In order to reveal the diversity characteristics of endophytes in different species and different organs,the correlation between endophyte community structure and host species and organ types was preliminarily clarified.The stems,leaves and leaf sheaths,which were respectively collected from the plants of the foxtail millet blast-susceptible varieties Shawan millet and Jigu 22 and the foxtail millet blast resistant varieties Xiaoqinggu and Shiliuzi,were used to carry out the endophytic diversity by high-throughput sequencing based on the 16S rDNA V3—V4 region.There were certain differences in endophyte species composition between susceptible and resistant varieties.In all tested samples,the dominant groups at the phylum level were Proteobacteria and Actinobacteriota.Bacteroidota,Chloroflexi,Myxococcota,Firmicutes followed.Alpha diversity analysis showed that the susceptible varieties(Shawan millet,Jigu 22)had higher abundance of endophyte in leaves.PCoA analysis revealed that the organ type had a greater impact on the endophyte community structure than the variety.Species composition analysis showed that the susceptible varieties Shawan millet and Jigu 22 contained endophytic flora that were significantly different from those of Xiaoqinggu and pomegranate(resistant to foxtail millet blast).The susceptible varieties(Shawan millet,Jigu 22)contained Entotheonellaeota phylum in leaves,while resistant varieties had Hydrogenedentes phylum in leaf sheaths.It clarified that the diversity and community structure of endophytes in different organs and millet varieties susceptible and resistant to foxtail millet blast were different,and organ types had a greater impact on the community structure of endophytes than varieties.

In order to improve the blast resistance of Shuijing 3,an excellent food-flavor rice variety,CRISPR/Cas9 gene editing technology combined with gene chip technology were used to pyramid the R gene Pigm and the non-R gene bsr-d1 into Shuijing 3.Firstly,Bsr-d1 was selected as the target gene to construct a recombinant expression vector using the CRISPR/Cas9 gene editing system,and transformed into the excellent food-flavor rice Shuijing 3 by Agrobacterium-mediated method.The homozygous bsr-d1 mutant lines without T-DNA elements,including five mutation types as T insertion,G insertion,GA deletion,CGCA deletion and CGCAGA deletion,were screened out.The japonica line Jinyu 1 containing a broad-spectrum blast resistance gene Pigm was used as the gene donor parent to cross with the homozygous bsr-d1 mutant lines without transgenic components.The Pigm gene was introduced into bsr-d1 mutant lines by cross,backcross and self-cross combing molecular breeding chip to simultaneously perform Pigm gene and background-assisted selection.The improved lines SJ3-G1,SJ3-G2,SJ3-G3,SJ3-G4,SJ3-G5,which were homozygous for the disease resistance genes(carrying both bsr-d1 and Pigm genes)and whose background recovery rates were all above 96%,were finally obtained.The improved strains of Shuijing 3 displayed enhanced leaf blast resistance compared with the wild type in inoculated identification test using Magnaporthe grisea strain GUY11.After inoculation with M.oryzae,the POD activities in the improved strains of Shuijing 3 were significantly lower than that of the wild-type control,while the H₂O₂ contents were significantly higher than that of the wild-type control.The improved Shuijing 3 lines with blast resistance carrying both bsr-d1 and Pigm genes are obtained by CRISPR/Cas9 gene editing technology combined with gene chip technology.

