Huanghuaihai Region Research Articles

Design and Experiment of an Inter-Row Weeding Machine Applied in Soybean and Corn Strip Compound Planting (SCSCP)

To address the lack of specialized machinery for the mechanical weeding of SCSCP in the Huang Huai Hai region, this study designs a mechanized inter-row weeding machine for SCSCP. The machine features a reciprocating weeding shovel and an adaptive contouring mechanism for cultivation and soil loosening. This paper details the machine’s principles by analyzing the geometric relationship and mechanical model between the corresponding profiling quantities, which determine the relevant parameters for adaptive contouring to ensure stable operation on undulating ground. Furthermore, by optimizing the design of the weeding shovel’s reciprocating motion mechanism, combining EDEM simulation with the weeding shovel–soil interaction, it has been determined that, at various PTO shaft speeds, the optimal weeding efficacy is achieved with a blade-type weeding shovel structure when operating at a forward speed of 3.5 km/h. Field experiments were conducted with different PTO shaft speeds and weeding depths, using weeding and seedling injury rates as performance indicators. The results showed that, based on the optimal speed, the PTO shaft speed is 760 r/min, the operating depth is 3–5 cm, and the average row weeding rate is 90.4%. The average soybean and corn seedling injury rate is 3.4% and 4.2%, meeting the technical requirements for mechanical weeding.

Occurrence and distribution of phytic acid and its degradation products in soybeans in China: Analytical challenges

Phytic acid (IP6) and its degradation products lower myo-inositol phosphates exert different impacts on nutrient bioavailability and product quality characteristics. However, information regarding the occurrence of IP6 and its degradation products is scarce. In this work, simultaneous determination of IP6 and its degradation products in soybeans was developed, with emphasis on analysis by UPLC-MS/MS and a BEH Amide column both with hybrid surface technology. The retention and analyte/metal surface interactions issues were effectively addressed without ion-pairing reagents addition or derivatization. This method was applied to analyze soybeans from China. Total contents were 0.44–13.2 mg/g, and IP6 and its degradation product myo-inositol pentakisphosphate (IP5) were the predominant analytes, accounting for over 99%. Accession type significantly affected IP5 content, and landraces had significantly higher IP5 than cultivars. Geographically, the lowest IP6 was concentrated in the Huanghuaihai region. Significant correlations existed between IP6 and longitude, altitude, and annual cumulative sunshine hours. This study provides comprehensive insights into the IP6 and its degradation product profile in soybeans, which will benefit breeding soybeans based on specific requirements.

Amino acid substitutions in succinate dehydrogenase complex conferring resistance to the SDHI fungicide pydiflumetofen in Cochlibolus heterostrophus causing southern corn leaf blight1

Southern corn leaf blight (SCLB) caused by Cochlibolus heterostrophus, is a widespread foliar disease that has a substantial impact on maize yield in the Huanghuaihai region of China. Pydiflumetofen (Pyd), a new succinate dehydrogenase inhibitor (SDHI), has been found as a promising fungicide for the efficient control of SCLB, however, resistance of C. heterostrophus to Pyd has not been studied well. Here, five Pyd-resistant mutants were generated through fungicide adaptation. Sequence alignment analysis revealed that these mutants primarily mutated in ChSdhB and ChSdhD, with 3 genotypes: ChSdhBH277Y, ChSdhBI279T and ChSdhDH133Y, exhibiting two distinct categories of resistance: high resistance (HR) and moderate resistance (MR), which resistance factors (RF) is 214.22 and 44.33-53.67, respectively. These mutants were more pathogenic than the wild-type parental strains, but there was a significant reduction in mycelial growth rate and sporulation in the resistant mutants, indicating a significant fitness cost associated with resistance to Pyd. In addition, this study revealed a positive cross-resistance between Pyd and another SDHI fungicide cyclobutrifluram. However, no cross-resistance was found between Pyd and other classes of fungicide, including prochloraz, fludioxonil, iprodioneand pyraclostrobin. Homology modeling and molecular docking further confirmed that point mutation of ChSdhBH277Y, ChSdhBI279T, and ChSdhDH133Y could reduce binding affinity between Pyd and its target subunits from −74.07, −74.07, −152.52 kcal mol-1 to −3.90, −4.95, −9.93 kcal/mol, respectively. These findings not only provided valuable insights for managing SCLB caused by C. heterostrophus, but also enhanced our understanding of molecular mechanism underlying plant pathogen resistance to Pyd.

