One of main reasons for rejection of manuscript written by Chinese scientists by international journals is the inadequate or incorrect statistical data analysis. Over the last two decades, there have been significant developments in statistical methodology and implementation of statistics as computer software. However, most plant pathologists in China are still using conventional ANOVA or ordinary analysis for types of data that should be analyzed by more appropriate methods. In this short paper, we briefly introduce some statistical methods that are most likely to be appropriate for common data types encountered in plant pathology. We hope this would enable researchers to read more in a particular topic and to collaborate with applied statisticians.

The full length cDNA (MeHsp70) of Hsp70 from Meloidogyne enterolobii was cloned by using RT-PCR, rapid amplification of cDNA ends ( RACE) . The full-length cDNA of MeHsp70 was 2 203 bp containing an open reading frame (ORF) of 1 959 bp encoding a polypeptide of 653 amino acids with a predicted molecular mass of 71.09 kDa, which carried three important and intact Hsp70 signature sequences, which was registered in GenBank with accession No. KF739434. The result of sequence similarity-analysis revealed that the translated molecules showed high homology to other eukarya. The Hsp70s phylogenetic analysis showed that the phylogenetic tree could not reflect the genetic relationship of the organisms, maybe similarity of biological functions was revealed. The complete ORF encoding MeHsp70 was inserted into pEASY-E1 and an expression vector pEASY-E1-MeHsp70 was constructed. The MeHsp70 protein was induced to express by 0. 4-1.0 mmol/L IPTG. This study provided theoretical basis supporting research on mechanisms of the ecological adaptability of M. enterolobii.

Arceuthobium sichuanense, a hemiparasitic plant, is the most destructive pathogen of natural and man-made spruce forest in China. First report of A. sichuanense infection in Picea wilsonii trees in Qinghai province, China was released in this study, and the morphological characters of needles, diurnal changes of photosynthesis and transpiration in healthy and infected P. wilsonii trees were investigated. It was shown that the length and width of needles from the infected P. wilsonii were significantly smaller than those from control trees (P＜0.001), but the specific leaf area (SLA) of diseased P. wilsonii was significantly bigger than that of control trees (P＜0.001). Furthermore, infection by A. sichuanense significantly reduced net photosynthesis rate (P_n), transpiration rate (T_r) and stomatal conductance (G_s) of P. wilsonii trees (P＜0.05). However, substomatal CO₂ concentration (C_i) was not influenced by A. sichuanense infection (P=0.32). Relationship analysis between environmental factors and photosynthesis-transpiration of P. wilsonii trees based on redundancy analysis (RDA) revealed that the importance of the tested environmental factors were changed by A. sichuanense infection, from ambient CO₂ concentration (CO₂)＞air temperature (T_air)＞leaf temperature (T_l)＞vapor pressure deficit (Vpd)＞air relative humidity (RH)＞photosynthetic active radiation (PAR) for control trees to T_l＞RH＞T_air＞PAR＞Vpd＞CO₂ for diseased trees. T_l became the key factor affecting P_n and T_r of diseased P. wilsonii trees. The P_n and T_r of diseased P. wilsonii trees also became more sensitive to RH and PAR. Moreover, water use efficiency (WUE) of diseased trees was significantly lower than that of control trees (P＜0.05). Therefore, infection by A. sichuanense would weaken the adaptive capacity of P. wilsonii to environment and accelerate the death of the trees.

Resistance system induced by Fusarium oxysporum f. sp. niveurn in watermelon was described from the whole level, and expression characteristics of the related genes were analyzed. “Calhoun Gray”, a watermelon variety with high resistance to Fusarium wilt physiological race 1 was used as the test material, and a cDNA library was constructed by suppression subtractive hybridization (SSH) using root tip tissues sampled at 0、6、12、24、36、48 and 72 h after inoculation with race 1 of F. oxysporum f. sp. niveurn or distilled water. The induced clones were verified by reverse Northern dot-blot, and 300 positive clones were randomly sequenced, and the expression of two important genes was studied by RT-PCR. A total of 259 differentially expressed sequences were screened out, and 167 of them were quite similar to the known genes, accounting for 65.5%; Among of them, 64 genes are related to disease resistance and defense, accounting for 24.7%. Blast results showed that the resistance related genes of Calhoun Gray included signal transduction, disease defense, transcription factor, secondary metabolism synthesis, plant cell protection, etc. Further analysis indicated that expression of aquaporin and peroxidase genes were both increased after inoculation with Fusarium wilt physiological race 1. The interaction between Calhoun Gray and F. oxysporum involves many aspects, which is similar to that of PI296341. The resistance related genes are mainly those participating in systemic acquired resistance reaction, and genes exclusively expressed in Calhoun Gray but not in PI296341 were gained. These results make a good foundation for further exploration of molecular mechanism between watermelon and F. oxysporum and identification of the key resistant genes.

