The practice of intercropping leguminous and gramineous crops is used for promoting sustainable agriculture, optimizing resource utilization, enhancing biodiversity, and reducing reliance on petroleum products.  However, promoting conventional intercropping strategies in modern agriculture can prove challenging.  The innovative technology of soybean maize strip intercropping (SMSI) has been proposed as a solution.  This system has produced remarkable results in improving domestic soybean and maize production for both food security and sustainable agriculture.  In this article, we provide an overview of SMSI and explain how it differs from traditional intercropping.  We also discuss the core principles that foster higher yields and the prospects for its future development.

Monoclonal antibodies (mAbs) are widely used in virus research and disease diagnosis.  The nucleoprotein (NP) of influenza A virus (IAV) plays important roles in multiple stages of the virus life cycle.  Therefore, generating conserved mAbs against NP and characterizing their properties will provide useful tools for IAV research.  In this study, two mAbs against the NP protein, 10E9 and 3F3, were generated with recombinant truncated NP proteins (NP-1 and NP-2) as immunogens.  The heavy-chain subclass of both 10E9 and 3F3 was determined to be IgG2α, and the light-chain type was κ.  Truncation and site-specific mutation analyses showed that the epitopes of mAbs 10E9 and 3F3 were located in the N terminal 84–89 amino acids and the C terminal 320–324 amino acids of the NP protein, respectively.  We found that mAbs 10E9 and 3F3 reacted well with the NP protein of H1–H15 subtypes of IAV.  Both 10E9 and 3F3 can be used in immunoprecipitation assay, and 10E9 was also successfully applied in confocal microscopy.  Furthermore, we found that the 10E9-recognized ₈₄SAGKDP₈₉ epitope and 3F3-recognized ₃₂₀ENPAH₃₂₄ epitope were highly conserved in NP among all avian and human IAVs.  Thus, the two mAbs we developed could be used as powerful tools in the development of diagnostic methods of IAV, and also surely promote the basic research in understanding the replication mechanisms of IAV.

The cereal cyst nematode, Heterodera avenae, is one of the most economically important pathogens impacting the worldwide production of cereals and is widely distributed in more than 16 regions in China.  The present study used the numbers of nematodes inside the plant roots to evaluate the resistance/susceptibility of different subpopulations of barley Hordeum vulgare (QH2R, QH6R and TB2R) to H. avenae under field and pot conditions.  Nematode development in two highly resistant varieties was also evaluated by in vivo experiment and microscopic observation.  Analyses of 186 selected varieties showed the numbers of susceptible varieties identified with the number of females/cysts per plant (NFP) method were significantly higher than those identified with the Pf/Pi ratio (PPR) method, which indicated that the NFP method rather than the PPR method is more reliable to evaluate the resistance of barley.  The field and pot experiment results indicated that the QH2R subpopulation had lower females/cysts numbers than QH6R and TB2R subpopulations, and eight HR varieties (Sunong 7617, Sunong 7635, Dongyuan 87-14, Rudong 14-46, Rudong 87-57, Rudong 87-8-45, Rudong 88-14-2, and Rudong 88-67-1) were identified in QH2R, with the NFP numbers below 4.2.  Further microscopic observation of nematode development suggested that H. avenae often penetrated less into highly resistant varieties (Sunong 7635 and Dongyuan 87-14) and more frequently failed to develop into females than the susceptible barleys.  The promising resistant varieties identified in the present research might be helpful for breeders to develop CCN-resistant cultivars and control H. avenae populations effectively at low costs.