纵轴流玉米锥形脱粒装置优化设计与仿真分析

Aiming at the high crushing rate and impurity rate of corn kernel machine harvesting in the Huanghuaihai region, a longitudinal flow conical variable pitch threshing device is designed, which adopts the combined threshing element of "plate teeth + ribs" and the combined threshing concave plate of "leftward round tube type + vertical round tube type". The cob model was established, and the force analysis of the cob threshing process was carried out, and the type of threshing drum and the installation angle of the threshing concave plate round tube were determined as the main influencing factors, and the collision force on the corn cob was taken as the test index. Using EDEM discrete element simulation software, simulation tests were carried out on different types of threshing drums and threshing concave plates with different installation angles of round tubes with corn cobs, and the better threshing method was finally determined: a conical threshing drum at a drum speed of 450 r/min, and a combination of left-facing round-tube-type+vertical round-tube-type threshing concave plates with an installation angle of 10° (front-sparse and back-dense type) were used. Compared with the vertical circular tube type threshing concave plate, the corn cob contact force decreased from 313.5N to 247.3N, which was optimal for threshing in the range allowed by the corn kernel destructive force.

Investigation of Imidazolinone Herbicide Resistance Gene with KASP Markers for Japonica/Geng Rice Varieties in the Huanghuaihai Region of China.

Rice is a staple food for more than half of the global population due to its food security and sustainable development. Weeds compete with crops for sunlight and indispensable nutrients, affecting the yield and quality of crops. Breeding herbicide-tolerant rice varieties paired with herbicide application is expected to help with weed control. In this study, 194 Japonica/Geng rice varieties or lines collected from the Huanghuaihai region of China were screened by Kompetitive Allele-Specific PCR (KASP) markers based on four mutation sites within OsALS1 (LOC_Os02g30630), which is the target of imidazolinone (IMI) herbicides. Only the OsALS1627N haplotype was identified in 18 varieties, including the previously reported Jingeng818 (JG818), and its herbicide resistance was validated by treatment with three IMIs. To investigate the origin of the OsALS1627N haplotype in the identified varieties, six codominant PCR-based markers tightly linked with OsALS1 were developed. PCR analysis revealed that the other 17 IMI-tolerant varieties were derived from JG818. We randomly selected three IMI-tolerant varieties for comparative whole-genome resequencing with known receptor parent varieties. Sequence alignment revealed that more loci from JG818 have been introduced into IMI-tolerant varieties. However, all three IMI-tolerant varieties carried clustered third type single nucleotide polymorphism (SNP) sites from unknown parents, indicating that these varieties were not directly derived from JG818, whereas those from different intermediate improved lines were crossed with JG818. Overall, we found that only OsALS1627N from JG818 has been broadly introduced into the Huanghuaihai region of China. Additionally, the 17 identified IMI-tolerant varieties provide alternative opportunities for improving such varieties along with other good traits.

Refined Evaluation of Climate Suitability of Maize at Various Growth Stages in Major Maize-Producing Areas in the North of China

