Virus-induced gene silencing (VIGS) and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas) systems are effective technologies for rapid and accurate gene function verification in modern plant biotechnology.  However, the investigation of gene silencing and editing in radish remains limited.  In this study, a bleaching phenotype was generated through the knockdown of RsPDS using tobacco rattle virus (TRV)- and turnip yellow mosaic virus (TYMV)-mediated gene silencing vectors.  The TYMV-mediated gene silencing efficiency was higher than the TRV-based VIGS system in radish.  The expression level of RsPDS was significantly inhibited using VIGS in ‘NAU-067’ radish leaves.  The rootless seedlings of ‘NAU-067’ were infected with Agrobacterium rhizogenes using the 2300GN-Ubi-RsPDS-Cas9 vector with two target sequences.  Nine adventitious roots were blue with GUS staining, and four of these adventitious roots were edited at target sequence 1 of the RsPDS gene as indicated by Sanger sequencing.  Furthermore, albino lines were generated with A. tumefaciens-mediated transformation of radish cotyledons.  Five base substitutions and three base deletions occurred at target sequence 2 in Line 1, and three base insertions and three base substitutions occurred at target sequence 1 in Line 2.  This study shows that VIGS and CRISPR/Cas9 techniques can be employed to precisely verify the biological functions of genes in radish, which will facilitate the genetic improvement of vital horticultural traits in radish breeding program

In recent years, Meloidogyne enterolobii has emerged as a major parasitic nematode infesting many plants in tropical or subtropical areas. However, the regions of potential distribution and the main contributing environmental variables for this nematode are unclear. Under the current climate scenario, we predicted the potential geographic distributions of M. enterolobii worldwide and in China using a Maximum Entropy (MaxEnt) model with the occurrence data of this species. Furthermore, the potential distributions of M. enterolobii were projected under three future climate scenarios (BCC-CSM2-MR, CanESM5 and CNRM-CM6-1) for the periods 2050s and 2090s. Changes in the potential distribution were also predicted under different climate conditions. The results showed that highly suitable regions for M. enterolobii were concentrated in Africa, South America, Asia, and North America between latitudes 30° S to 30° N. Bio16 (precipitation of the wettest quarter), bio10 (mean temperature of the warmest quarter), and bio11 (mean temperature of the coldest quarter) were the variables contributing most in predicting potential distributions of M. enterolobii. In addition, the potential suitable areas for M. enterolobii will shift toward higher latitudes under future climate scenarios. This study provides a theoretical basis for controlling and managing this nematode.

In Bacillus thuringenesis (Bt) transgenic cotton, the cotton boll has the lowest insecticidal protein content when compared to the other organs.  The present study investigated the effects of amino acid spray application at the peak flowering stage on the cotton boll Bt toxin concentration and yield formation.  Boll protein synthesis and carbohydrate conversion were also studied to reveal the fundamental mechanism.  Three treatments (i.e., CK, the untreated control; LA1, five amino acids; LA2, 21 amino acids) were applied to two Bt cultivars of G. hirsutum (i.e., the hybrid Sikang 3 and the conventional Sikang 1) in the cotton-growing seasons during 2017 and 2018.  Amino acid spray application at the peak flowering stage resulted in an increase of 5.2–16.4% in the boll Bt protein concentration and an increase of 5.5–11.3% in the seed cotton yield, but there was no difference between the two amino acid treatments.  In addition, amino acid applications led to increases in the amino acid content, soluble protein content, glutamate pyruvate transaminase (GPT) activity, glutamate oxaloacetate transaminase (GOT) activity, glucose content, fructose content and soluble acid invertase (SAI) activity.  This study also found that Bt protein content, enhanced boll number and the weight of opened bolls were closely related to carbon and nitrogen metabolism.  The Bt protein content had significant linear positive correlations with amino acid and soluble protein contents.  Enhanced boll number had significant linear positive correlations with the GPT and GOT activities from 15–25 days after flowering (DAF).  The weight of opened bolls from 55–65 DAF had a significant linear positive correlation with the SAI activity.  These results indicate that the enhancement of boll protein synthesis and carbohydrate conversion by amino acid application resulted in a simultaneous increase in the boll Bt protein concentration and cotton lint yield.

