analyzed by using R software (4.2.2). Heading days, days to maturity, plant height, number of grains per spike (NGPS), number of tillers per meter square (NTPM), mean AUDPC, thousand-grain weight (TGW), and grain yield were found highly significant. The genotype 8HLBSN47 was found the highest yielder (4996kg/ha) with a 304 mean AUDPC value. Seventeen genotypes (15.3%) found the lowest mean AUDPC, Penultimate leaf AUDPC, Flag leaf AUDPC, and the highest number of tillers per square meter, number of grains per spike, thousand-grain weight, and grain yield.

Performance of Wheat (Triticum aestivum L.) Genotypes for Spot Blotch (Bipolaris sorokiniana Sacc.) Resistance in Terai Condition of Nepal

Spot blotch caused by Bipolaris sorokiniana is a major disease of wheat in warm and humid regions of Nepal. The fungus has a worldwide distribution but as a pathogen, it is the most aggressive under the conditions of high relative humidity and temperature associated with the low fertility of soils in Nepal. The yield loss due to the disease is very significant in Nepal. This experiment was conducted to identify the genotypes having a good level of resistance against spot blotch. The experiment set was received from CIMMYT comprises 52 entries and arranged in alpha lattice design with two replications in 2017/18 at National Wheat Research Program, Bhairahawa, Nepal, and Regional Agricultural Research Station, Parwanipur, Bara, Nepal. Each plot size was 8 rows of 2 meters long. Three times disease scoring was done in the double-digit method and calculated the Area under the disease progress curve (AUDPC). Other data were analyzed by using R software (4.2.2). Heading days, days to maturity, plant height, number of grains per spike (NGPS), number of tillers per meter square (NTPM), mean AUDPC, thousand-grain weight (TGW), and grain yield were found highly significant. The genotype 8HLBSN47 was found the highest yielder (4996kg/ha) with a 304 mean AUDPC value. Seventeen genotypes (15.3%) found the lowest mean AUDPC, Penultimate leaf AUDPC, Flag leaf AUDPC, and the highest number of tillers per square meter, number of grains per spike, thousand-grain weight, and grain yield. Keywords: AUDPC, spot blotch, genotypes, HLBSN

Climate and management impacts on crop growth and evapotranspiration in the North China Plain based on long-term eddy covariance observation

Comprehensive understanding of how climate change and cropland management affect crop growth and water consumption is essential but unclear in the North China Plain (NCP) which is one of the major winter wheat and summer maize production regions. By combining an agro-hydrological model with 16-year eddy covariance observation, we quantified the impacts of climatic factors and key management (i.e., sowing date and irrigation) on the trend of key phenological stages, leaf area index (LAI), crop yield, evapotranspiration (ET), and water use efficiency (WUE) at a typical irrigated site in the NCP. We found that the advance of start and end of season was mainly caused by advanced sowing date and rising temperature which also shortened the reproductive phase; however, the growing season length (GSL) was remarkably shortened by advanced sowing date. Although LAI and yield of both crops were increasing, they were mainly negatively affected by rising temperature while slightly promoted by elevated CO2 concentration. LAI and yield of maize were also greatly improved by increasing radiation and irrigation, and wheat's growth was considerably hampered by excessive irrigation. Increasing ET was mainly ascribed to increasing radiation and decreasing humidity, but slightly inhibited by elevated CO2 concentration. Increasing WUE was mainly inhibited by the rising temperature and decreasing humidity while improved slightly by elevated CO2 concentration. Besides, we inferred that increase in LAI, yield, ET, and WUE of wheat is most likely to be attributed to the renewal of cultivars, the delay of key phenological stages, and prolongation of GSL for both crops was also possibly caused by the renewal of cultivars. Our study provided a first comprehensive insight into the long-term coupled variation of crop growth and evapotranspiration in this region.