The Northeast region of China and Huang Huai Hai (3H) region are vital maize production bases in northern China that are crucial for national food security. The absence of phenological data hinders a detailed assessment of the alignment between maize development stages and climatic resources. This study combines the authors’ maize phenology data with climate suitability modeling to evaluate maize’s climate suitability at different developmental stages in both regions. This study shows that during the maize growth cycle, the average temperature, precipitation, sunshine, and comprehensive climate suitability were 0.77, 0.49, 0.87, and 0.65, respectively, in the Northeast. In contrast, the average temperature, precipitation, sunshine, and comprehensive climate suitability in the 3H region were 0.98, 0.53, 0.73, and 0.70, respectively. Precipitation is a major factor influencing maize growth, with temperature and sunshine impacting growth differently across regions. Temperature significantly affects maize in the Northeast, while sunshine plays a greater role in the 3H region. The Northeast is suitable for drought-resistant maize varieties, and implementing a late harvest policy in Liaoning could enhance maize yield. The 3H region generally has favorable climatic conditions. Apart from certain parts of Henan needing drought-resistant varieties, areas with ample growing seasons can adopt long-duration varieties to maximize thermal resource utilization. Our results have important implications for optimizing maize planting strategies and enhancing regional resilience, aiming to assess meteorological factors’ impact on maize growth in key production areas.

Design and test of tangential and longitudinal-axial threshing and separating unit for wheat

To achieve low loss and efficient wheat harvest in the Huanghuaihai region of China, this paper designed a tangential and longitudinal-axial threshing and separating unit (TLTSU). Key components such as the tangential threshing rotor (TTR), longitudinal-axial threshing rotor (LTR), and tangential concave were designed. Dynamic balance simulation of the threshing rotors was done to obtain the reaction forces at supporting ends of the threshing rotors and the amount of unbalance, and the amount of unbalance of the LTR was corrected to meet the standard requirement. Response surface optimization experiments of wheat threshing were conducted using throughput, TTR speed, and LTR speed as influencing factors and entrainment loss rate and impurity rate as test indicators. The regression models for the threshing device's entrainment loss rate and impurity rates were established. Through multi-objective parameter optimization analysis, the optimal threshing parameter combination for TLTSU was determined to be throughput of 8 kg s−1, TTR speed of 557 r·min−1, and LTR speed of 900 r·min−1. A validation experiment was conducted on this parameter combination, and the results showed that the entrainment loss rate was 0.27 % and the impurity rate was 28.23 %. The relative errors between the evaluation indicators and the predicted values of their regression models were 3.85 % and 1.4 %, respectively, which were less than 5 %, which proved the correctness of the regression model and provided a reference for the design of threshing and separating unit of wheat combine harvester.

Divergent selection of KNR6 maximizes grain production by balancing the flowering-time adaptation and ear size in maize.

Divergent selection of KNR6 maximizes grain production by balancing the flowering-time adaptation and ear size in maize.

Maize (Zea mays L.) responses to heat stress: Mechanisms that disrupt the development and hormone balance of tassels and pollen

AbstractGlobal climate changes have led to frequent and recurrent heat stress, which has seriously affected the world maize production. The experiment presented in this paper was carried out during the maize‐growing season in 2021 and 2022 at the Huang–Huai–Hai Region Maize Science and Technology Innovation Center (36°09′N, 117°09′E) in Tai'an, Shandong province, China. The test site is located in the semi‐humid warm temperate continental monsoon climate zone, soil is brown loam. We selected different heat‐sensitive maize varieties: heat‐tolerant variety Zhengdan 958 (ZD958) and heat‐sensitive variety Xianyu335 (XY335) to study the stress effects of high temperature on the development of tassel in the key stage of its differentiation (the 12‐leaf stage, V12). We found that exposure to heat stress during the V12 stage significantly reduced the tassel size and the anther dehiscence area, making it difficult to disperse pollen, thus effectively reducing pollen production. In addition, heat stress had significant negative effects on pollen development, resulting in deformed pollen and lower pollen viability and germination rate. Our results also showed that heat stress significantly increased the activities of key reactive oxygen species‐scavenging enzymes including superoxide dismutase, peroxidase and catalase, and that the malondialdehyde and H2O2 content in tassels exposed to heat stress were significantly higher than those control group, where it should be noted that for the XY335, these effects were more pronounced than for the ZD958. The endogenous hormone content of tassels exhibited a variety of responses. After heat stress, the zeatin and salicylic acid content in tassels of both maize varieties were significantly lower than those in the respective control groups, while the abscisic acid and gibberellin acid content were significantly higher. With respect to the jasmonic acid and 3‐indoleacetic acid content, the two maize varieties exhibited opposite responses: in tassels from ZD958 plants subjected to heat stress were higher than those in the respective control group, while in tassels from XY335 plants, they were lower. The observed changes in protective enzyme activities and endogenous hormone contents induced by heat stress significantly affected the development of maize tassels and significantly reduced the amount, activity and germination rate of pollen.