Bacterial fruit blotch of melons caused by Acidovorax citrulli(Schaad et al.2008) is a world-wide disease and gives rise to serious damages on the cucurbits plants. Strain Aac5 isolated from watermelon was a mutant constructed with an inner inserted deletion of hrcN gene by using homologous recombination. This mutant strain was confirmed by PCR and Southern blot. The mutant displayed reduces in virulence, hypersensitive reaction, quorum sensing, growth ability and motility compared to wild type. All these phenotype changes could be partially restored through complement mutant by introducting hrcN. In order to understand the regulation relationships between hrcN and other related genes, three genes(hrpA,hrcV,hrcU)related to pathogenicity,two genes (LuxI, LuxR)related to quorum sensing and a housekeeping gene(pilT) were selected to determine the expression by Real-Time qPCR. The results showed that the expressions of five selected genes in mutant strains were increased compared to the wild type. Thus the relationship between hrcN and five selected genes displayed a negative regulation. All the results showed that hrcN gene played an important role in pathogenicity of Acidovorax citrulli.

New virulences to Chinese stripe rust differentials cv. Guinong 22,collected from Pi County, Sichuan Province, China, were reported, whose important traits were virulent to Yr10 and Yr26 which were effective genes to Chinese stripe rust populations in China. The virulence spectrum to International and European differentials was tested. The new isolate CM42-3 was designated 82E8 with virulence formula (avirulence/virulence) 1、3、4、5、11、15、17、18、25、27、28、31、32、Sd、Sk、Sp/2、6、7、8、9、10、24、26、29、30, Su. And CY33 was named 43E190 by the international nomenclature of physiologic races with virulence formula 5、10、15、24、26、27、Sk、Sp/1、2、3、4、6、7、8、9、11、12、17、18、25、28、29、30、31、32、A、Su. The pathogenicity to 115 bread wheat cultivars was carried out, indicating the potential threat of 82E8 to Chinese winter wheat varieties. In addition, the reasonable strategy of deployment of Yr10 and Yr26 was discussed.

Stripe rust, caused by Puccinia striiformis f.sp. tritici (Pst), is one of the most devastating diseases of wheat throughout the world. Tianxuan 43, a wheat cultivar derived from hybridization between 8845-01-01-1-1 and Guinong 22, is resistant to the current prevalent Pst races in China. To identify and map the gene(s) conferring resistance to stripe rust, Pst races including CYR32 and CYR33 were selected to test the F₁,F₂and F₃ generations derived from the cross Tianxuan 43/Mingxian 169 at seedling stage. SSR (simple sequence repeat) markers were used to map the gene conferring resistance to CYR32. The genetic analysis showed that one dominant resistance gene to CYR32 and one recessive resistance gene were estimated for Tianxuan 43. By using SSR to analyze the 150 individuals in the F₂ segregating population, ten markers on chromosome 1BS including Xwmc134, Xgwm413, Xbarc187, Xwmc406, Xcfd65, Xgwm18, Xbarc181, Xbarc137, Xwmc419 and Xgwm230, were identified to be linked with the resistance gene YrTx43 (temporarily designated). The two closest linked flanking markers were Xgwm18 and Xgwm413 with genetic distances of 0.8 and 3.4 cM, respectively. According to origin, chromosome location and molecular detection, YrTx43 could be allelic to stripe rust resistance genes Yr24 and Yr26.

In this study, we obtained a GmDRRP (glycine max disease resistance response protein) gene from soybean microarray data, and functionally characterized roles of its promoter during Phytophthora sojae infection. Phylogenetic and functional domain analysis showed that this gene encoded a soybean DRRP protein. qRT-PCR analysis indicated it was down-regulated by the tested hormones. Then, a promoter fragment harboring the -1,590 to +1 region (the transcription start site of GmDRRP is defined as +1 position) was isolated from soybean (cv. Williams). Its activity was determined by both transient expression assay in Nicotiana benthamiana and stable expression in transgenic soybean hairy roots. The results showed that GmDRRP promoter-derived Gus expression was rapidly induced at 0.5 hpi (hours post infection), and reached high levels at 2 hpi. We also identified a 222 bp fragment that was important for its full activities by deletion analysis. Thus, we provide a promoter that can confer Phytophthora-induced expression.

Dongnong415 is well known for early maturity, diseases resistance and high yield since breeding, and has a high level blast resistance after cultivating more than 20 years in high incidence area of rice blast in Heilongjiang province. The evaluation of Dongnong415 for its resistance against 158 blast isolates collected from different rice cultivated regions of Heilongjiang province showed that this cultivar can resist 89.2% of all tested isolates, indicating that Dongnong415 has a broad-spectrum blast resistance. F-10-11 was used as the test isolate, and the genetic analysis of Dongnong415 by inoculating F₁ and F₂ populations derived from a cross of Dongnong415×LTH, showed that the resistance of Dongnong415 to the isolate was controlled by a single dominant gene. We constructed a mapping population consisting of 99 susceptible F₂ plants to isolate F-10-11. The resistance gene of Dongnong415, temporarily named as Pi-dn(t), was mapped at a region beween RM213 and RM5300 with 3.0 and 7.6 cM genetic distances in chromosome 2 based on molecular markers and BSA-RCA strategy. Pi-dn(t) loci were mapped in rice reference genome, and three coding genes with the domain structure of disease resistance Os02g56010, Os02g55540 and Os02g56400 were founded in the genome segment of resistance loci. The three genes can be used as resistant candidate genes for Pi-dn(t).