Factors Influencing the Spatiotemporal Variability in the Irrigation Requirements of Winter Wheat in the North China Plain under Climate Change

The North China Plain is a major grain-producing area, but faces water scarcity, which directly threatens food security. The problem is more severe under climate change and the seasonal impact of climate change on winter wheat is different. Thus, it is of great importance to explore the spatiotemporal characteristics of irrigation requirements (IR) and the factors influencing IR in different growth periods of winter wheat, but it has not received much attention. Therefore, we used relative contribution, partial correlation and path analyses to assess the spatiotemporal characteristics of the IR and primary factors influencing the IR of winter wheat in various growing stages in the North China Plain. The results indicated that wind speed and net solar radiation showed a significant downward trend; no prominent trend was noted in IR (multiyear average, 302.3 mm). Throughout the growing season of winter wheat, IR increased gradually from the southern to northern extent of the North China Plain. The irrigation demand of winter wheat in stage P2 (green-up to heading) was the largest. Furthermore, the dominant drivers of IR in terms of spatial distribution and inter-annual variation were phenological period (Phe), effective precipitation (Pe) and relative humidity (RH); however, the degree of their effects varied across the growth stages and growing regions of winter wheat. Each factor exerted both direct and indirect effects on IR and Phe exhibited the strongest indirect effect on IR. The major factors contributing most to IR were Pe and RH in the P1 stage (sowing to green-up) and Phe, Pe and RH in the P2 and P3 (heading to maturity) stages. Pe and RH limited IR, whereas Phe promoted it. Our findings will help improve agricultural water management in the future.

Soil Carbon and Phosphorus after 40 Years of Contrasting Tillage and Straw Management in Dryland Wheat Production under Semi-Arid Temperate Climate

The effects of conservation strategies on soil organic carbon (SOC) and phosphorus (P) dynamics in dryland wheat under semi-arid temperate conditions are not well understood. This study quantified the effects of tillage and straw management on SOC concentrations and stocks and P fractions after 40 years of dryland wheat under a semi-arid temperate climate. The treatments were straw management (burned and not burned) combined with tillage methods (conventional tillage (CT), stubble mulch (SM), and no-tillage (NT)). Fertilizer nitrogen (N) and P were applied annually at 60 and 12.5 kg ha−1, respectively. The soils were sampled from 0–50, 50–200, 200–400, 400–600, 600–800, and 800–1000 mm depths, and analyzed using standard methods. The concentration of SOC was not affected by tillage and straw management, except in 200–400 mm where it was higher where the straw was burned rather than retained. The total C stock (0–1000 mm) was higher under NT with straw burning, CT with no burning, and SM, than NT with straw retention and CT with burning. In the topsoil, NT had significantly (p < 0.05) higher Bray 1 P, NaOH II Pi, and residual P than SM and CT, while burning straw increased Bray 1 P and NaHCO3 Pi concentrations. The findings imply that while the SOC concentration is not significantly affected by tillage, but is increased by burning in the subsoil only, the total C stock is improved by NT with burned straw, CT with straw retention, and SM, while the labile P fractions are increased by NT with burned straw, relative to CT with burned straw, in the semi-arid dryland wheat region.

Understanding the inventor team size: A view from “The Rice Theory”

AbstractThe inventor is a vital input in acquiring new technologies. Collaboration among inventors is an essential topic for scholars. Talhelm et al. proposed The Rice Theory, highlighting the cultural differences between rice and wheat regions. This paper explores the differences in inventor team size under rice and wheat cultures using invention patent data in China. The results of ordinary least square estimation and instrumental variable estimation indicate that the size of inventor teams under rice culture is significantly smaller than that under wheat culture by 0.558–0.721 persons. Using the Chinese Qinling–Huaihe line, this paper constructs a regression discontinuity (RD) design. The local average treatment effect estimation confirms the difference in rice and wheat cultures. Subsequently, we demonstrate the significant existence of this difference through lots of robustness checks. We try to explain the phenomenon from the perspective of “The Rice Theory” by arguing that inventors in rice regions may be more inclined to collaborate but with a smaller inventor team size. This paper demonstrates the cultural differences in the performance of inventor team size, informing our understanding of input in research and development (R&D) activities.