With the development of sequencing technology, insertions-deletions (InDels) have been increasingly reported to be involved in the genetic deter mination of agronomical traits.  However, most studies have focused on the identification and application of short-InDels (1–15 bp) for genetic analysis.  The objective of this study was to deeply deploy long-InDels (>15 bp) for the genetic analysis of important agronomic traits in soybean.  A total of 13 573 polymorphic long-InDels were identified between parents Zhongpin 03-5373 (ZP) and Zhonghuang 13 (ZH), which were unevenly distributed on 20 chromosomes of soybean, varying from 321 in Chr11 to 1 246 in Chr18.  Consistent with the distribution pattern of annotated genes, the average density of long-InDels in arm regions was significantly higher than that in pericentromeric regions at the P=0.01 level.  A total of 2 704 (19.9% of total) long-InDels were located in genic regions, including 319 large-effect long-InDels, which resulted in truncated or elongated protein sequences.  A previously identified QTL (qPH16) underlying plant height was further analyzed, and it was found that 26 out of 35 (74.3%) long-InDel markers located in the qPH16 region showed clear polymorphisms between parents ZP and ZH.  Seven markers, including three long-InDels and four previously reported SNP markers, were used to genotype 242 recombinant inbred lines derived from ZP×ZH.  As a result, the qPH16 locus was narrowed from a 960-kb region to a 477.55-kb region, containing 65 annotated genes.  Therefore, these long-InDels are a complementary genetic resource of SNPs and short-InDels for plant height and can facilitate genetic studies and molecular assisted selection breeding in soybean.

Plant height is an important agronomic trait, which is governed by multiple genes with major or minor effects.  Of numerous QTLs for plant height reported in soybean, most are in large genomic regions, which results in a still unknown molecular mechanism for plant height.  Increasing the density of molecular markers in genetic maps will significantly improve the efficiency and accuracy of QTL mapping.  This study constructed a high-density genetic map using 4 011 recombination bin markers developed from whole genome re-sequencing of 241 recombinant inbred lines (RILs) and their bi-parents, Zhonghuang 13 (ZH) and Zhongpin 03-5373 (ZP).  The total genetic distance of this bin map was 3 139.15 cM, with an average interval of 0.78 cM between adjacent bin markers.  Comparative genomic analysis indicated that this genetic map showed a high collinearity with the soybean reference genome.  Based on this bin map, nine QTLs for plant height were detected across six environments, including three novel loci (qPH-b_11, qPH-b_17 and qPH-b_18).  Of them, two environmentally stable QTLs qPH-b_13 and qPH-b_19-1 played a major role in plant height, which explained 10.56–32.7% of the phenotypic variance.  They were fine-mapped to 440.12 and 237.06 kb region, covering 54 and 28 annotated genes, respectively.  Via the function of homologous genes in Arabidopsis and expression analysis, two genes of them were preferentially predicted as candidate genes for further study.

Sugarcane has a large, complex, polyploid genome that has hindered the progress of genomic research and molecular marker-assisted selection.  The user-friendly SSR markers have attracted considerable attention owing to their ideal genetic attributes.  However, these markers were not characterized and developed at the genome-wide scale due to the previously lacking high-quality chromosome-level assembled sugarcane genomes.  In this present study, 744 305 and 361 638 candidate SSRs were identified from the genomes of S. officinarum and S. spontaneum, respectively.  We verified the reliability of the predicted SSRs by using 1 200 interspecific SSR primer pairs to detect polymorphisms among 11 representative accessions of Saccharum, including S. spontaneum, S. officinarum, S. robustum, and modern sugarcane hybrid.  The results showed that 660 SSR markers displayed interspecific polymorphisms among these accessions.  Furthermore, 100 SSRs were randomly selected to detect the genetic diversity for 39 representative Saccharum accessions.  A total of 320 alleles were generated using 100 polymorphic primers, with each marker ranging from two to seven alleles.  The genetic diversity analysis revealed that these accessions were distributed in four main groups, including group I (14 S. spontaneum accessions), group II (two S. officinarum accessions), group III (18 modern sugarcane hybrid accessions), and group IV (five S. robustum accessions).  Experimental verification supported the reliability of the SSR markers based on genome-wide predictions.  The development of a large number of SSR markers based on wet experiments is valuable for genetic studies, including genetic linkage maps, comparative genome analysis, genome-wide association studies, and marker-assisted selection in Saccharum.