In order to excavate the mycovirus resources in Ustilaginoidea virens and deeply analyze the relationship between the genome organization and function of a novel mycovirus,it took a U.virens strain Uv321 with abnormal phenotype,isolated from Hainan Province,as the research object,and identified the species of the novel mycovirus in the strain Uv321 on the basis of the previous meta-transcriptome data,a series of studies have been carried out around the novel mycovirus.The results showed that a novel mycovirus was identified in strain Uv321,named Ustilaginoidea viruses botourmiavirus 7 (UvBV7).The genome of UvBV7 is positive single-stranded RNA(+ssRNA),with a total length of 2 406 nt and a GC-content of 53.78%,containing an open reading frame(ORF)encoding RNA-dependent RNA polymerase(RdRP),which encodes 643 amino acids with a molecular weight of about 72.727 ku.The prediction of the protein secondary structure of the viral terminal showed that the 5' and 3' terminal bases of UvBV7 were complementary and paired,forming a hairpin structure.The BlastP alignment showed that UvBV7 had the highest similarity with the virus Erysiphe necator associated ourmia-like virus 72,which belonged to the genus Botoulivirus in the family Botourmiaviridae,but only 44.52%.The multiple alignment results based on the RdRP sequences of UvBV7 and other similar viruses showed that there were 8 conserved domains in the RdRP amino acid sequences of UvBV7 and the members of the family Botourmiaviridae.The GDD motif was found in the Ⅵ conserved domain,which is the typical highly conserved core motif of viral RdRP proteins.The phylogenetic tree constructed based on the amino acid sequence of the viral RdRP also indicated that UvBV7 clustered with the members belonging to the genus Botoulivirus.Therefore,UvBV7 is a novel mycovirus belonging to the genus Botoulivirus in the family Botourmiaviridae.The results of dual cultures of different strains of U.virens showed that UvBV7 could be transmitted horizontally between vegetative compatibility strains,but the mycelial tip-ribavirin,heat-ribavirin and protoplast regeneration-ribavirin treatments were unable to eliminate the mycovirus UvBV7 in strain Uv321.In conclusion,this study not only enriched the diversity of mycoviruses in U.virens,but also provided potential biocontrol agents with hypovirulence for the biocontrol of rice false smut.

Bipolaris sorokiniana is one of the important pathogens of maize root rot.The purpose of the present work was to establish a rapid detection method for B.sorokiniana based on the loop-mediated isothermal amplification(LAMP).Firstly,a set of primers for LAMP assay was designed according to the partial sequence of Brn1 involved in the melanin biosynthetic pathway.Then,the optimal reaction temperature was screened for this primer set,the specificity and sensitivity of LAMP reaction were detected,and the LAMP detection was evaluated by using the maize root rot samples artificially inoculated with B.sorokiniana.The results showed that the primer set designed could amplify the target gene Brn1 at 61—68 ℃,with 66 ℃ was the optimal temperature.In the specific detection,the primer set could specifically detect B.sorokiniana from the genomic DNA of 10 main pathogenic fungi isolated from maize root rot plants.In the sensitivity detection,the minimum detection limit for plasmid DNA carrying Brn1 was 10 copies/μL,and amplification could be achieved in about 25 min at the minimum concentration.And,for the detection of maize root rot samples,B.sorokiniana can be detected in 1 pg/μL of maize root tissue DNA.These results indicated that the LAMP detection method for B.sorokiniana established in this study has robust specificity and high sensitivity.

In order to identify the pathogenic fungi which causing tomato bacterial wilt in Fengnan District of Hebei Province.This study proved the disease as Bipolaris sorokiniana by pathogen isolation,pathogenicity test,morphological observation,and rDNA-ITS gene sequence analyses was caused by Fusarium oxysporum f.sp.radicis-lycopersici(Forl).The result showed that the mortality and morbidity of stem based inoculation were higher than root soaking inoculation.So,the disease with stem based inoculation developed faster.The study provided theoretical basis for the breeding of disease resistance and the screening of the fungicides.

The adult plant resistance gene Lr12 exhibits excellent resistance in production systems.To fine map and develop reliable molecular markers for Lr12,a cross was made between the susceptible variety Thatcher and the resistant near-isogenic line RL6011 containing the Lr12 gene.The F₁ generation resulting from this cross was self-pollinated to generate F₂ individual plants and F_2∶3 families.Field evaluations were conducted using a mixture of five highly virulent leaf rust pathotypes (PHTT, THKS, THTT, PHTS, and PHKS) to inoculate F₂ individual plants and F_2∶3 families for adult plant resistance assessment and genetic analysis of resistance.Subsequently,genotyping was performed using a 16K liquid chip on 10 resistant and 10 susceptible individuals from the F₂ generation to identify SNP markers closely linked to Lr12.This enabled the determination of the chromosomal physical interval containing the resistance gene,the development of SSR molecular markers,and the construction of a genetic linkage map.The results indicate that the segregation ratio of resistance to leaf rust in 3 494 F₂ individuals derived from the RL6011(Lr12)/Thatcher cross was consistent with a 3∶1 ratio ( {\mathrm{\chi }}_{3:1}^2=0.14;P=0.71). In the assessment of 685 F_2∶3 families, the segregation ratio among resistant individuals, resistant heterozygous individuals, and susceptible individuals conformed to a 1∶2∶1 ratio ( {\mathrm{\chi }}_{1:2:1}^2=2.01;P=0.37), suggesting that Lr12 is a dominant gene and the population segregation follows Mendelian single-gene inheritance patterns. Genetic linkage map analysis localized the adult plant leaf rust resistance gene Lr12 between SSR molecular markers YK12817 and YK12928,within a genetic interval of 0.38 cM.This corresponds to a physical interval of 2.09 Mb within the physical range of 579.44 Mb to 581.53 Mb on chromosome 4BL of the Chinese Spring reference genome(IWGSC.Ref.V1.0).These findings provide a solid basis for predicting candidate genes.