A novel naturally Phe206Tyr mutation confers tolerance to ALS-inhibiting herbicides in Alopecurus myosuroides

Herbicide-resistant weeds pose a serious threat to world food production. The rapid and widespread development of target-site based resistance limits the application of herbicides. Alopecurus myosuroides Huds. (blackgrass) has spread rapidly in winter wheat regions in China, and the field recommended dose of ALS herbicides no longer controls blackgrass populations in recent years. A highly resistant population TW18(R) was collected in 2018 from Shandong Province. Dose-response assays showed that the TW18 was resistant to mesosulfuron-methyl, flucarbazone-sodium, and imazethapyr, with resistance index values of 5.96, 6.1, and 4.09, respectively. DNA sequencing of the TW18 population revealed a Phe206Tyr (F206Y) mutation in the ALS, which was not yet reported. Blackgrass ALS gene with the F206Y mutation (R gene) was expressed in Arabidopsis and rice. Transgenic studies have shown that both Arabidopsis and rice expressing this R gene have resistance to imazethapyr. However, it did not confer resistance to tribenuron methyl and florasulam in transgenic Arabidopsis. This study showed that the F206Y substitution caused herbicide resistance in blackgrass. To our knowledge, this is the first-reported F206Y mutation of a weed species in the natural environment. Transgenic plants showed this functional site could be utilized to generate imazethapyr-resistant rice to control herbicide-resistant weed damage.

Heterosis prediction of wheat based on SNP genetic distance and combining ability

<p indent="0mm">Heterosis, as a means of increasing crop yield, has been used as part of long-term strategies to meet the demand for global food security. Molecular markers have been widely used to predict the outcome of crop heterosis. However, there is little research on genomic single-nucleotide polymorphism (SNP) prediction for heterosis in wheat (<italic>Triticum aestivum </italic>L.). In this study, we genotyped 30 wheat cultivars (lines) using wheat <sc>660 K</sc> SNP chip technology and constructed the hybrid population of 419 F₁ using diallel design. Yield component traits (YCT) in three environments, combining ability effect, and the genetic distance of <sc>660 K</sc> SNP array were used to predict heterosis. As expected, general commercial heterosis (CH), mid-parent heterosis (MPH), and high-parent heterosis (HPH) were observed in wheat YCT. The combining ability effect, here composed of the general combining ability (GCA) and special combining ability (SCA), was varied due to the parents or traits. For GCA, Bainong4199 had the smallest influence on plant height (PH), while BNS366 and CL0438 had the greatest influence on thousand kernel weight (TKW) and spike length (SL), respectively. Chinese spring showed the highest GCA on PH, spike number per plant (SNPP), and grain yield per plant (GYP), and SN055525 showed the highest GCA of spikelet number per spike (SNS), grain number per spike (GNS), and kernel weight per spike (KWPS). More importantly, SN055525, Chinese Spring, and CL0438 were found to be better restorer lines for male sterile lines BNS and BNS366. In addition, when BNS, BNS366, and Zhoumai18 in the Huanghuai wheat region were crossed with Yunnanmai and MR168 in the Southwest wheat region or foreign varieties Ciava and CL0442, SCA occurred more frequently for SNPP, SL, GNS, KWPS, and GYP. GCA and SCA showed a positive correlation with hybrid yield, CH, MPH, and HPH (<italic>P </italic>&lt; 0.01). Genotyping 30 parents with <sc>660 K</sc> chips showed the genetic distance of these SNPs to be positively correlated with GYP, GCA, and CH (<italic>P </italic>&lt; 0.01). The genetic distance of SNP was greater in superior combination, and consistent with the GCAs of parents, SCA and CH in 35.71% and 61.90% among the top 10% combinations, respectively. According to the clustering results of parental SNP, YCT, and GCA, these parents were clustered into three major groups. The cultivars from the Huanghuai wheat region clustered into groups A, B1, and C2; the cultivars from the Southwest wheat region clustered in groups B2 and C1; and foreign varieties clustered in group C2. Based on the genetic distance of SNP, combining ability, and superiority combination in the Huanghuai wheat region, we propose three wheat heterotic patterns: Huanghuai group B1/Southwest group B2, Huanghuai group B1/foreign group C2, and Huanghuai group C2/group B. The male sterile lines and restorer lines can be improved based on these heterotic groups of different wheat regions, which provide an important reference for parental selection of wheat hybrids and the production and use of hybrid wheat in the Huanghuai wheat region.

Virulence Phenotypes of the Wheat Leaf Rust Pathogen, Puccinia triticina, in the United States from 2018 to 2020.