Xanthomonas oryzea pv. oryzae (Xoo) is the causal agent of bacterial blight of rice, which is a significant threat to many of rice-growing regions. The type III secretion system (T3SS) is an essential virulence factor in Xoo. Expression of the T3SS is often induced in the host environment or in hrp-inducing medium but is repressed in nutrient-rich medium. The elucidation of molecular mechanism underlying induction of T3SS genes expression is a very important step to lift the veil on global virulence regulation network in Xoo. Thus, an efficient and reliable genetic tool system is required for detection of the T3SS proteins. In this study, we constructed a protein expression vector pH3-flag based on the backbone of pHM1, a most widely used vector in Xoo strains, especially a model strain PXO99^A. This vector contains a synthesized MCS-FLAG cassette that consists of a multiple cloning site (MCS), containing a modified pUC18 polylinker, and Flag as a C-terminal tag. The cassette is flanked by transcriptional terminators to eliminate interference of external transcription enabling detection of accurate protein expression. We evaluated the potential of this expression vector as T3SS proteins detection system and demonstrated it is applicable in the study of T3SS genes expression regulation in Xoo. This improved expression system could be very effectively used as a molecular tool in understanding some virulence genes expression and regulation in Xoo and other Xanthomonas spp.

Maize is one of the most important crops worldwide, but it suffers from salt stress when grown in saline-alkaline soil. There is therefore an urgent need to improve maize salt tolerance and crop yield. In this study, the SsNHX1 gene of Suaeda salsa, which encodes a vacuolar membrane Na⁺/H⁺ antiporter, was transformed into the maize inbred line 18-599 by Agrobacterium-mediated transformation. Transgenic maize plants overexpressing the SsNHX1 gene showed less growth retardation when treated with an increasing NaCl gradient of up to 1%, indicating enhanced salt tolerance. The improved salt tolerance of transgenic plants was also demonstrated by a significantly elevated seed germination rate (79%) and a reduction in seminal root length inhibition. Moreover, transgenic plants under salt stress exhibited less physiological damage. SsNHX1-overexpressing transgenic maize accumulated more Na⁺ and K⁺ than wild-type (WT) plants particularly in the leaves, resulting in a higher ratio of K+/Na+ in the leaves under salt stress. This result revealed that the improved salt tolerance of SsNHX1-overexpressing transgenic maize plants was likely attributed to SsNHX1-mediated localization of Na⁺ to vacuoles and subsequent maintenance of the cytosolic ionic balance. In addition, SsNHX1 overexpression also improved the drought tolerance of the transgenic maize plants, as rehydrated transgenic plants were restored to normal growth while WT plants did not grow normally after dehydration treatment. Therefore, based on our engineering approach, SsNHX1 represents a promising candidate gene for improving the salt and drought tolerance of maize and other crops.

As abiotic stresses become more severe as a result of global climate changes, the growth and development of plants are restricted. In the development of agricultural crops with greater stress tolerance, AmDUF1517 had been isolated from the highly stress-tolerant shrub Ammopiptanthus mongolicus, and can significantly enhance stress tolerance when inserted in Arabidopsis thaliana. In this study, we inserted this gene into cotton to analyze its potential for conferring stress tolerance. Two independent transgenic cotton lines were used. Southern blot analyses indicated that AmDUF1517 was integrated into the cotton genome. Physiological analysis demonstrated that AmDUF1517-transgenic cotton had stronger resistance than the control when treated with salt, drought, and cold stresses. Further analysis showed that trans-AmDUF1517 cotton displayed significantly higher antioxidant enzyme (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione S-transferase (GST)) activity and less reactive oxygen species (ROS) accumulation, which suggests that overexpression of AmDUF1517 can improve cotton resistance to stress by maintaining ROS homeostasis, as well as by alleviating cell membrane injury. These results imply that AmDUF1517 is a candidate gene in improving cotton resistance to abiotic stress. 