In order to improve blast resistance of the maintainer line Ruanhua B,to carry rice blast resistance genes Pi46 and Pi2 high-quality Indica H281 as the donor parent,Ruanhua B as recurrent parent,using marker-assisted selection(MAS)technology combined with pedigree breeding method,polymerization of two foreign genes with improved maintenance line Ruanhua B resistance,Ruanhua B was carried out on the characteristics of stable strain identification of resistance to rice blast,rice quality analysis,etc.Two BC₁F₆ populations,two BC₂F₅ populations and two BC₃F₄ populations with two homozygous target genes were obtained by backcrossing,multi-generation self-crossing and molecular marker detection.Field naturally induced identification showed that the improved lines of different backcrossing generations were resistant to rice blast.The sterility of backcross generation to sterile lines ranged from 52.7% to 100.0%.Agronomic traits and rice quality analysis showed that the improved lines basically conserved the main agronomic characters and rice quality characteristics of Ruanhua B.The results of SNP gene chip analysis showed that the background response rate of BC₁F₆ was 74.42%—77.77%,that of BC₂F₅ was 86.42%—87.75%,and that of BC₃F₄ was 92.27%—92.59%.Multiple resistance genes can be effectively polymerized by continuous backcross,self-cross and marker-assisted selection techniques to obtain a new maintainer line resistant to rice blast,and achieve rapid molecular improvement of maintainer line Ruanhua B.

As an important component of plant cell wall,expansins have effects on loosening and increasing the flexibility of cell wall,and are thought to have function in many process of plant growth. To study potential function of expansin gene family in potato,we investigated expansin gene family with the whole genome database to analyse its structure,phylogenetic relationship and expression profiles. Potato genome contained 33 expansin genes which belonged to 4 subfamilies (EXPA (21),EXPB (5),EXLA (1) and EXLB (6)) located on 11 different chromosomes. Expansin proteins ranged from 194 aa to 488 aa in size and had conserved domains. All 33 Expansin proteins were predicted to localize in extracellular. Gene structure analysis revealed that seventy percent(23/33) expansin genes had 2-3 introns. Transcriptome analysis showed that the potato expansin genes expressed highly in root,stem,stolon,mature fruit and tuber.

In order to explore the role of RPM1 in sorghum disease resistance,a sorghum SbRPM1 gene was obtained from sorghum smut resistant variety SX44B by homologous cloning method.The bioinformatics analysis results showed that the total length of the cDNA of SbRPM1 gene was 2 802 bp,encoding 933 amino acids,and its protein had a theoretical molecular weight of 106.1 ku and an isoelectric point of 7.11,which was a hydrophilic protein.The SbRPM1 protein had no transmembrane structure,and its subcellular localization was in the cytoplasm.Conservative domain analysis showed that SbRPM1 protein contained RX-CC-like,NB-ARC and LRR domains,and belonged to CNL proteins in the NLRs family.Phylogenetic analysis showed that SbRPM1 protein was most closely related to the RPM1 protein of Miscanthus lutarioriparius.The expression pattern of SbRPM1 gene was detected by Real-time quantitative PCR,and the results showed that the expression of SbRPM1 gene was higher in leaves and inflorescence,followed by roots,and the lowest in stem.The expression of SbRPM1 gene was significantly up-regulated at 24—72 h in disease-resistant varieties after inoculation with Sporisorium reilianum pathogen,suggesting that this gene could be induced by S.reilianum and played an important role in sorghum disease resistance.In this study, the CDS sequence of the SbRPM1 gene was cloned for the first time in sorghum, and the structure, nature and expression of the gene were characterized.