In order to find the measure to control the Fusarium wilt disease of banana, effects of ammonium (NH₄⁺-A) and nitrate (NO₃^--N) applications were studied on disease index, chlorophyll content, gas exchange parameters, pathogen distribution, concentrations of Ca, Mg, Fe and Mo, soluble carbohydrate content and lignin content of banana seedlings grown with pot experiment and infected by Fusarium oxysporum f. sp. cubense (FOC). The results showed no difference in growth of banana seedlings between two forms of nitrogen treatment. However, after pathogen inoculation, compared with ammonium treatment, nitrate treatment could significantly reduce the pathogen levels in various plant organs as well as disease incidence and disease severity. Pathogen challenge reduced plant photosynthetic rate under both nitrogen treatment conditions. Nitrate treatment maintained a relative higher photosynthetic rate compared than the ammonium treatment. Nitrate treatment significantly enhanced the contents of Ca, Mg, Fe and Mo in plant after FOC infection. The content of leaf soluble carbohydrate was not affected by either treatment, but the root carbohydrate content was reduced in nitrate treated banana seedlings. Lignin content was relatively stable in ammonium treatment, whereas it increased significantly in nitrate treatment following pathogen infection. It was concluded that the effect of nitrate treatment on enhanced disease resistance of banana plants was probably due to the elevated absorption of resistance-related nutrients which induced the synthesis of lignin and the enhanced lignification therefore maintaining a higher photosynthetic rate and high disease resistance.

The root rot disease of Chinese jujube is one of the important restricting factors affected jujube industry in Xinjiang. Pathogen identification showed that three kinds of fungal pathogens were associated with Chinese jujube root rot.They were Fusarium species including F. oxysporum, F. solani, Pythium aphanidermatum and Rhizoctonia solani.

A new blight disease was found on konjac and caused severity loss in Fuyuan County, a main konjac production area in Yunnan. The purified isolates were determined for pathogenicity with Koch’s postulates and sequenced based on two targets, ribosomal DNA-ITS and Cox2. The phylogenetic relationships between the pathogen and Phytophthora species were also analyzed. The results showed that the isolates were the new pathogen of konjae. The pathogen formed white colony on clarified V8 agar and the hypha were observed without septum, producing spherical chlamydospores and forming ovoid or obpyriform sporangia with obvious papillate. Both DNA sequences of rDNA-ITS and Cox2 from the pathogen shared the highest similarity and had 99% homology with known Phytophthora nicotianae. The phylogenetic tree also showed both the pathogen and P. nicotianae were clustered in the same sub-group. These results confirmed that the pathogen caused blight disease on konjac was P. nicotianae. According to our knownledge, this is the first report of new host of P. nicotianae and new disease of konjac.

Plant defense against viruses through small RNA (sRNA) mediated RNA interference mechanism. Analysis of virus derived sRNA profiles in plant can be applied for de novo assembly of virus genomes and virus identification. In this study, suspected virus-infected Wisteria sinensis samples collected from Zijingang Campus of Zhejiang University were used for sRNA library construction and deep sequencing. After assembly of total sRNAs, it was found that W. sinensis leaves were infected by Wisteria vein mosaic virus (WVMV). The library generated 18.9 million sRNA reads, of which 0.32 million were WVMV-derived sRNAs. Using de novo assembly, 23.3% of full length genome nucleotide sequence of a previously reported potyvirus WVMV was obtained. To confirm the existence of WVMV in the samples, WVMV coat protein (CP) gene sequence was obtained by RT-PCR, and ensured by Sanger sequencing. Taken together, the data suggest that sRNA deep sequencing technology is an efficient and powerful genetic tool for virus identification in woody plants.

In order to develop a new method for the detection of Phytophthora capsici, a set of primers for loop-mediated isothermal amplification (LAMP) were designed basing on the Ras-related protein-coding gene (PcYpt1) sequences. The specificity of the LAMP primers was assessed against P. capsici isolates, closely related Phytophthora spp., Pythium spp. and other fungi. The results showed that only P. capsici gave positive reaction, and all of other tested species gave negative reactions. The detection limit of the LAMP assay with the PcYpt1 primers was 100 pg/μL P. capsici genomic DNA. Thus, the PcYpt1-LAMP assay could be used as a reliable, rapid and cost-effective detection method for the pathogen P. capsici in field-grown pepper plants and production fields.

Plant obtains immunity against RNA virus through small interference RNA (siRNA) mechanism. we adopt next-generation sequencing technology to perform high throughput sequencing of tabacco siRNA and screening for RNA virus sequences with bioinformatics methods. We found that PVY, CMV, TMV, TVBMV and other virus genomic information in Anhui Province. This research established a new strategy to find naturally RNA viruses in tobacco, and this strategy could be applied to virus surveillance in tobacco.

Rice black-streaked dwarf virus (RBSDV) is the main pathogen that causes maize rough dwarf, rice black-streaked dwarf and wheat green dwarf in China, leading to severe damage of crop yield and quality. In this study RBSDV infected maize leaves were collected from eight areas in Henan province. RT-PCR was conducted to amplify the full-length s10 gene for sequencing. The results showed that the s10 of all the eight isolates were 1 801 bp in length which encoded a protein of 558 amino acids (aa). The nucleotide and amino acid homology among the eight isolates were 93.0%～99.88% and 98.20%～99.80%, respectively, indicating that the variation of nucleotides was more obvious than that of amino acids.