Grain zinc (Zn) and iron (Fe) concentrations and their responses to foliar application of micronutrients in 28 Chinese wheat landraces and 63 cultivars were investigated in a two-year field experiment.  The average grain Zn and Fe concentrations were 41.8 mg kg^–1 (29.0−63.3 mg kg^–1) and 39.7 mg kg^–1 (27.9−67.0 mg kg^–1), respectively.  Compared with cultivars, landraces had greater grain Zn (11.0%) and Fe (4.8%) concentrations but lower harvest index (HI), grain weight per spike (GWS), grain number per spike (GNS) and thousand grain weight (TGW).  Both Zn and Fe concentrations were negatively and significantly correlated with HI, GWS, and GNS, while showed a poor association with TGW, suggesting that lower HI, GWS, and GNS, but not TGW, accounted for higher Zn and Fe concentrations for landraces than for cultivars.  Grain Zn concentrations of both cultivars and landraces significantly increased after foliar Zn spray and the increase was two-fold greater for landraces (12.6 mg kg^–1) than for cultivars (6.4 mg kg^–1).  Foliar Fe spray increased grain Fe concentrations of landraces (3.4 mg kg^–1) and cultivars (1.2 mg kg^–1), but these increases were not statistically significant.  This study showed that Chinese wheat landraces had higher grain Zn and Fe concentrations than cultivars, and greater increases occurred in grain Zn concentration than in grain Fe concentration in response to fertilization, suggesting that Chinese wheat landraces could serve as a potential genetic source for enhancing grain mineral levels in modern wheat cultivars.

Dry matter intake (DMI) prediction models of NRC (2001), Fox et al. (2004) and Fuentes-Pila et al. (2003) were targeted in the present study, and the objective was to evaluate their prediction accuracy with feeding trial data of 32 lactating Holstein cows fed two total mixed rations with different forage source.  Thirty-two cows were randomly assigned to one of two total mixed ration groups: a ration containing a mixed forage (MF) of 3.7% Chinese wildrye, 28.4% alfalfa hay and 26.5% corn silage diet and another ration containing 33.8% corn stover (CS) as unique forage source.  The actual DMI was greater in MF group than in CS group (P=0.064).  The NRC model to predict DMI resulted in the lowest root mean square prediction error for both MF and CS groups (1.09 kg d^–1 vs. 1.28 kg d^–1) and the highest accuracy and precision based on concordance correlation coefficient for both MF and CS diet (0.89 vs. 0.87).  Except the NRC model, the other two models presented mean and linear biases in both MF and CS diets when prediction residuals were plotted against predicted DMI values (P<0.001).  The DMI variation in MF was caused by week of lactation (55.6%), milk yield (13.9%), milk fat percentage (7.1%) and dietary neutral detergent fiber (13.3%), while the variation in CS was caused by week of lactation (50.9%), live body weight (28.2%), milk yield (8.4%), milk fat percentage (5.2%) and dietary neutral detergent fibre (3.8%).  In a brief, the NRC model to predict DMI is comparatively acceptable for lactating dairy cows fed two total mixed rations with different forage source.

Biochar has been shown to influence soil microbial communities in terms of their abundance and diversity.  However, the relationship among microbial abundance, structure and C metabolic traits is not well studied under biochar application.  Here it was hypothesized that the addition of biochar with intrinsic properties (i.e., porous structure) could affect the proliferation of culturable microbes and the genetic structure of soil bacterial communities.  In the meantime, the presence of available organic carbon in biochar may influence the C utilization capacities of microbial community in Biolog Eco-plates.  A pot experiment was conducted with differenct biochar application (BC) rates: control (0 t ha^–1), BC1 (20 t ha^–1) and BC2 (40 t ha^–1).  Culturable microorganisms were enumerated via the plate counting method.  Bacterial diversity was examined using denaturing gradient gel electrophoresis (DGGE).  Microbial capacity in using C sources was assessed using Biolog Eco-plates.  The addition of biochar stimulated the growth of actinomyces and bacteria, especially the ammonifying bacteria and azotobacteria, but had no significant effect on fungi proliferation.  The phylogenetic distribution of the operational taxonomic units could be divided into the following groups with the biochar addition: Firmicutes, Acidobacteria, Gemmatimonadetes, Actinobacteria, Cyanobacteria and α-, β-, γ- and δ-Proteobacteria (average similarity >95%).  Biochar application had a higher capacity utilization for L-asparagine, Tween 80, D-mannitol, L-serine, γ-hydroxybutyric acid, N-acetyl-D-glucosamine, glycogen, itaconic acid, glycyl-L-glutamic acid, α-ketobutyricacid and putrescine, whereas it had received decreased capacities in using the other 20 carbon sources in Biolog Eco-plates.  Redundancy analysis (RDA) revealed that the physico-chemical properties, indices of bacterial diversity, and C metabolic traits were positively correlated with the appearance of novel sequences under BC2 treatment.  Our study indicates that the addition of biochar can increase culturable microbial abundance and shift bacterial genetic structure without enhancing their capacities in utilizing C sources in Biolog Eco-plates, which could be associated with the porous structure and nutrients from biochar.