There exists the compound infection of Tomato chlorosis virus (ToCV) and Tomato yellow leaf curl virus (TYLCV), and the incidence of the two diseases presents a tread of increase in recent years, which becomes a new threat to tomato farming. In order to study the interaction and variation of the two virus genes after single and mixed infection, the molecular identification and sequence analysis of the CP gene and the HSP gene of ToCV and the gene of TYLCV occurred in Tianjin were carried out. The results showed that, compared with the single infection samples, 6 base mutations of TYLCV were found in mixed infection samples, i.e. 73rd A→C, 92nd A→G, 347th C→T, 1 209th C→T, 1 618th A→G and 2 107th A→T, among which the 73rd and 92nd mutations were not in the coding region and the other four were located in the ORF box with 3 missense mutations and one samesense mutation(1 209th). There was also one samesense mutation in the CP gene of ToCV. There were 4 base mutations in HSP gene of ToCV, among which the 826th T→C and 1 166th G→A were samesense mutations, while the 1 395th A→G and 1 630th A→G were missense mutations. The accumulation amount of TYLCV and ToCV in tomato samples after single infection and mixed infection were analyzed by RT-qPCR. The results showed that the accumulations of TYLCV and ToCV had no significant difference between single infection and mixed infection. In the mixed infection samples, the copy of TYLCV was about 262-436 times that of ToCV.

To investigate the function of JsWRKY1, a constitutive expression vector of JsWRKY1 was constructed and transferred into Nicotiana tabacum L.cv Xanthi.There were no visible differences between the positive transgenic plants and WT.The expression levels of several defense-related genes MnSOD, Cu/ZnSOD, CN, NADPH oxidase, and PR1 resistance gene were up-regulated in the transgenic tobacco lines,and the SOD,APX and POD showed significantly higher activities in the transgenic lines than in wild type under normal conditions or after inoculation with C.gloeosporioides. The crude protein extract of transgenic tobacco lines inhibited the hyphal growth of the following four fungi, Botrosphaeria dothidea, Gibberella moniliformis, C.gloeosporioides and Fusarium oxysporum at different degrees.The antifungal activity in vitro plates demonstrated that the activities of SOD in the transgenic tobacco lines were significantly higher than those in WT.Moreover,the transgenic tobacco plants showed strong resistance after inoculation with C.gloeosporioides in the leaves.In conclusion,the JsWRKY1 is a positive transcription factor of J.sigiuata regulating the defense response to pathogens.

Abstract: Tetraploid wheat is the ancestor specie of common wheat and an important food crop.Aiming to provide new resistance sources for wheat variety breeding,the resistance tetraploid wheat germplasm was explored and their resistance genes were identified.TDI-1 is a cultivated emmer wheat that has been immune to powdery mildew in the field for many years.To determine the resistance genes carried by TDI-1,and provide a theoretical basis for genetic improvement of wheat resistance,a durum wheat TDU-1 that was susceptible to powdery mildew was used to hybridize with TDI-1,and their F₁ plants,F₂ population,and F_2:3 lines were obtained.Genetic analysis of resistance was conducted on parents TDI-1,TDU-1,and their hybrid offspring that were inoculated with powdery mildew isolate E09.Then,bulked segregant analysis method combined with molecular markers was used to map the resistance gene.The results showed that TDI-1 was susceptible to E09 during the seedling stage but immune during the adult stage.F₁ plants derived from the cross of TDI-1 and TDU-1 were immune to E09 during the adult stage.The resistance of adult F₂ individuals was separated,and the ratio of resistant and susceptible plants was 3:1($χ_{3:1}^{2}$=0.11,P=0.74);the ratio of the number of homozygous resistant,separated resistant,and homozygous susceptible F_2:3 lines was 1:2:1($χ_{1:2:1}^{2}$=0.47,P=0.79),indicating that the resistance to powdery mildew in the adult stage of TDI-1 was controlled by one dominant gene,temporarily named PmTDI-1.Subsequently,a set of molecular markers was used to amplify the parents and their F₂ population,and then four markers on chromosome 2A,including Xwmc407,NRM-2AS29,NRM-2AS45 and NRM-2AS84, confirmed to be linked to PmTDI-1. PmTDI-1 was between the flanking markers NRM-2AS45 and NRM-2AS84,with genetics distances of 1.8 cM and 4.6 cM,respectively.Therefore,the adult stage powdery mildew resistance gene PmTDI-1 was preliminarily localized on chromosome 2A.This study identified a novel dominant adult-plant-resistance powdery mildew gene PmTDI-1 from tetraploid wheat TDI-1.