Bioactive metabolites produced by Pichia anomala 0732-1 displayed significant antibacterial activity to Acidovorax avenae subsp. citrulli (Aac) which caused bacterial fruit blotch. The antibiotic capacity, antibacterial activity and stability of crude antagonistic extract of P. anomala 0732-1 were tested and the active substances were isolated. The results showed that the antibacterial material was not sensitive to ultraviolet radiation and temperature, and it was stable at pH<9. The antibacterial material was purified by precipitation with (NH₄)₂SO₄ (10%-100%, w/v), extraction with benzene, acetone, chloroform, phenixin, ethanol and ethyl acetate, and distillation method. However, it could not be purified by precipitation with (NH₄)₂SO₄ or by extraction with organic solvent. It could be partially distilled out by distillation. In addition, antibacterial substances produced by P. anomala 0732-1 had significant inhibitory effect against Hami melon seed infested by Aac (bacterial suspension 1×10⁸ CFU/mL). When infected seeds were treated with crude antagonistic extract of P. anomala 0732-1 for 120 min, the seeding disease index was 1.67 during the cotyledon. This study suggested that P. anomala 0732-1 had the potential to be developed as an antagonistic agent for control Hami bacterial fruit blotch.

Jujube witches’ broom phytoplasma (JWB) collected from Shandong Province was identified and the sequence polymorphism of some typical genes was then analyzed. Four different types of universal primer pairs of phytoplasma were used to amplify 1.4 kb fragment of 16S rRNA, 1.2 kb fragment of rp gene, 0.8 kb fragment of secA gene, 1.4 kb fragment of secY gene, and the secA gene was first amplified from jujube witches’ broom phytoplama. The PCR-amplified products were sequenced and compared with the related sequences of phytoplasmas in NCBI. The results of phylogenetic analysis showed that jujube witches’ broom phytoplasmas collected in Shandong belong to subgroup 16SrⅤ-B、rpⅤ-C、secYⅤ-C. Analysis of sequence polymorphism revealed rp, secA and secY contain more non-synonymous mutations and are more variable than 16S rRNA gene, indicating their suitable use for finer differentiation of diverse strains of the jujube witches’ broom phytoplasmas from China.

Pine wilt disease primarily caused by pine wood nematode, Bursaphelenchus xylophilus is a disease complex involved with a series of biotic factors, including vector beetles, host pines, tree-inhabitant fungi and associated bacteria, which directly impacts the life cycle of the nematode and contributes to the wilt syndrome to some extent. Three strains of two dominant fungi isolated from the infected Pinus massoniana forests in eastern China, Zhejiang Province, were tested as the potential food for propagation of the nematode, B. xylophilus, and the effect of these tree-inhabitant fungi on the formation of dispersal larvae of the nematode were also evaluated during the pupation and eclosion of Monochamus alternatus in mimic pupal chambers. The results showed that the third-stage dispersal juveniles (J_Ⅲ) of the nematode were mainly carried by the pupae stage of the beetles on the body surface; and the fourth-stage dispersal juveniles (J_Ⅳ) of the nematode were carried by the eclosed beetles inside their bodies. Of the three strains, Pestalotiopsis microspora M32 could increase the nematode population to its highest level and the inoculated chambers contained the beetles with the highest amounts of dispersal juveniles. In comparison, two strains of Sphaeropsis sapinea, E11 and MHS7.3 could only maintain the nematode population at lower levels and the dispersal juveniles carried by the treated beetles were also at lower levels. The proportion of the dispersal nematodes (J_Ⅲ＋J_Ⅳ) in total nematodes in M32 treatment was much lower than that in E11 and MHS7.3 treatments, indicating the unsuitable fungi induced the conversion of the nematodes from propagative forms to dispersal forms. J_Ⅳ first appeared two days after the beetle pupation and then dramatically increased at the beginning of eclosion. J_Ⅲ reached to peak before eclosion in P. microspora inoculation predicted the large amount of J_Ⅲ might be necessary for them to molt to J_Ⅳ. We concluded that the tree-inhabitant fungi can significantly impact the spread efficiency of B. xylophilus vectored by M. alternatus, which on the other hand provides a new insight for the disease management.

Xanthomonas oryzae pv. oryzae (Xoo), causes bacterial leaf blight (BLB) in rice (Oryza sativa), which is one of the most serious bacterial diseases in rice. The Xoo-rice pathosystem mainly depends on a type III secretion system (T3SS) encoded by a hrp gene cluster to inject T3SS effectors (T3SEs) into rice cells for BLB disease development. HrpG is a major regulator to control the expression of hrp genes. To determine unknown regulators controlling the expression of hrpG, four mutants G24-46, G48-22, G19-14 and G57-41 were screened from a transposon-inserted library of Xoo by using a hrpG∷gusA fusion as a reporter. The results from GUS activity assays, real-time quantitative PCR and an in situ GUS staining experiment demonstrated that the hrpG expression in these four mutants was dramatically increased when compared to the wild-type strain. Southern blotting and sequencing analysis showed that the single transposon was inserted in minD, pilA, metB and woxB genes, in the mutants G24-46, G48-22, G57-41 and G19-14, respectively. Virulence assays displayed that the mutation in these four genes led the pathogen less virulent in rice compared to the wild-type. Therefore, identification of these hrpG regulator genes would provide some new threads to elucidate the regulation network upstream the hrpG gene in X. oryzae.