Chalcone synthases (CHS, EC 2.3.1.74) are key enzymes that catalyze the first committed step in flavonoid biosynthesis. In this study, we isolated a chalcone synthase, named NtCHS6, from Nicotiana tabacum.  This synthase shared high homology with the NSCHSL (Y14507) gene and contained most of the conserved active sites that are in CHS proteins.  The phylogenetic analysis suggested that NtCHS6 protein shared a large genetic distance with other Solanaceae CHS proteins and was the most closely-related to an uncharacterized CHS from Solanum lycopersicum.  The expression analysis indicated
that NtCHS6 was abundantly expressed in leaves, especially in mature leaves.  By scrutinizing its upstream promoter sequences, multiple cis-regulatory elements involved in light and drought responsive were detected.  Furthermore, NtCHS6 expression decreased significantly under dark treatment and increased significantly under drought stress.  Our results suggested that NtCHS6 expression exhibited both light responsiveness and drought responsiveness, and might play important roles in ultraviolet protection and drought tolerance.

Curvularia leaf spot, caused mainly by Curvularia lunata, is a widespread plant disease in China.  In the recent years, directional host selection by the pathogen, which likely results in the virulence differentiation in pathogens, is widely reported.  Among the hallmarks potentially associated to pathogen variation in virulence, superoxide dismutase gene Sod has been found to be closely related to the enhancement of virulence.  In the present study, the full-length of Sod was obtained via Blastn alignment against GenBank and the whole genome of C. lunata.  In order to understand the role of Sod in the virulence variation in C. lunata, targeted gene disruption was performed to construct Sod mutants.  The cell wall degrading enzyme (CWDE) activities and toxin production of ΔSod were not distinctly different from wild-type strain CX-3 and its complon.  However, at an early stage of infection, ΔSod virulence appeared to be lower than CX-3 and the complon, while at a later stage, its virulence gradually returned to the level of CX-3 and the complon.  Furthermore, the melanin production of ΔSod was significantly reduced compared to CX-3 and the complon, suggesting that Sod gene influences the virulence by regulating melanin production at an early stage of infection but is not essential for pathogenicity.  However, the disruption of Sod did not significantly affect the transcriptional expression of the melanin biosynthesis-associated genes, brn1 and scd.  Therefore, we infer that Sod in C. lunata are involved, to some extent, with the virulence in maize leaf, but still needs further studies to have a clear understanding of its mechanism.

Nutrient deficiency stresses often occur simultaneously in soil.  Thus, it’s necessary to investigate the mechanisms underlying plant responses to multiple stresses through identification of some key stress-responsive genes.  Quantitative real-time PCR (qRT-PCR) is essential for detecting the expression of the interested genes, of which the selection of suitable reference genes is a crucial step before qRT-PCR.  To date, reliable reference genes to normalize qRT-PCR data under different nutrient deficiencies have not been reported in plants.  In this study, expression of ten candidate reference genes was detected in leaves and roots of rapeseed (Brassica napus L.) after implementing different nutrient deficiencies for 14 days.  These candidate genes, included two traditionally used reference genes and eight genes selected from an RNA-Seq dataset.  Two software packages (GeNorm, NormFinder) were employed to evaluate candidate gene stability.  Results showed that VHA-E1 was the highest-ranked gene in leaves of nutrient-deficient rapeseed, while VHA-G1 and UBC21 were most stable in nutrient-deficient roots.  When rapeseed leaves and roots were combined, UBC21, HTB1, VHA-G1 and ACT7 were most stable among all samples.  To evaluate the stabilities of the highest-ranked genes, the relative expression of two target genes, BnTrx1;1 and BnPht1;3 were further determined.  The results showed that the relative expression of BnTrx1;1 depended on reference gene selection, suggesting that it’s necessary to evaluate the stability of reference gene prior to qRT-PCR.  This study provides suitable reference genes for gene expression analysis of rapeseed responses to different nutrient deficiencies, which is essential for elucidation of mechanisms underlying rapeseed responses to multiple nutrient deficiency stresses.

Agrobacterium-mediated transient expression assays are a convenient alternative to stable expression because they are simple, easy to perform, and achieve gene expression rapidly.  This study investigated the factors affecting transient gene expression efficiency in citrus by observing the cryo-sectioning of leaf samples under a laser confocal microscope.  These factors included the composition of the infiltration buffer, the Agrobacterium cell density, the leaf development stage, the incubation temperature, and plant genotype.  The highest transient expression level of yellow fluorescent protein (YFP) was detected in Mexican lime (Citrus aurantifolia) on the third day after the intermediate-aged leaves were infiltrated with the improved infiltration buffer 1 (15 mmol L^-1 2-(N-morpholino) ethanesulfonic acid, 10 mmol L^-1 MgCl₂, and 200 μmol L^-1 acetosyringone), which had an optical density of 0.8 and was incubated at 22°C.  Additionally, this transient expression assay was applied to other citrus genotypes.  Of note, trifoliate orange (Poncirus trifoliata) and kumquat (Fortunella obovate) had higher expression efficiency than other six genotypes of the Citrus genus.  Our study provides research basis for the selection of optimization strategies in transient gene expression and improves the method for available genome investigation in citrus.