To study the resistance mechanism of TaHis gene to Fusarium head blight(FHB)in wheat,the full-length coding sequence of TaHis was cloned,and the bait vector pGBKT7-TaHis was constructed,which was then used as bait for screening a yeast two-hybrid library of wheat ear induced by FHB.After obtaining the interacting proteins,yeast two-hybridization and bimolecular fluorescence complementation were further used to verify the interaction between these proteins,and RT-qPCR was used to analyze the expression pattern of TaHis interacting protein induced by FHB in resistant and susceptible cultivars respectively.The results showed that the bait vector pGBKT7-TaHis was successfully constructed,and 18 yeast monoclones were obtained on the four deficient selection medium(SD/-Leu/-Trp/-His/-Ade)after yeast two-hybrid library screening.Blast analysis showed that a total of 5 proteins were obtained,and the coding sequence of serine/arginine-rich mRNA splicing factor SR45a-like(TaSR)was identified in 6 colonies.We cloned the full-length coding region of TaSR gene from Bainong 4299 and constructed pGADT7-TaSR vector.The experiment of yeast two-hybrid showed that the yeast cells co-transformed with pGADT7-TaSR and pGBKT7-TaHis grew well and appeared blue on SD/-Leu/-Trp/-His/-Ade/ X-α-Gal/AbA,indicating that TaSR and TaHis directly interacted in yeast cells.The vectors of YC-TaHis and YN-TaSR were constructed,and the bimolecular fluorescence complementary experiments were performed.The results showed that strong fluorescence signals were generated in tobacco cells co-transferred with YC-TaHis and YN-TaSR,which further verified the interaction between TaSR and TaHis.RT-qPCR analysis of TaSR gene expression showed that TaSR expression was up-regulated in resistant cultivar Bainong 4299,while down-regulated in susceptible cultivar Bainong 607 upon FHB infection,indicating a positive correlation between TaSR expression level and FHB resistance in wheat.To sum up,the interaction between wheat TaSR and TaHis was proved,and TaSR expression level was positively correlated with FHB resistance in wheat.

To explore the effect of different leaf age on the yield and quality of flue-cured tobacco,the main cultivars K236 in Luoping tobacco-growing area of Yunnan were used as test materials to construct different flue-cured tobacco varieties with different leaf age. Photosynthetic potential in growth period and economic characters of post-baked tobacco leaf were analyzed. The results showed that with the increase of transplanting age,the survival rate of tobacco seedlings increased first and then decreased,while the field growth period increased; With the advance of fertility in the field of flue-cured tobacco,the photosynthetic potential (LAD) of the treatments decreased first and then increased,and the total LAD of the treatments was the highest in 5 leaves transplanted tobacco seedlings,which was 20.14% higher than that of 6 and 8 leaves respectively,14.82%. The mean leaf angle (MLIA) of the population increased first and then decreased with the increase of leaf age,while the extinction coefficient (K)was an increasing trend.The leaf tobacco leaves with 5 leaves were transplanted with appropriate chemical components and the quality was the best,followed by 4 leaves;6,7,8 leaves,because of its reducing sugar,starch,potassium content does not meet the requirements of high-quality tobacco chemical indicators,poor quality;With the increase of transplanting age,economic traits showed a trend of increasing first and then decreasing. Therefore,the optimum tobacco leaf transplanting age of tobacco leaves in Luoping tobacco-producing areas in Yunnan is 5-leaf-stage,which can shorten the period of nursery and shorten the time of cutting and reduce the time when the high yield value can be maintained. Such as smoke and the proportion of medium and high smoke,improve the grade structure and site structure.