Xanthomonas campestris pv. campestris 8004 (Xcc 8004) is a Gram-negative bacterium that undergoes a complex developmental life cycle. It is the causal agent of black rot disease of cruciferous plants. The genome annotation has demonstrated the presence of a significant number of these being putative two-component signal transduction system (TCS) protein. This study used bioinformatics methods to identify sensor kinase and response regulator genes. The analysis revealed the presence of 111 TCS genes, in which 30 of 55 sensor kinase genes lay adjacent to genes encoding response regulators. It strongly suggested that these paired genes encode putative TCSs. There were 25 orphan sensor kinase and 26 response regulator genes encoded in the genome. In addition we found 3 HKs and 2 RRs which were not annotated before. This article attempts to infer useful information for functional two-component regulatory system of Xcc 8004 and disease prevention and control.

To elucidate whether the flagellin (FliCxcv) from Xanthomonas campestris pv. vesicatoria(Xcv) act as a PAMP to induce PTI (PAMP-triggered-immunity) in rice, the gene cloning, sequence analysis, prokaryotic expression, protein purification and PAMP activity assay of FliCxcv and truncated proteins were performed in this study. The results show that the fliCxcv gene was cloned through PCR specific amplication from the genomic DNA of Xcv strain XV18, the sequence of which is identical to that of the sequenced strain in the GenBank. Moreover, the full-length, N- and C-terminal domains were expressed in Escherichia coli respectively and purified to get FliCxcv and truncated proteins FliCxcv-N and FliCxcv-C. The immunity responses including hypersensitive cell death, H₂O₂ production and expression of defense-related genes, such as OsPAL and OsPR1b were observed in rice leave tissues infiltrated by these purified proteins. These results suggested that Xcv flagellin was an effective PAMP to elicit PTI in rice, which can be used for the development of novel inducing agent of rice disease resistance.

Based on Chinese race differentials varieties, 257 Magnaporthe oryzae strains that isolated from Jiangsu and Liaoning Province were identified and categorized into 23 physiological races in 7 groups, in which Jiangsu isolates had 12 physiological races in 5 groups and Liaoning isolates had 21 physiological races in 7 groups. The frequency of dominant races ZG1 and ZC15 were 30.84% and 19.63% in Liaoning population; While it was 52.92% for Jiangsu dominant race ZG1. The Tsunematru mono-resistance gene lines from Japan differentiated Jiangsu and Liaoning strains into 37, 46 races respectively. In Jiangsu population the frequencies of dominant races 011, 011.2 and 000 were 25.33%, 14.67% and 12.67%, respectively; While it was 28.97% for Liaoning dominant race 011.2. Based on LTH-NILs Jiangsu and Liaoning strains can be categorized into 27 and 23 pathogenic types, respectively. Evaluation by Pot2-rep-PCR and setting the similarity at 75%, the genetic diversity of the tested strains can be categorized into 13 lineages, among which there were 12 in Jiangsu and 6 in Liaoning. The frequencies of dominant lineages L11, L12 and L4 in Jiangsu were 22.67%, 16.67%, 17.33%, respectively; While it was 55.14% for Liaoning dominant lineage L12. In comparison to Jiangsu, the virulence of Liaoning strains was higher and the virulence diversity showed the opposite trend to the genetic diversity. Taken together, isolates from Jiangsu and Liaoning were similar in both pathogenicity and genetic structure but were significantly different in heterogeneity.

Soybean Fusarium wilt caused by Fusarium oxysporum is one of the most devastating soybean diseases worldwide. Understanding the population genetic characteristics of the pathogen and the resistance of soybean germplasm to soybean Fusarium wilt will benefit resistance breeding of soybean, reasonable distribution of resistant varieties and development of new disease management strategies. To clarify the genetic variation among F. oxysporum isolates, the genomic fingerprints of 55 isolates of F. oxysporum collected from different soybean-growing areas were analyzed by using 10 RAPD primers. The results showed that 75 bands were amplified and among them, 55 bands were polymorphic (73.3%). By using UPGMA, the 55 isolates were clustered into 9 groups when the threshold value of the similarity coefficient is 0.68, indicating that F. oxysporum isolates are diverse.We found that F. oxysporum isolates displayed pathogenicity differentiation on soybean lines and soybean lines also showed resistance differentiation to different F. oxysporum isolates. To make clear the resistance of soybean germplasm to soybean Fusarium wilt, 180 soybean lines from soybean-producing areas and breeding units were screened. The results showed that 5 lines (Wandou28, Zhonghuang13, Zhonghuang51, ZhongzuoX08076 and 5D034) were high resistant to soybean Fusarium wilt, accounting for 2.8% of the total materials. In addition, our findings revealed that the proportion of resistant germplasm in different soybean producing areas is different.