Genotype by Environment Interaction Analysis for Grain Yield and Yield Components of Summer Maize Hybrids across the Huanghuaihai Region in China

Increasing the maize production capacity to ensure food security is still the primary goal of global maize planting. The purpose of this study was to evaluate genotypes with high yield and stability in summer maize hybrids grown in the Huanghuaihai region of China using additive main effects and multiplicative interaction (AMMI) analysis and best linear unbiased prediction (BLUP) technique. A total of 18 summer maize hybrids with one check hybrid were used for this study using a randomized complete block design (RCBD) with three replicates at 74 locations during two consecutive years (2018–2019). A three-way analysis of variance (ANOVA) and an AMMI analysis showed that genotype (G), environment (E), year (Y) and their interactions were highly significant (p < 0.001) except G × E × Y for all evaluated traits viz., grain yield (GY), ear length (EL), hundred seed weight (HSW) and E × Y for hundred seed weight. The first seven interaction principal components (IPCs) were highly significant and explained 81.74% of the genotype by environment interaction (GEI). By comparing different models, the best linear unbiased prediction (BLUP) was considered the best model for data analysis in this study. The combination of AMMI model and BLUP technology to use the WAASB (weighted average of absolute scores from the singular value decomposition of the matrix of BLUP for GEI effects generated by linear mixed model) index was considered promising for similar research in the future. Genotypes H321 and Y23 had high yield and good stability, and could be used as new potential genetic resources for improving and stabilizing grain yield in maize breeding practices in the Huanghuaihai region of China. Genotypes H9, H168, Q218, Y303 and L5 had narrow adaptability and only apply to specific areas. The check genotype Z958 had good adaptability in most environments due to its good stability, but it also needs the potential to increase grain yield. Significant positive correlations were also found between the tested agronomic traits.

Optimizing planting density and nitrogen application to enhance profit and nitrogen use of summer maize in Huanghuaihai region of China

Low planting density and irrational nitrogen (N) fertilization are two common practices in conventional cropping of smallholder maize production in Huanghuaihai region of China. A 2-year field experiment was carried out to study the effects of N application and planting density on maize phenology, dry matter accumulation, profit, yield, N uptake and efficiency indices. The experiments included three N application levels (120 kg ha−1, N1; 180 kg ha−1, N2; 240 kg ha−1, N3) and three planting densities (60,000 plants ha−1, D1; 75,000 plants ha−1, D2; 90,000 plants ha−1, D3). Increasing N input and planting density delayed the physiological maturity and enhanced dry matter accumulation. Comparing with the traditional N3 level, grain yield and profit were kept stable at N2 level and decreased at N1 level, partial factor productivity of applied N (PFPN) and nitrogen efficiency ratio (NER) were increased with the decreasing of N level. Comparing with the traditional D1 density, grain yield, profit and PFPN were increased at D2 density and then kept stable at D3 density, NER was kept stable at D2 density and then decreased at D3 density. Based on the predicted maximum profit, the optimal combinations of N application and planting density were 199 kg ha−1 and 81,081 plants ha−1 in 2017, and 205 kg ha−1 and 84,782 plants ha−1 in 2018. The two optimal combinations had an increase of 17.6% for grain yield, 39.8% for PEPN, 3.6% for NRE than the traditional N3D1 treatment. Therefore, an appropriate combination of increased planting density with reduced N application could enhance profit and nitrogen use of summer maize in Huanghuaihai region of China.