The cultivated soybean (Glycine max (L.) Merr.) was distinguished from its wild progenitor Glycine soja Sieb. & Zucc. in growth period structure, by a shorter vegetative phase (V), a prolonged reproductive phase (R) and hence a larger R/V ratio. However, the genetic basis of the domestication of soybean from wild materials is unclear. Here, a panel of 123 cultivated and 97 wild accessions were genotyped using a set of 24 presence/absence variants (PAVs) while at the same time the materials were phenotyped with respect to flowering and maturity times at two trial sites located at very different latitudes. The major result of this study showed that variation at PAVs is informative for assessing patterns of genetic diversity in Glycine spp. The genotyping was largely consistent with the taxonomic status, although a few accessions were intermediate between the two major clades identified. Allelic diversity was much higher in the wild germplasm than in the cultivated materials. A significant domestication signal was detected at 11 of the PAVs at 0.01 level. In particular, this study has provided information for revealing the genetic basis of photoperiodism which was a prominent feature for the domestication of soybean. A significant marker-trait association with R/V ratio was detected at 14 of the PAVs, but stripping out population structure reduced this to three. These results will provide markers information for further finding of R/V related genes that can help to understand the domestication process and introgress novel genes in wild soybean to broaden the genetic base of modern soybean cultivars.

Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Leaves, especially the flag leaves, as CHA initial recipients play a decisive role in inducing male sterility. To investigate effects of different treatment times of CHA-SQ-1 used, morphological, biochemical and physiological responses of wheat flag leaves were detected in this study. CHA induced programmed cell death (PCD) as shown in terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) and DNA laddering analysis. In the early phase, CHA-SQ-1 triggered organelle changes and PCD in wheat leaves accompanied by excess production of reactive oxygen species (O2 -. and H2O2) and down-regulation of the activities of superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD). Meanwhile, leaf cell DNAs showed ladder-like patterns on agarose gel, indicating that CHA-SQ-1 led to the activation of the responsible endonuclease. The oxidative stress assays showed that lipid peroxidation was strongly activated and photosynthesis was obviously inhibited in SQ-1-induced leaves. However, CHA contents in wheat leaves gradually reduced along with the time CHA-SQ-1 applied. Young flags returned to an oxidative/antioxidative balance and ultimately developed into mature green leaves. These results provide explanation of the relations between PCD and anther abortion and practical application of CHA for hybrid breeding.

The adaptability of soybean to be grown at a wide range of latitudes is attributed to natural variation in the major genes and quantitative trait loci (QTLs) that control flowering time and maturity. Thus, the identification of genes controlling flowering time and maturity and the understanding of their molecular basis are critical for improving soybean productivity. However, due to the great effect of the major maturity gene E1 on flowering time, it is difficult to detect other small-effect QTLs. In this study, aiming to reduce the effect of the QTL, associated with the E1 gene, on the detection of other QTLs, we divided a population of 96 recombinant inbred lines (RILs) into two sub-populations: one with the E1 allele and another with the e1nl allele. Compared with the results of using all 96 recombinant inbred lines, additional QTLs for flowering time were identified in the sub-populations, two (qFT-B1 and qFT-H) in RILs with the E1 allele and one (qFT-J-2) in the RILs with the e1nl allele, respectively. The three QTLs, qFT-B1, qFT-H and qFT-J-2 were true QTLs and played an important role in the regulation of growth period. Our data provides valuable information for the genetic mapping and gene cloning of traits controlling flowering time and maturity and will help a better understanding of the mechanism of photoperiod-regulated flowering and molecular breeding in soybean.