The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate (MeJA) and gibberellins (GA₃) to oilseed plants (Brassica napus L.) interrupts the delicate endogenous balance and results in various floral organ abnormalities. Exogenous MeJA or GA₃ influences the transcriptome at the initial flowering stage in Arabidopsis, but the corresponding changes of transcriptome in floral tissues of oilseed rape remain unknown. In this study, cDNA-amplified fragment length polymorphism (cDNA-AFLP) was analyzed to identify genes whose expression was modulated by application of MeJA and GA₃ to flower buds. A total of 2 787 cDNA fragments were counted using 64 primer pair combinations, and bands larger than 50 bp were compared among four treatments, namely, water control, MeJA (50 µmol L^-1), MeJA (100 µmol L^-1), and GA₃ (50 µmol L^-1). Overall, 168 transcript-derived fragments (TDFs) were differentially expressed among the treatments. The expression pattern of some TDFs was confirmed by semi-quantitative RT-PCR analysis, and a group of 106 differentially displayed TDFs was cloned and sequenced. Homologs of Arabidopsis genes were identified and classified into 12 functional categories. A total of 34, 39, and 24 TDFs were responsive to GA_3, MeJA, and both GA₃ and MeJA, respectively. This finding indicated that cross-talk between these two hormones may be involved in regulating flower development. This study provides potential target genes for manipulation in terms of flowering time and floral organ initiation, important agronomic traits of oilseed rape.

  Rapeseed (Brassica napus), is an important source of edible oil, animal fodder, vegetables, condiments and biodiesel, and plays a significant role in securing edible oil production worldwide. However, in countries with comparatively low levels of agricultural mechanization, such as China, increasing costs of labor and agricultural inputs are decreasing rapeseed profitability, and hence the area of rapeseed under cultivation. If the value of rapeseed crops is not further increased, the rapeseed growing area will continue to decrease, potentially jeopardizing oil production. Therefore, full exploitation of the existing and potential value of rapeseed is desirable. Different rapeseed products are already utilized in different ways, with more applications currently underutilized. As well as oil extraction from the seeds, the shoot and leaves can be used as vegetables, the roots to absorb soil cadmium for pollution remediation, the flowers for sightseeing and as a source of nectar, the pollen for extracting flavonoids and useful amino acids, the seeds/seed meal for extracting isthiocyanates and other important sulforaphane compounds, the straw and seed meal for fodder, and immature whole plants for green manure. This review summarizes recent research on ways to explore the potential holistic value of rapeseed, by taking the example of multifunctionality of rapeseed in China.