Putative variants, genetic diversity and population structure among Soybean cultivars bred at different ages in Huang-Huai-Hai region

Soybean cultivars bred in the Huang-Huai-Hai region (HR) are rich in pedigree information. To date, few reports have exposed the genetic variants, population structure and genetic diversity of cultivars in this region by making use of genome-wide resequencing data. To depict genetic variation, population structure and composition characteristics of genetic diversity, a sample of soybean population composed all by cultivars was constructed. We re-sequenced 181 soybean cultivar genomes with an average depth of 10.38×. In total, 11,185,589 single nucleotide polymorphisms (SNPs) and 2,520,208 insertion-deletions (InDels) were identified on all 20 chromosomes. A considerable number of putative variants existed in important genome regions that may have an incalculable influence on genes, which participated in momentous biological processes. All 181 varieties were divided into five subpopulations according to their breeding years, SA (1963–1980), SB (1983–1988), SC (1991–2000), SD (2001–2011), SE (2012–2017). PCA and population structure figured out that there was no obvious grouping trend. The LD semi-decay distances of sub-population D and E were 182 kb, and 227 kb, respectively. Sub-population A (SA) had the highest value of nucleotide polymorphism (π). With the passage of time, the nucleotide polymorphism of SB and SC decreased gradually, however that of SD and SE, opposite to SB and SC, gave a rapid up-climbing trend, which meant a sharp increase in genetic diversity during the latest 20 years, hinting that breeders may have different breeding goals in different breeding periods in HR. Analysis of the PIC statistics exhibited very similar results with π. The current study is to analyze the genetic variants and characterize the structure and genetic diversity of soybean cultivars bred in different decades in HR, and to provide a theoretical reference for other identical studies.

Input Structure Effect of Total Factor Productivity Growth of Animal Husbandry

This paper uses the input-output panel data of China's animal husbandry industry from 1997 to 2017, based on the total factor decomposition framework of total factor productivity (TFP), and uses the Hicks-Moorsteen index completely decompose the growth of animal husbandry TFP. By measuring the effect of mixed efficiency on the development of TFP in animal husbandry and then evaluating the input structure effect of TFP growth in animal husbandry. The results show that the impact of input structure on the TFP growth of animal husbandry has also changed from negative to positive. From 1997 to 2007, the input structure of the Huanghuaihai region alone contributed to the growth of TFP in animal husbandry, and the rest of the region was the opposite. From 2008 to 2017, the input structure of the Mengxin Plateau region hindered the growth of TFP in animal husbandry, while the rest of the region was the opposite.

Effects of phytase Q9 on the yield and senescence characteristics of summer maize shaded in the field

Light shortage in the canopy of summer maize resulted from the decrease of solar radiation and the increase of planting density in Huanghuaihai region could reduce maize yield. In order to explore the effects of phytase Q9 on leaf senescence characteristics of summer maize, three sha-ding treatments with summer maize hybrid 'Denghai 605' (DH605) were conducted, including shading at flowering to maturity stage (S1), shading at ear stage (S2), and shading at whole growth stage (S3) with natural lighting in the field as control (CK). Chemical control reagent phytase Q9 was used to regulate the shading treatments (the original solution was diluted by 100 times) and the CK exogenously, namely shading at flowering to maturity stage-phytase Q9 (S1Q), shading at ear stage-phytase Q9 (S2Q), and shading at whole growth stage-phytase Q9 (S3Q), and natural lighting-phytase Q9 (CKQ), with spraying water at the same stage as the control. The results showed that leaf area index (LAI), soil-plant analysis development (SPAD) value and net photosynthetic rate of summer maize was significantly reduced by shading, which led to decreases of yield. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in ear-leaf decreased. The content of malondialdehyde (MDA) and free proline increased, and that of soluble protein decreased. The spraying phytase Q9 significantly increased LAI, SPAD and net photosynthetic rate in S3Q and S2Q. MDA and free proline content in S3Q, S2Q, and S1Q were significantly decreased, and soluble protein content and POD activity was significantly increased. SOD and CAT activities in S2Q and S3Q were significantly increased. The yield of S3Q, S2Q and S1Q were 19%, 8% and 7% higher than that of S3, S2 and S1 respectively. There was no significant difference between CKQ and CK. In conclusion, phytase Q9 could effectively alleviate the negative impact of low light on yield formation of summer maize, and increase grain yield by improving photosynthetic capacity of leaves and delaying leaf senescence.