An efficient plant regeneration protocol was established for castor bean (Ricinus communis L.), in which 0.3 mg L^–1 thidiazuron (TDZ) induced shoot clusters and increased the number of adventitious shoots from hypocotyl tissue. Our results showed that treatment under dark conditions significantly promoted the average number of shoots per explant to 37.36±4.54 (with a 6-d treatment). Modified 1/2 Murashige and Skoog (MS) basal medium supplemented with 440 mg L^–1 Ca²⁺, 0.2 mg L^–1 gibberellic acid and 0.1 mg L^–1 TDZ significantly increased shoot elongation rates and lowered vitrification rates. Furthermore, 1/2 MS media supplemented with 0.2 mg L^–1 1-naphthaleneacetic acid induced a higher rooting rate compared with other culture conditions.

Nitrogen (N) is one of the macronutrients required for plant growth, and reasonable application of N fertilizers can increase crop yields and improve their quality. However, excessive application of N fertilizers will decrease N use efficiency and also lead to increases in N2O emissions from agricultural soils and many other environmental issues. Research on the effects of different N fertilizer management practices on wheat yields and N2O emissions will assist the selection of effective N management measures which enable achieving high wheat yields while reducing N2O emissions. To investigate the effects of different N management practices on wheat yields and soil N2O emissions, we conducted field trials with 5 treatments of no N fertilizer (CK), farmers common N rate (AN), optimal N rate (ON), 20% reduction in optimal rate+dicyandiamide (ON80%+DCD), 20% reduction in optimal rate+nano-carbon (ON80%+NC). The static closed chamber gas chromatography method was used to monitor N2O emissions during the wheat growing season. The results showed that there were obvious seasonal characteristics of N2O emissions under each treatment and N2O emissions were mainly concentrated in the sowing- greening stage, accounting for 54.6–68.2% of the overall emissions. Compared with AN, N2O emissions were decreased by 23.1, 45.4 and 33.7%, respectively, under ON, ON80%+DCD and ON80%+NC, and emission factors were declined by 22.2, 66.7 and 33.3%, respectively. Wheat yield was increased significantly under ON80%+DCD and ON80%+NC by 12.3 and 11.9%, respectively, relative to AN while there was no significant change in yield in the ON treatment. Compared with ON, overall N2O emissions were decreased by 29.1 and 13.9% while wheat yields improved by 18.3 and 17.9% under ON80%+DCD and ON80%+NC, respectively. We therefore recommend that ON80%+DCD and ON80%+NC be referred as effective N management practices increasing yields while mitigating emissions.

The novel cry1Ai gene that cloned from Bacillus thuringiensis strain SC6H8 encoded a protein exhibiting strong toxicity against Plutella xylostella and Chilo suppressalis in our previous study. Using the available information for the active fragments of other Cry toxins, eight truncated fragments were constructed to identify the minimal active fragment of Cry1Ai. All truncated fragments were expressed in Escherichia coli strain BL21 (DE3), and the insecticidal activity against 2nd- instar P. xylostella larvae was assessed using full-length Cry1Ai as a positive control. The results indicate that the minimal active fragment of the Cry1Ai toxin against P. xylostella is located between amino acid residues 36I and 605I, which is smaller than the regions previously reported for Cry1A. The first two amino acids (34T and 35P) on helix α-1 and whole helix α-2 of domain I and sheet β-32 of domain III are necessary for Cry1Ai toxin to keep its toxicity against P. xylostella.

In order to establish double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) for detection of duck or goose flavivirus, polyclonal antibody against the flavivirus strain JS804 in geese and monoclonal antibody against the E protein of flavivirus strain JS804 in geese were used as the capture antibody and detection antibody, respectively. The optimal dilution of the capture antibody and detecting antibody capable of detecting the flavivirus strain JS804 in geese were 1:3 200 and 1:160 in the check-board titration, respectively. The reaction time of sample was 1 h, and the optimal working dilution of HRP-labeled goat-anti-mouse IgG was 1:10 000. The positive standard value was 0.247 (OD450 nm). The geese flavivirus could be detected at a minimal concentration of 1.875 μg mL-1. The ELISA had no cross-reaction with Newcastle disease virus (NDV), Avian influenza virus (AIV), Infectious bronchitis virus (IBV), Infectious bursal disease virus (IBDV), Duck hepatitis virus (DHV), and Gosling plague virus (GPV). Twenty clinical samples were detected by the DAS-ELISA and RT-PCR respectively, with the agreement rate of 75%. The results revealed that the DAS-ELISA possessed favorable specificity and higher sensitivity, indicating a suitable method for rapid detection of the duck or goose flavivirus.