In legume plants, uricase gene (Nodulin-35) plays a positive role in metabolism of ureide and amide compounds in symbiotic nitrogen-fixing in the nodules. In this study, a pot experiment was performed to examine the effects of ammonium application on the transcription of MsU2 gene and distribution of major nitrogen compounds in alfalfa Medicago sativa. Data showed that alfalfa plant has a significant difference in contents of nitrogen compounds in xylem saps compared with soybean plant, and belongs to typical amide type legume plants with little ureide accumulation, and the accumulation of asparagines and ureide in the tissues of alfalfa is mainly gathered in the nodules. Northern blotting showed that excessive ammonium significantly inhibited the transcription of MsU2 gene in the nodules and roots, and mRNA accumulation of MsU2 gene in the plants exposed to excessive ammonium decreased gradually with culture time extension, indicating that application of ammonium significantly inhibited the transcription of MsU2 gene in the alfalfa plants. Although the application of excessive ammonium increased the contents of amino acids in various tissues of alfalfa, the accumulation of allantoin reflecting the strength of uricase activity is remarkably reduced in the xylem saps, stems and nodules when alfalfa plants exposed to excessive ammonium, suggesting that application of excessive ammonium generated a negative effect on symbiosis fixing-nitrogen system due to inhibition of ammonium ion on uricase activity in the nodules of alfalfa. This result seems to imply that application of excessive ammonium in legume plants should not be proposed to avoid affecting the ability of fixing nitrogen in the nodules of legume plants, and reasonable dose of ammonium should be recommended to effectively utilize the fixed N from atmosphere in legume plant production.

Aquaporin proteins were demonstrated to play an important regulatory role in transporting water and other small molecules. To better understand physiological functions of aquaporins in extremophile plants, a novel ThPIP1 gene from the Thellungiella halophila was isolated and functionally characterized in the transgenic rice. Data showed that the ThPIP1 protein encoded 284 amino acids, and was identified to be located on the plasma membrane. The expression of ThPIP1 gene in the shoots and roots of T. halophila seedlings were induced by high salinity. The transgenic rice overexpressing ThPIP1 gene significantly increased plants tolerance to salt stress through the pathway regulating the osmotic potentials, accumulation of organic small molecules substances and the ratio of K+/Na+ in the plant cells. Moreover, split-ubiquitin yeast two-hybrid assay showed that ThPIP1 protein specifically interacted with ThPIP2 and a non-specific lipid-transfer protein 2, suggesting that ThPIP1 probably play a key role in responding to the reactions of multiple external stimulus and in participating in different physiological processes of plants exposed to salt stress.

The rice leaffolder (RLF), Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae), and the white-backed rice planthopper (WBPH), Sogatella furcifera Horváth (Hemiptera: Delphacidae), are major insect pests in China and several other Asian countries. These two pests commonly occur simultaneously or in a temporal sequence. Thus, the investigation of the effect of complex infestations or temporal sequence infestations by these pests on rice yield has a practical significance for the control of these pests. The present study comprised experiments with the following four different variables in potted rice at the tillering stage: single pest species infestation, complex infestation, complete combination infestation and temporal sequence infestation (C. medinalis infestation prior to S. furcifera and S. furcifera infestation prior to C. medinalis). The results showed that the four infestations resulted in a significant decrease in 1 000-grain weight (1 000GW) and rate of yield loss (RYL) but an increase in blighted grain rate (BGR), with a significant positive correlation with the infestation density. However, the influences of the complex infestation, complete combination infestation or sequence infestation on the 1 000GW, BGR and RYL were greater than those of the single pest species infestations but did not have addition effects, i.e., the effects of the complex infestation and combination infestation or sequence infestation on the 1 000GW, BGR and RYL were less than the additive effects of the two single pest species infestations at the same densities. In the condition of the same total infestation pressure, no significant differences in the 1 000GW, BGR and RYL were found between C. medinalis infestation prior to S. furcifera and S. furcifera infestation prior to C. medinalis as well as between the sequence infestation and the complex infestation.