Spatio-temporal characteristics of agro-climatic indices and extreme weather events during the growing season for summer maize (Zea mays L.) in Huanghuaihai region, China.

The stability of maize production is essential to global food security. Climate factors, such as temperature, precipitation, and solar radiation, directly affect the development of maize plants and hence the final grain yield. In this study, we investigated the spatial distributions and temporal trends of agro-climatic indices and severe weather indicators during the actual growing season for summer maize in Huanghuaihai region of China. The results showed that during the growing season, accumulated effective thermal time had significantly increased. From R3 to R6, accumulated effective thermal time, effective precipitation, and photosynthesis active radiation all showed an increasing trend, with the rate of 20.3°Cday, 1.1mm, and 7.3MJm-2 per decade, respectively. From VE to R3, most of the study years showed a > 50% ratio of high-temperature days to subtotal days and > 7 consecutive days without available precipitation. During most of the study years, there were at least 0.5 thunderstorm events from V6 to VT stage in the locations of study; days with strong winds accounted for more than half the subtotal days during the V6-VT stage. And potential risk of lodging may be reduced by the decrease in days with strong wind. The results of this study could be used in optimizing agricultural management in summer maize production in order to take advantage of beneficial climatic elements while combating adverse climatic elements.

A new Curvularia lunata variety discovered in Huanghuaihai Region in China

The purpose of this study was to identify the dominant pathogens of Curvularia leaf spot and their pathogenicity variation in Huanghuaihai Region of China in recent years. In 2013 and 2016–2017, the occurrences of Curvularia leaf spots on maize were investigated in fields located in Henan, Hebei, Shandong, and Anhui provinces, and 292 fungi were isolated from diseased leaves. These fungal isolates were subjected to morphological identification, and 232 isolates were found to have about 70% uncurved conidia and were identified as Curvularia lunata var. Most of the conidia of 2 representative isolates, namely, HNWB-131 and HNWB-185, were oblong with parallel septations and were distinctly different from a reference isolate CX-3. For further determination, the internal transcribed spacer (ITS), glyceraldehyde 3-phosphate dehydrogenase (GPDH), the large subunit (LSU), and translation elongation factor 1-alpha (EF1-α) sequences of HNWB-131, HNWB-185, and CX-3 were amplified and sequenced. The results of sequence analysis showed that the 4 gene sequences from the 3 isolates had a similarity of more than 99% to C. lunata. Based on the sequences of ITS and the combined data of the 4 genes, neighbor-joining trees were constructed for phylogenetic analysis. The results indicated that these 3 isolates were clustered together with C. lunata. The expression of Clg2p and ClUrase genes in mycelia and conidia was significantly (P<0.05) higher in CX-3 than in HNWB-131 and HNWB-185. This study found that the dominant pathogen of Curvularia leaf spot was a new variety of C. lunata with morphological variations in Huanghuaihai Region from 2013 to 2017. The pathogenicity of the C. lunata var. was not significantly enhanced, and the expression of Clg2p and ClUrase genes of C. lunata var. was decreased.