To understand the virulences of Puccinia triticina from Yunnan, Sichuan, Qinghai, Shanxi, Gansu and Henan in 2011-2012 crop season, 31 differential lines were used to identify the virulence phenotype and frequency of the 180 P. triticina collected from the six provinces. In total, 62 virulence phenotypes were detected mainly including SHJ(10%)、THT(8.9%)、PHK(6.1%)、SHN(5%)、PHT(4.4%)、SHD(4.4%)、PCH(3.9%)、THP(3.3%)and THK(3.3%). Virulence frequency to Lr2c, Lr10, Lr14a, Lr14b, Lr33 and Lr36 were all above 75% in the six populations indicating the loss of resistance of corresponding resistant genes. Virulence frequency to Lr9, Lr19, Lr24, Lr25, Lr28, Lr29, Lr38 and Lr42 were all below 30% in the six populations suggesting the effectiveness of these resistance genes. Virulence frequency to Lr2a, Lr3, Lr3bg, Lr20, Lr30 and Lr32 were variable in the six populations. Virulence diversity in Yunnan and Sichuan populations were the highest, followed by Henan, Gansu and Shanxi populations, Qinghai population was the lowest.

Host resistance and fungicides are two of the main approaches used to control plant diseases in conventional agriculture. The widespread use of host resistance and fungicides selects for pathogen individuals or populations that can overcome the host defense systems or that are resistant to the applied fungicides. One hundred and twenty nine isolates of Blumeria graminis f. sp. tritici were collected from 9 provinces/cities in 2012, and inoculated onto 31 differential wheat lines of powdery mildew to test the virulence. The sensitivity of the isolates to triadimefon was tested by seed treatment and detached leaf segment methods. The correlation between virulence diversity and triadimefon-resistance was carried out by SAS software. The results showed that median EC₅₀ of isolates to triadimefon was 109.97 mg/L,the coeffective of EC₅₀ was 107.2,the mean resistance factor (RF) was 52.62.The resistant frequency of all isolates to triadimefon was up to 99.22%. The mean resistant factors of B. graminis f. sp. tritici isolates from Beijing was higher compared to the other eight provinces. Virulence diversity of B. graminis f. sp. tritici isolates from Sichuan Province was highest with the index of virulence gene diversity 0.224 1. The virulence gene diversity of isolates from Zhejiang was lowest with the index 0.096 8. The association between triadimefon-sensitivity and virulence diversity of B. graminis f. sp. tritici isolates showed that there was no significant correlation among EC₅₀, variation coefficient of EC₅₀ and virulence diversity. However, there is a logarithmic (r=0.240 4, P=0.009 6) relationship between EC₅₀ and numbers of virulence genes of 129 B. graminis f. sp. tritici isolates. These results may provide a reference for reasonable utilization of wheat resistance varieties, as well as the use of triazole fungicides.

One thousand and three hundred ninety one wheat stripe rust samples were collected from 29 counties in Gansu, Sichuan, Shaanxi, and Tibet, China during spring of 2009-2010. Nine hundred and sixty one isolates of Puccinia striiformis f. sp. tritici were recovered from those samples. Population genetic diversity of the P. striiformis f. sp. tritici population containing 961 isolates was investigated with SSR technique. The results demonstrated that the genetic diversity of Tianshui, Pingliang and Longnan populations in Gansu, and Aba, Guangyuan populations in Sichuan was much higher than that in other regions. However, the genetic diversity of Yibin, Liangshan in Sichuan, and Linzhi in Tibet was lower than that in other regions. AMOVA of SSR was carried out using Arlequin software. Results showed that main genetic variation presented mainly within populations. Populations in inland (Gansu, Shaanxi, and Sichuan) had extensive gene exchange (Nm>4), and little gene exchange was found between Tibet and inland (Nm<1). The Structure and cluster analysis also indicated that there was almost no gene exchange between Tibet and inland populations. The frequent gene exchange was found between populations of Baoji in Shaanxi and Pingliang in Gansu, among populations of Hanzhong in Shaanxi, Longnan and Tianshui in Gansu, and Guangyuan in Sichuan. There was a certain gene exchange among populations of Yibin and Liangshan in Sichuan with Aba in Sichuan, Hanzhong in Shaanxi, and Longnan in Gansu. We preliminary argue that the population of P. striiformis f. sp. tritici in Tibet may be an independent from other populations under study.

In this study, two isolates of Cotton leaf curl Multan virus (CLCuMV), GD37 and GX01 were obtained from Hibiscus rosasinensis in Guangdong province and Gossypium hirsutum in Guangxi province, respectively. The complete nucleotide sequence identity between CLCuMV GD37 and CLCuMV GX01 is 99.4%, and the homology between their associated betasatellites(GD37β and GX01β)is 99.2%. The infectious clones GD37 and GX01 were constructed and their pathogenicities were then tested by agroinoculation. It was showed that CLCuMV GD37 could infect Nicotiana benthamiana, N. glutinosa, N. tabacum Samsun and N. tabacum producing downward leaf curl symptoms, but could not infect cotton, tomato and petunia. Co-inoculation of CLCuMV GX01 with its betasatellite GX01β, which were isolated from infected cotton, could induce severe downward leaf curl symptoms in N. benthamiana, but could not infect cotton. Southern blot analysis showed CLCuMV DNA could be detected in both GD37- and GD37 & GD37β-inoculated plants.

Stripe rust and powdery mildew are two major diseases of wheat in China. As typical airborne diseases, the airborne inocula bear a direct relationship to disease cycles including primary and secondary infections. The long distance pathogen dispersal leads to spread and regional development of diseases. Therefore, quantitative monitoring of airborne inocula and their dynamics become an important means for disease forecast and risk analysis of epidemics in the future. In this study, a set of duplex TaqMan Real-time PCR method was developed and used to quantify the DNA of Puccinia striiformis f. sp. tritici and Blumeria graminis f. sp. tritici so as to acquire quantitative information of inocula from air samples collected by the spore trap. The results showed that this method is accurate, specific and highly sensitive to quantify as low as 10 spores and applicable to monitor inocula dynamics.