Mitogen-activated protein kinase kinase (MAPKK or MKK) plays an important role in plant growth,development and stress responses.In order to identify MAPKK genes related to rust resistance in foxtail millet and provide candidate genes for the study of rust resistance mechanism and disease-resistant molecular breeding of foxtail millet,the members of MAPKK gene family (SiMKKs) in foxtail millet were identified and analyzed at the whole genome level by bioinformatics methods.Real-time PCR was used to detect the expression level of SiMKKs gene in different tissues,under the stress of rust fungus and exogenous hormone treatment.Excel,MEGA and DnaSP were used to analyze the variation sites and haplotypes of the SiMKKs gene related to rust resistance in 70 re-sequenced foxtail millet varieties,and the excellent rust-resistant haplotypes were identified based on phenotype analysis.The results showed that a total of 10 SiMKKs were identified in foxtail millet,which were distributed on 5 chromosomes.The number of exons ranged from 1 to 11,and the encoded protein contained 331-523 amino acids.The SiMKKs were divided into 4 groups.Groups A and B contained S/T-X₅-S/T motif,while SiMKKs in groups C and D did not have this motif.Conserved Motif 1-Motif 6 existed in all SiMKK proteins.The promoter region of each SiMKK gene contained 1 to 3 biotic stress-related cis-acting elements,such as defense and stress response,methyl jasmonate(MeJA) response,salicylic acid(SA) response and elicitor activation.Except SiMKK10-1 and SiMKK10-3,the other 8 SiMKK genes were expressed with different degrees in different tissues,and under rust infection,SA and MeJA treatments.The highest expression of SiMKK4,SiMKK5 and SiMKK10-2 were in roots at booting stage,and the highest expression of SiMKK6-1 and SiMKK6-2 were in stems at booting stage.The expression of SiMKK4 was up-regulated in the resistant response and down-regulated in the susceptible response within 24 h after inoculation,and its expression was related to disease resistance.The expression of SiMKK4 was up-regulated within 16 h and then down-regulatedafter SA and MeJA treatments,and showed continuous changes during SA treatment.In addition,the expression patterns of the remaining 7 SiMKK genes in SA and MeJA treatments were also consistent.The coding region of SiMKK4 gene contained 7 haplotypes and Hap_1 was the dominant haplotype,and no key variation sites related to disease resistance were found.In summary,the expression of SiMKK4 is identified to be associated with resistance to rust disease in foxtail millet,and SiMKK4 may participate in the early disease resistance response of foxtail millet through SA and MeJA signaling pathways.

To reveal the diversity characteristics of endophytic bacteria in different cultivars and organs,and clarify the correlation between endophytic bacteria community structure and host varieties,organ types and disease resistance and susceptible characteristics.Six different varieties of foxtail millet,Jigu 22,Honggu,Longgu No.11 and Xiaoqinggu,Shiliuzi and Nenxuan 16,which were resistant (susceptible) to Fusarium head blight,were selected as materials.The leaves,roots,stems,leaf sheaths and mature spikes of foxtail millet,were taken respectively.DNA was extracted for PCR amplification of 16S rDNA V3—V4 region,and Miseq library was constructed for high-throughput sequencing.Microbial diversity was analyzed by Major biological cloud platform.There were certain differences in endophyte species composition between susceptible and resistant varieties,the dominant populations of endophytes were Proteobacteria and Actinobacteriota,followed by Bacteroidota and Firmicutes,Myxococota and Chloroflexi were lower relative abundance followed by Gemmatimondota and Fusobacteriota.Alpha diversity analysis showed that the resistant cultivars had higher panicle community richness at leaf and maturity spikes and higher panicle diversity at leaf,root and maturity spikes.The susceptible varieties had higher richness of root and stem community and higher diversity of stem and leaf sheath;PCoA analysis showed that organ type had more effect on endophytic community structure than variety.Species composition analysis showed that the diversity of endophytic flora in foxtail millet was affected by different varieties and different parts,and the species of endophytic flora in different parts were quite different.The diversity of endophytic flora between susceptible cultivars Xiaoqinggu,Shiliuzi and Nenxuan 16 and resistant cultivars Jigu 22,Honggu and Longgu No.11 was quite different.The resistant cultivars had NB1-j in leaf sheath stage,and the ears had Acidobacteriota in mature stage.The study showed that the diversity and community structure of endophytic bacteria were affected by different organs and varieties of the foxtail millet,and the organ types had more influence on the community structure of endophytic bacteria than varieties.