The variation among Chinese genotypes of Brassica napus L. for seed tocopherols content and their analysis using gas chromatography has not been comprehensively reported till to date. In the present study, the tocopherol contents of four Chinese genotypes of Brassica napus L., namely, Gaoyou 605, Zhejiang 619, Zheshuang 758, and Zheshuang 72, were evaluated using three modified sample preparation protocols (P1, P2, and P3) for tocopherol extraction. These methods were distinguished as follows. Protocol one (P1) included the evaporation of solvent after extraction without silylation. Protocol two (P2) followed the direct supernatant collection after overnight extraction without drying and silylation. Protocol three (P3) included trimethylsilylation with N,O-bis(trimethylsilyl) trifluoroacetamide. Genotypic comparison of tocopherol and its isoforms revealed that Gaoyou 605 was dominant over the other genotypes with (140.5±10.5), (316.2± 9.2), and (559.1± 24.3) μg g-1 of seed meal α-, γ-, and total (T-) tocopherol, respectively, and a 0.44±0.04 α- to γ-tocopherol ratio. The comparison of the sample preparation protocols, on the other hand, suggests that P3 is the most suitable method for the tocopherol extraction from Brassica oilseeds and for the analysis of tocopherols using gas chromatography flame ionization detector (GC-FID). Trimethylsilylation is the key step differentiating P3 from P1 and P2. Variations detected in tocopherol contents among the Chinese rapeseed (B. napus) genotypes signify the need to quantify a wide range of rapeseed germplasm for seed tocopherol dynamics in short and crop improvement in long.

To elucidate the differential gene expression patterns in soybeans during infection by Phytophthora sojae, a cDNA libraryfor suppression subtractive hybridization (SSH) was constructed with cDNAs from soybean cultivar Suinong 10 treatedwith sterile distilled water as the driver and cDNAs from Suinong 10 inoculated with P. sojae as the tester. A total of 2 067recombinant colonies from the SSH library were randomly picked, amplified, and sequenced. After discarding 312 poorquality expressed sequence tags (EST), 1 755 high quality ESTs were assembled and edited to 1 384 tentatively uniquegenes (TUG), in which, 586 showed significant homology to known sequences, and 798 had low homology or no matchwith the known sequences. A cDNA microarray containing 307 singletons from the 586 TUGs and 222 singletons from the798 TUGs was developed to characterize differentially expressed cDNAs in the SSH library, and eight cDNAs wereidentified to be up-regulated after microarray analysis and then confirmed by real-time PCR. They were homologous to theprotein 10, and were also related to some proteins in disease resistance response, such as pathogen-related protein,phenylalanine ammonia-lyase, isoflavone reductase, WRKY transcription factor 31, major allergen Pru ar 1, and pleiotropicdrug resistance protein 12. Most of the up-regulated cDNAs encode enzymes of phytoalexin biosynthesis andpathogenesis-related proteins involved in plant disease resistance. Here, we fist reported the Pru ar 1 in soybeans. Thefindings of this research have contributed to better understanding of soybean resistance to P. sojae at the molecular level.

Rapeseed (Brassica napus L.) is one of the most important oilseed crops worldwide.  Development of rapeseed varieties with high-quality oil is a long-term breeding goal.  Reducing the contents of palmitic acid, the main saturated fatty acid in rapeseed oil, could greatly improve oil quality.  Here, we performed genome-wide association study (GWAS) and transcriptome-wide association study (TWAS) of seed palmitic acid content (SPAC) using 393 diverse B. napus accessions.  Four genes (BnaA08.DAP, BnaA08.PAA1, BnaA08. DUF106, and BnaC03.DAP) were identified by both GWAS and TWAS.  The transcripts per million (TPM) values of these candidate genes at 20 and 40 days after flowering (DAF) were significantly correlated with SPAC in this association panel.  Based on genetic variation in the candidate genes, we identified four low-SPAC haplotypes by combining candidate gene association analysis and haplotype analysis.  Brassica napus accessions carrying low-SPAC haplotypes had lower SPAC than those carrying high-SPAC haplotypes without affecting seed oil content, seed protein content, or seed yield.  Based on the functional single-nucleotide polymorphism (SNP) chrA08_9529850 (C/A) in the promoter of BnaA08.DUF106, we developed a molecular marker (Bn_A8_SPAC_Marker) that could be used to facilitate breeding for low SPAC in B. napus.  Our findings provide valuable information for studying the genetic control of SPAC in B. napus.  Moreover, the candidate genes, favorable haplotypes, and molecular marker identified in this study will be useful for breeding low-SPAC B. napus varieties.