Evaluation and Comparison of Random Forest and A-LSTM Networks for Large-scale Winter Wheat Identification

Machine learning comprises a group of powerful state-of-the-art techniques for land cover classification and cropland identification. In this paper, we proposed and evaluated two models based on random forest (RF) and attention-based long short-term memory (A-LSTM) networks that can learn directly from the raw surface reflectance of remote sensing (RS) images for large-scale winter wheat identification in Huanghuaihai Region (North-Central China). We used a time series of Moderate Resolution Imaging Spectroradiometer (MODIS) images over one growing season and the corresponding winter wheat distribution map for the experiments. Each training sample was derived from the raw surface reflectance of MODIS time-series images. Both models achieved state-of-the-art performance in identifying winter wheat, and the F1 scores of RF and A-LSTM were 0.72 and 0.71, respectively. We also analyzed the impact of the pixel-mixing effect. Training with pure-mixed-pixel samples (the training set consists of pure and mixed cells and thus retains the original distribution of data) was more precise than training with only pure-pixel samples (the entire pixel area belongs to one class). We also analyzed the variable importance along the temporal series, and the data acquired in March or April contributed more than the data acquired at other times. Both models could predict winter wheat coverage in past years or in other regions with similar winter wheat growing seasons. The experiments in this paper showed the effectiveness and significance of our methods.

Compositional differences between conventional Chinese and genetically modified Roundup Ready soybeans

Glyphosate-tolerant genetically modified (GM) soybeans (Glycine max (L.) Merr.), known commercially as Roundup Ready soybeans, dominate oil consumption and are partly used for protein intake in China. Chemical composition of soybean seed determines its nutritional value, its processing suitability for various protein products, and market decisions. We conducted a compositional comparison of eight GM and 16 conventional Chinese representative soybean varieties. Crude protein, crude fat, moisture, ash, carbohydrate, crude fibre, amino acid and fatty acid contents of the different soybean genotypes were compared and analysed. The GM soybeans had the highest oil concentration but poorer quality, whereas conventional soybeans from the Huanghuaihai region of China showed significantly higher protein, total amino acid, essential amino acid and oleic acid contents, and lower n-6:n-3 ratio and carbohydrate content, which suggested superior nutritional value. Principal component analysis indicated that protein, carbohydrates and amino acids (except tryptophan, methionine, tyrosine, histidine and proline) contributed most to distinguishing GM soybeans from conventional Chinese soybeans. Differences among the GM and conventional soybeans collected from two major producing regions in China can help to guide manufacturing processes and market decisions with respect to soybeans. High protein and amino acid content in conventional Chinese soybeans mean the potential to expand and improve the International Life Sciences Institute Crop Composition Database used for safety assessment of GM soybean.

Response of net primary production to land use and land cover change in mainland China since the late 1980s

Land use and land cover patterns in mainland China have substantially changed in the recent decades under the economic reform policies of the government. The terrestrial carbon cycle, particularly the net primary productivity (NPP), has been substantially changed on both local and national scales. With the growing concern over the effects of the terrestrial carbon cycle on global climate changes, the impacts of land use and cover change (LUCC) on NPP need to be understood. In this study, variations in NPP caused by LUCC (e.g., urbanization and conversion of other land use to forest and grassland) in mainland China from the late 1980s to 2015 were evaluated based on land cover datasets and NPPs simulated from the Carnegie–Ames–Stanford Approach model. The results indicate that the national total losses in NPP attributed to urbanization reached 1.695 TgC between the late 1980s and 2015. A large proportion (63.02%) of the total losses was due to the transformation from cropland to urban land. Urban expansion decreased the monthly and total NPPs over southern China, which includes the South China Region, Southwest China Region, and the middle and lower regions of the Yangtze River. However, the total NPP increased in the majority of urbanized areas in Northern China, including the Huang–Huai–Hai Region, Inner Mongolia Region (MGR), Gan-Xin Region (GXR), and Northeast China Region; monthly NPP in GXR and MGR increased throughout the year. By contrast, the conversion to grassland or forestland increased the monthly and total NPPs of Northern China, suggesting that returning to forestland and grassland could increase the carbon sequestration capacity of terrestrial ecosystems in mainland China. Among the sub-regions, the Loess Plateau Region contributed the largest increase in NPP, which was prompted by the conversion to grassland and forestland.

Occurrence of Puccinia polysora Causing Southern Corn Rust in the Northeast Huanghuaihai Region of China

Occurrence of <i>Puccinia polysora</i> Causing Southern Corn Rust in the Northeast Huanghuaihai Region of China