Wheat powdery mildew is one of the main diseases threaten wheat production in China even all over the world. Screening and development disease-resistant varieties is a safe and effective way for prevention and control of wheat powdery mildew. The purpose of this study is to introduce powdery mildew resistance gene Pm30 into the wheat varieties Jizi 356 with advanced comprehensive agronomic characters and high yield developed by authors. One crosses,Jizi 356/Synthetics He-48 were made. Twelve lines with field resistance to powdery mildew and excellent agronomic characters were developed after six years of offspring screening. Then,seven lines were used for identifying resistance gene Pm30 using Xgwm159 SSR marker. Chinese spring and Pm30 were used as a contrast. The results showed that two new lines 14YF650 and 14YF675 could amplify the 430,460,500 bp polymorphic fragments. It indicated the two lines carrying Pm30 powdery mildew resistance gene derived from wild emmer. Those lines with big spikes,resistant to lodging and excellent agronomic characters could be used directly as parents for wheat powdery mildew resistance breeding.

To clone Pinellia pedatisecta agglutinin gene (PPA)from the leaves of Pinellia pedatisecta,analyzed on its biological information characteristics,and observed its subcellular localization.The open reading frame sequence of PPA gene was amplified by PCR method.The recombinant vector pCAMBIA1300-35S-PPA-eGFP was constructed and then transferred into Agrobacterium strain GV3101. Agrobacterium suspensions expressing PPA were injected at different concentrations into Nicotiana tabacum leaves and the subcellular location was observed by confocal laser scanning microscope.It showed that the open reading fragment sequence length of PPA gene was 777 bp,encoding 258 amino acids with GenBank accession number KF154981 and AGV40779,respectively.It contained two conservative B-lectin domains and three mannose binding sites.Sequence alignment demonstrated that the deduced amino acid sequence of PPA,which were 96%,91%,86% and 83% identical respectively,with the corresponding region of Arisaema heterophyllum, Pinellia cordata, Arisaema lobatum and Pinellia ternata.The subcellular location results indicated that the PPA-eGFP was located in the plasma membrane as large spots,but not found in nucleus.The results would provide the foundation for further study the structure and function of PPA gene,and elucidate anti-microbial mechanism of PPA.

Yuanjiang common wild rice(YP)is a germplasm material known as a living fossil in plants,which also has a large number of resistance(R)genes.Therefore,knowing the R genes in YP will help to apply different R genes to cultivated rice.Here,we identified the bacterial blight(BB)R genes in Yuanjiang common wild rice(YP),progeny of introgression lines(L214 and G252)and its susceptible parent,cultivated rice line 35(HX35).Meanwhile,the resistance of YP and its introgression lines to several Xanthomonas oryzae pv.oryzae (Xoo)strains was determined at the late tillering stage of rice.Under indoor control conditions,YP and its introgression lines showed resistance to 9 different Xoo strains(C1,C2,C3,C4,C5,C6,C7,C9 and PXO99^A),indicating that they had broad-spectrum resistance to BB.The results of bacterial blight resistance gene detection showed that YP contained homologous genes of Xa10,while HX35,L214 and G252 contained susceptible homologous genes of xa23.The sequence alignment results showed that the sequence of the effector binding element (EBE_AvrXa10) region of the disease resistance gene Xa10 was significantly different from that of the Xa10 promoter in YP. Similarly, the recessive susceptible gene xa23 was consistent with the effector binding element (EBE_AvrXa23) region of the xa23 promoter in HX35, L214 and G252. The qRT-PCR results showed that the immune responses in YP,HX35,L214 and G252 were activated after inoculation with strain PXO99^A,but Xa10 in YP and xa23 in HX35,L214 and G252 were not induced to be expressed.It is thus hypothesized that YP,L214 and G252 may contain new genes for resistance to bacterial blight.