In order to investigate the resistance of main wheat cultivars to wheat stripe rust in Tibet, and identify the existing Yr resistance genes in these plant varieties, 41 of wheat cultivars (lines) were evaluated for resis-tance level on adult plants under field conditions in Linzhi during 2011-2013, and the evaluation was conducted by using the known SSR markers linked with rust resistance genes Yr1, Yr5, Yr9, Yr10, Yr15, Yr18 and Yr26. The results showed that Yr1, Yr5, Yr9, Yr10, Yr15, Yr18 and Yr26 could be detected at a frequency of 4.4%, 4.9%, 17.1%, 0%, 19.5%, 14.6% and 36.6%, respectively. The resistance performance of wheat varieties in the field combined with the Yr gene detection results showed that two materials possibly carried Yr5, six materials possibly carried Yr9, three materials possibly carried Yr15, five materials possibly carried Yr18, two materials possibly carried Yr26, and eight materials including Zang 178 and 43351 displayed high or very high level of resistance, in which other unknown new resistance genes might be contained.

A new leaf spot disease of Highbush Blueberries (Vaccinium corymbosum L.) was found in Yunnan, China. Typical symptoms of the disease were circular to irregular, light brown-to-gray leaf spots with brownish red borders, initially 2 to 3 mm in diameter, enlarged and coalesced. All of isolates were isolated from leaf spot diseased samples of infected blueberry plants. Based on the the result of pathogenicity testing, it was proved that LANMEI036 isolate was the pathogen of Highbush Blueberries leaf spot. The LANMEI036 isolate was identified as Alternaria tenuissima based on morphological characters and sequence of rDNA internal transcribed spacer region (ITS1-5.8S-ITS2). Representative sequence of LANMEI036 isolate was deposited in GenBank (Accession No. KF791343). A. tenuissima was first reported as the pathogen of Highbush Blueberries leaf spot disease in China.

A bacteria strain 5877-A1 was isolated from dragon fruit (Hylocereus undatus) with typical soft rot symptom imported from Taiwan, China. Colonies of the isolate on nutrient agar medium were circular, oyster white, protuberant, smooth and mucous. The bacteria were Gram-negative and short rod-shaped in (0.44-0.88) μm×(0.83-2.82) μm. Inoculation of bacterial isolates into dragon fruit seedlings yielded characteristic soft rot symptom. Then it was identified as Enterobacter cloacea by Biolog Gen III and MALDI-TOF-MS test. Sequence analysis of 16S rRNA gene showed that it shared 99.9% sequence homology with E. asburiae, E. cancerogenus and E. hormaechei. Sequence and phylogenetic analysis of gyrB gene indicated that it was closely related to, but distinguishable from, E. asburiae and E. mori. The results showed it maybe an unreported species of the genus Enterobacter. This is the first report of Enterobacter sp. in dragon fruit from Taiwan.

To clarify the factors influencing differentiation of somatic compatibility in Rhizoctonia solani AG-1-IA causing rice sheath blight, the pathogen strain cx-2 was consecutively inoculated into different rice varieties and subcultured on PDA plates with different fungicides/pHs or at different temperatures. The comparison of somatic compatibility was made between the recovered/subcultured isolates and their original strain (cx-2) based on barrage zone formation on the face-to-face cultures. Meanwhile, amplified fragment length polymorphism (AFLP) was used to determine genetic difference between the recovered/subcultured isolates with alterations in somatic compatibility and their original strain (cx-2). The results showed that the isolates with alterations in somatic compatibility were recovered from 9 out of 30 rice varieties tested after four consecutive inoculations. The subcultured isolates with alterations in somatic compatibility were also detected after four consecutive transfers on the PDA plates with alkaline pH levels 10 and 11. However, no subcultured isolates with alterations in somatic compatibility were found even after ten consecutive transfers on the PDA plates containing different fungicides or at different temperatures. The isolates with alterations in somatic compatibility showed the same AFLP fingerprint patterns with their original strain (cx-2).

Leifsonia xyli subsp. xyli (Lxx) is the pathogen causing ratoon stunting disease of sugarcane and resulting in a considerable reduction in cane production. In this study, a TaqMan probe and a pair of primers were designed according to the Pat1 gene sequence of Lxx for detection of Lxx with real-time fluorescent PCR (RT-qPCR) technique. The results showed that only Lxx produced typical amplification curve and the minimum detection limit of RT-qPCR was 10² copies·μL^-1. Fourteen sugarcane varieties from National Regional Test were then used for Lxx detection assay by RT-qPCR and conventional PCR, and the detection level in these two methods were 86% and 43%, respectively, indicating the higher sensitivity of RT-qPCR in detection of Lxx. The study provides rapid, specific and sensitive technical support for diagnosis and monitoring of RSD, and seedling quarantine.