Collections of wheat leaves infected with the leaf rust fungus, Puccinia triticina, were obtained from the southeastern states, the Ohio Valley, the Great Plains, and Washington in 2018, 2019, and 2020 to determine the prevalent virulence phenotypes in the wheat-growing regions of the United States. In the hard red winter wheat region of the southern and mid Great Plains, MNPSD and MPPSD were the two most common phenotypes in 2018 and 2019. In 2020, BBBQD with high virulence to durum wheat was the most common phenotype in the southern Great Plains. In the hard red spring wheat region of the northern Great Plains, MNPSD, MPPSD, MBDSD, and TBBGS were the predominant phenotypes. In the soft red winter wheat region of the southeastern states and Ohio Valley region, MBTNB, MCTNB, and MNPSD were the three most common phenotypes. Collections in Washington had phenotypes LBDSG, LCDSG, LCDJG, and MBDSB that were not found in any other region. Isolates with virulence to the leaf rust resistance (Lr) gene Lr11 were most frequent in the southeastern states and Ohio Valley regions. The frequency of isolates with virulence to the Lr39 gene was highest in the Great Plains region and frequency of isolates with virulence to the Lr21 gene was highest in the northern Great Plains region. Selection of virulence phenotypes by Lr genes in the different market classes of wheat, combined with the effects of clonal reproduction, overwintering in southern regions, and low migration between the Great Plains region and eastern wheat-producing regions, has maintained the different P. triticina populations in the United States.

Unravelling consensus genomic regions associated with quality traits in wheat using meta-analysis of quantitative trait loci.

Meta-analysis in wheat for three major quality traits identified 110 meta-QTL (MQTL) with reduced confidence interval (CI). Five GWAS validated MQTL (viz., 1A.1, 1B.2, 3B.4, 5B.2, and 6B.2), each involving more than 20 initial QTL and reduced CI (95%) (< 2cM), were selected for quality breeding programmes. Functional characterization including candidate gene mining and expression analysis discovered 44 high confidence candidate genes associated with quality traits. A meta-analysis of quantitative trait loci (QTL) associated with dough rheology properties, nutritional traits, and processing quality traits was conducted in wheat. For this purpose, as many as2458 QTL were collected from 50 interval mapping studies published during 2013-2020. Of the total QTL, 1126 QTL were projected onto the consensus map saturated with 249,603 markers which led to the identification of 110 meta-QTL (MQTL). These MQTL exhibited an 18.84-fold reduction in the average CI compared to the average CI of the initial QTL (ranging from 14.87 to 95.55cM with an average of 40.35cM). Of the 110, 108 MQTL were physically anchored to the wheat reference genome, including 51 MQTL verified with marker-trait associations (MTAs) reported from earlier genome-wide association studies. Candidate gene (CG) mining allowed the identification of 2533 unique gene models from the MQTL regions. In-silico expression analysis discovered 439 differentially expressed gene models with > 2 transcripts per million expressions in grains and related tissues, which also included 44 high-confidence CGs involved in the various cellular and biochemical processes related to quality traits. Nine functionally characterized wheat genes associated with grain protein content, high-molecular-weight glutenin, and starch synthase enzymes were also found to be co-localized with some of the MQTL. Synteny analysis between wheat and rice MQTL regions identified 23 wheat MQTL syntenic to 16 rice MQTL associated with quality traits. Furthermore, 64 wheat orthologues of 30 known rice genes were detected in 44 MQTL regions. Markers flanking the MQTL identified in the present study can be used for marker-assisted breeding and as fixed effects in the genomic selection models for improving the prediction accuracy during quality breeding. Wheat orthologues of rice genes and other CGs available from MQTLs can be promising targets for further functional validation and to better understand the molecular mechanism underlying the quality traits in wheat.