A serious bacterial leaf spot disease was commonly found on cultivated processing pepper in Bayinguoleng Mongol Autonomous Prefecture of Xinjiang. In order to identify the causal agent of the disease, bacterial strains were isolated from the diseased leaves, and the pathogenicity of the isolates was then confirmed by inoculation of the isolates on pepper seedling, potato soft rot test and the hypersensitive reaction on tobacco. Thirteen pathogenic isolates were obtained. Based on morphological, physiological and biochemical characteristics, pathogenicity test, 16S rDNA and rpoD gene phylogenetic analysis, the causal pathogen was identified as Pseudomonas syringae pv. syringae. By artificial inoculation, the isolates could also affect many other plants, such as tomato, eggplant, potato, cucumber, green bean, cabbage, carrot, celeries, etc.. This is the first report of P. syringae pv. syringae causing leaf spot disease on processing pepper in China.

800 T-DNA inserted mutants of high virulent Verticillium dahliae strain Vd080 producing microsclerotia were conducted pathogenicity tests. Among them, the virulence of 31 mutants exhibited significant reduction, and their biological characteristics was analyzed. The results of molecular identification showed that all the low virulent mutants were positive and 25 mutants had single T-DNA inserted. Compared with the wild type strainVd080, the mutant colonies showed diverse variation. Among them, 8 mutants were similar with wild type producing microsclerotia, there were also 3 yellow mycelia, 2 white mycelia and 12 intermediate strains. Furthermore, the growth rate, spore yield and crude toxin of most strains changed significantly, but the correlation among these physiological indicators was not significant. With the aid of TAIL-PCR technique and VdLs.17 genome database, the flanking sequences of the 25 single T-DNA inserted low virulent mutants were obtained, and the pathogenicity related genes were successfully cloned.

Rice blast, caused by Magnaporthe oryzae, is one of the most devastating fungal diseases of rice worldwide. Clarification of pathogenic mechanisms of the pathogen will help to find the potential target sites for new fungicide, and therefore the effective way for disease control. In this study, two methylene tetrahydrofolate reductases MoMet12 and MoMet13 in M. oryzae, orthologous to Saccharomyces cerevisiae Met12 and Met13 were identified, which has 691 and 632 amino acids, respectively, and shares 32% identity. Deletion of Mo-MET12 and MoMET13 resulted in decreased vegetative growth and aerial hyphae formation on CM media. ΔMomet13 was auxotrophic on MM and significantly decreased in growth rate and formation of aerial hyphae on OM and SDC media. The growth rate of ΔMomet12 was also dramatically decreased on MM、SDC and OM media. Further analysis revealed that ΔMomet13 lost the ability to produce conidia on both CM and SDC media, and ΔMomet12 significantly reduced conidiation on CM and was unable to produce conidia on SDC media. Infection assay showed that ΔMomet13 was decreased in virulence and had a defect in infectious hyphal growth. Exogenous methionine could restore the growth and conidiation defects of ΔMomet12 and ΔMomet13 mutants, and also partially rescue the virulence of ΔMomet13. These results indicated that MoMet12 and MoMet13 have crucial roles in vegetative growth and asexual development by modulating the biosynthesis of methionine, and MoMet13 is a key pathogenicity-related factor involved in infectious hyphal growth and virulence.

The optimal protein extraction method is the key for proteomics research by two-dimensional electrophoresis (2-DE). In this study, in order to establish a suitable method for extraction of total protein from the bark of apple branches, the extraction condition for the 2-DE was optimized. To elucidate the key proteins related to disease-resistance of apple branches induced by Botryosphaeria dothidea,total proteins were extracted from control and infected branches, and separated by two-dimensional electrophoresis. The differentially expressed proteins were then identified by MALDI-TOF-TOF/MS. In total, 25 differentially expressed proteins were detected by Image Master Software. After tryptic digestion, MALDI-TOF-TOF/MS analysis and database searching, 22 protein spots were finally identified. The predicted function of 22 proteins were related to photosynthesis, glucose/energy metabolism, defense responses, protein synthesis and other unknown functions. The pathogenesis-related proteins (APX, β-1,3-glucanase, Mal d1 and PR-1) involved in defense responses and differentially expressed in apple branches may play a key role in resistance to B. dothidea.

In this study, total RNA of hop leaves infected by Hop latent viroid(HLVd) was extracted by Magnetic Nanoparticles (MNP), LiCl precipitation, CTAB, TRIzol methods and RNeasy Plant Mini Kit. The comparison result indicated that the RNA extracted by MNP, LiCl and CTAB had high quality. And the MNP method had the advantages of short extraction time, simple operation, friendly environment and batch extraction. The MNP method was more suitable for rapid extraction of HLVd RNA. The RNA standard of HLVd was prepared by transcription in vitro and the standard curve was plotted. The specificity and sensitivity of the developed method for HLVd detection were determined. A rapid, sensitive and specific MNP-RT-qPCR assay for detection of HLVd was established.

The superoxide dismutases (SOD) play critical roles in the defense against oxidative stresses. Many studies have shown that improving SOD activity can increase the adaptation and tolerance to many environmental stresses for plants. Over-expression of SOD genes in plants can enhance their resistance to harmful environmental challenges. In this study, it was reported that transgenic rice constitutively expressing a Cu/Zn-SOD gene from Chaetomium thermophilum significantly improved their SOD activity and resistance to three major rice diseases, including bacterial blight, bacterial leaf streak and rice sheath blight. This single gene conferring resistance to various diseases could be important in the resistant breeding in plant.