A Bio-Economic Model for Improving Irrigated Durum Wheat Performance and Regional Profits under Mediterranean Conditions

Irrigated durum wheat is a staple food crop that occupies important areas in Tunisia. However, its performance remains weak, with an average national yield of no more than 3.6 tons ha−1 and low profitability. Overall, on-farm wheat production will need to increase considerably to meet future demand and ensure minimum profitability for farmers. To this end, this study aims to identify the main levers for improving durum wheat crop performance. For this purpose, we have developed a regional bio-economic model by linking a biophysical model (CROPSYST) with an economic optimization model (MORBIT). CROPSYST was used to establish a database with a view to determining the relationships between farming practices, durum wheat yields, and water productivity within a context of high climate variability. The database was then integrated into a MORBIT model that analyzed the effects of farming practices on durum wheat performance and regional profits. Three scenarios related to irrigation control and the increase in durum wheat prices were developed. The results showed that reconciling irrigation practices with economic policies is the best alternative to improve durum wheat performance and increase profits at a regional level.

Characteristics of lodging resistance of high-yield winter wheat as affected by nitrogen rate and irrigation managements

High yields of wheat are mainly obtained through a high level of nitrogen and irrigation supplementation. However, excessive nitrogen and irrigation supplication increase the risk of lodging. The main objectives of this work were to clarify the capacity of lodging resistance of wheat in response to nitrogen and irrigation, as well as to explore the effective ways of improving lodging resistance in a high-yield wheat cultivar. In this study, field experiments were conducted in the 2015–2016 and 2016–2017 growing seasons. A wheat cultivar Jimai 22 (JM22), which is widely planted in the northern of Huang-Huai winter wheat region, was grown at Tai'an, Shandong Province, under three nitrogen rates and four irrigation treatments. The lodging risk was increased with increased nitrogen rate, as indicated by increasing lodging index (LI) and lodging rate across both growing seasons. With nitrogen increasing, the plant height, the basal internode length and the center of gravity height, which were positively correlated with LI, increased significantly. While the density of the basal 2nd internode (for culm and leaf sheath) and cell wall component contents, which were negatively correlated with LI, decreased conspicuous along with nitrogen increased. Increasing irrigation supplementation increased the 2nd internode culm wall thickness, breaking strength and leaf sheath density within limits which increased stem strength. Among the treatments, nitrogen application at a rate of 240 kg ha–1 and irrigation application at 600 m3 ha–1 at both the jointing and anthesis stages resulted in the highest yield and strongest stem. A suitable plant height ensures sufficient biomass for high yield, and higher stem stiffness, which was primarily attributed to thicker culm wall, greater density of the culm and leaf sheaths and higher cell wall component contents are the characteristics that should be taken into account to improving wheat lodging resistance.

Barley yellow dwarf virus em trigo no Brasil

The history of the barley yellow dwarf virus (BYDV) in Brazil began to be officially reported in 1968 when symptoms of yellowing in wheat were atributed to this ecological agent. The exact date of introductio of the virus in Brazil is unknown, but plants with symptoms similar to those caused by the virus and the aphid vectors had already been reported decades before the official diagnosis. After the identification of BYDV in Rio Grande do Sul, the virus was also found in other wheat regions in Santa Catarina, Paraná, São Paulo, Mato Grosso do Sul, Distrito Federal and Minas Gerais. This history will be explored from two points of view. First, considering the description of the variability of the viral population according to the detection and diagnosis methods and technologies available at each at me, and second, analyzing the impacts of changes in the Brazilian agricultural landscape and management practices on viral epidemiology

Impact of climate change on wheat yield and quality in the Yellow River Basin under RCP8.5 during 2020–2050

Studying the impact of future climate change on the yield and quality of wheat in the Yellow River Basin (YRB) is both essential for rationalizing the utilization of climate resources and ensuring national food security. In this study, we employed corrected refined meteorological grid data (30 km × 30 km) generated by the Climate–Weather Research and Forecasting model under RCP8.5, coupled with the DSSAT–CERES–Wheat model to predict the impact of climate change on wheat phenology, yield, and grain nitrogen content (GNC) in the YRB from 2020 to 2050. According to the type of wheat variety and planting management in the YRB, we designed five wheat ecological regions (I–V). The results show that from 2020 to 2050, the agro-meteorological resource, involving temperature, solar radiation, and precipitation, would have an overall increasing trend during the wheat growth seasons in the YRB. The growth period of wheat was generally shortened by approximately 8 d, including 6 d less from sowing to anthesis, and 2 d less from anthesis to maturity. In general, the predicted wheat yield showed a decreasing trend in the YRB, with an average reduction of 0.19% over the period from 2020 to 2050 compared with the baseline period from 1975 to 2005, and the spatial variation in wheat yield change was considerably large. In the future, the Qing‒Zang Spring Wheat region (V) in the western part of the YRB would be the only region with a yield increase of 35.4%, whereas the Northern Spring Wheat region (I) in the northern part of the YRB would be the region exhibiting the greatest decrease of 9.9%. Moreover, compared with the baseline, the GNC would increase by an average of 2.3% in the YRB, with a significant increase in the southern and central parts during 2020–2050. The GNC increase in the Huang‒Huai Winter Wheat region (III) was the highest with a 12.5% increment, but the Qing‒Zang Spring Wheat region (V) is the only region where GNC would decline, with an average decrease of 18.9%. This study implies that wheat yield and GNC have a negative correlation constraint. In general, winter wheat yield is less affected by future climate change, and the GNC of winter wheat would increase more than that of spring wheat in the YRB. Tapping the potential pathway for the balance of yield and GNC improvements under future climate change needs more exploration in the future. For instance, appropriate adjustment of the irrigation and fertilizer schedules and regimes could be considered and recommended to ensure the simultaneous improvement of wheat yield and quality in the YRB.

The Carotenoid Cleavage Dioxygenase Gene CCD7-B, at Large, Is Associated with Tillering in Common Wheat

Wheat, an important cereal crop, is responsible for the livelihoods of many people, and a component of national food security. Tillering, which determines plant architecture and spike number, is a critical agronomic trait of wheat. The carotenoid cleavage dioxygenase 7 (CCD7) has an important effect on the growth of tillers or lateral branches and lateral roots of plants. In order to study the relationship between CCD7 and tillering in wheat, CCD7-B was isolated from 10 Chinese wheat varieties with different tiller numbers. Subsequently, bioinformatics, allelic variation analysis, and field experiments were performed. Wheat CCD7-B belongs to the retinal pigment epithelial membrane receptor (RPE65) superfamily; it displays the greatest homology with monocot CCD7 proteins. Phylogenetic analysis of wheat CCD7-B proteins indicated division into dicotyledonous and monocotyledonous clades. Allelic variation analysis of CCD7-B via SrgAI enzyme digestion (a marker of cleaved amplified polymorphic sequences) suggested that 262 Chinese wheat micro-core collections and 121 Chinese wheat major cultivars from the Yellow and Huai River Valley winter wheat region can be divided into two groups: CCD7-B1 (C/T/T) and CCD7-B2 (G/C/A). CCD7-B1 showed better allelic variation than did CCD7-B2 for increasing the number of effective tillers of wheat varieties in China. This study provides reference data for the application of CCD7-B alleles to wheat breeding and supports further research regarding the mechanism of tillering in common wheat.

Climate change in the temperature and precipitation at two contrasting sites of the Argentinean wheat region

Global climate change is shifting temperature and precipitation regimes, which is modifying the environments that define wheat yield and quality. The current work characterises the changes that have occurred in the thermal and hydric environment in two contrasting sites of the wheat-growing region of Argentina, allowing comparison between sites for these changes and for how the changes are accelerating. Temperature and precipitation variables were analysed by regression and trend testing (Mann Kendall), and future projections were made based upon significant relationships. The two sites compared were in the zones around the cities of Azul in the Province of Buenos Aires and Marcos Juárez in the Province of Córdoba, located approximately 500 km apart. The climate data analysed covered the period 1931–2014 for Azul and 1952–2014 for Marcos Juárez. At both sites, temperatures increased significantly in mean and extreme values over these periods, where the rate of change accelerated during the first years of the twenty-first century. The changes observed were in general more pronounced in Marcos Juárez than in Azul. Furthermore, in Marcos Juárez, mean precipitation increased from September to December and there was a higher frequency of extremes of precipitation greater than 100 mm in September and October during the early twenty-first century. Evidence was found for temperature rise and the occurrence of extreme temperature and precipitation events occurring differently between sites, as well as for its acceleration rate in the early twenty-first century. The projected future changes made implied that wheat yield is expected to suffer losses over the coming century.