This study aimed to screen the watermelon varieties and germplasms resistant to fusarium wilt, anthracnose and powdery mildew in Hebei Province, and analyze the related resistance genes, which could provide a reference for breeding disease-resistant varieties. The modified CTAB method was used to extract the DNA from watermelon bud, and the DNA concentration was determined by Ultramicro spectrophotometer. After the DNA was diluted to 2-10 ng/μL, they were detected by KASP. The molecular markers of resistance to fusarium wilt, anthracnose and powdery mildew of watermelon were developed by XU Yong's team. The resistant genes related to fusarium wilt, anthracnose and powdery mildew of watermelon were identified by high-throughput KASP markers. Totally 130 watermelon materials were tested, including varieties or advantaging combinations (Xingyan No.7, Meijia, Meisheng, Guifei, 17-11 and so on) that have been approved or will be approved in Hebei Province in recent years, and some excellent germplasms (Huazaolü,JB-1,JB-3,901xin and so on). 3Kang302 was used as the disease-resistant control and GBZG as the susceptible control. The result showed that 33 materials contained fusarium wilt resistance gene Fon-1, 19 contained anthracnose resistance gene AR1, 7 contained powdery mildew resistance gene PM1, 5 contained Fon-1 and AR1, 1 contained AR1 and PM1, and 1 contained all three resistance genes(Fon-1, AR1 and PM1). According to the result of KASP, the materials were clustered, and divided into 4 categories:12 materials resistant to powdery mildew without detection signal or with heterozygous resistance, 67 resistant to powdery mildew or susceptible to at least two diseases, 38 resistant to fusarium wilt or anthracnose, and 13 resistant to fusarium wilt or anthracnose or powdery mildew without detection signal or with heterozygous resistance.

Basic leucine zipper(bZIP)transcription factor protein is a kind of transcription factor with conservative structure and function in animals,plants and microorganisms.In order to clarify the function and mechanism of bZIP transcription factor in plant pathogenic fungi,and further determine its relationship with the growth,development and pathogenicity of the pathogen,the StbZIP9 gene was cloned from Setosphaeria turcica 01-23(GenBank No.XM _ 008032179.1).StbZIP9 is a member of the bZIP transcription factor family.The analysis of the gene structure and protein characteristics showed that the DNA sequence was 788 bp in length,with an open reading frame of 726 bp,encoding 241 amino acids.The encoded protein contained a highly conserved homologous domain BRLZ in fungi.The RNA-seq data of the gene during the growth and development of the pathogen and the process of infecting the host were analyzed.It was found that the expression level of StbZIP9 was 2 to 4 times higher than that in the appressorium and germ tube period compared with the mycelium period.After 24,72 h of infection of maize leaves,the gene expression increased from scratch and continued to increase,indicating that StbZIP9 was associated with appressorium development and germ tube formation and played an important role in the process of pathogen infecting host cells.Further,bioinformatics techniques were used to predict its binding conserved motifs and regulatory target genes.The binding motif was NNTWACGTNN,including the bZIP transcription factor recognition core sequence ACGT,and the downstream target genes of StbZIP9 were predicted according to the sequence.Combined with the expression pattern analysis using the RNA-seq data,four downstream target genes(protein IDs in the JGI database were :132893,163024,162798,40466)were obtained,and the functional annotation table was obtained.The functional annotation revealed its involvement in many biological processes, such as polymerization and transport of cell wall components, host infection, and spore dormancy. It will provide the basis for further elucidation of the molecular mechanism involved in the regulation of pathogen infection.

To investigate the genetic mechanism behind Annong 1687's ability to resist stripe rust,expedite the dissemination of Annong 1687 wheat variety,offer guidance for enhancing the genetics of novel wheat varieties,and mitigate the damage inflicted by wheat stripe rust on Chinese wheat production.This study employed Annong 1687(Annong 1687 is a semi-winter wheat type with resistance to the less significant physiological species CYR32.It was developed through the crossing of Annong 1106 and Xinong 822)with its sister lines,and parents.The wheat 55K SNP microarray was used to scan the entire genome of Annong 1687 as well as parents and sister lines.Concurrently,Annong 1687 and sister lines were inoculated and characterized employing the physiological race CYR32.The resistance to stripe rust grades was noted at the adult stage of the plant,and the resulting combined inoculation and field phenotypes were evaluated for stripe rust resistance of the wheat lines.The study revealed that Annong 1687 and five sister lines (lines 24,26,28,30 and 140) exhibited moderate resistance to stripe rust,while two sister lines (lines 89 and 105) displayed moderate susceptibility to this disease.Based on genomic differential data comparing Annong 1687 to its sister strains,there was evidence of enriched differential SNP loci in the 31—37 Mb segment of chromosome 2A's short arm,indicating possible presence of a gene or genes responsible for the result.To eliminate any potential interference from other stripe rust resistance genes,we verified the known stripe rust resistance genes present on the parental and chromosome 2A.Our findings indicated the possibility of a new stripe rust resistance gene in the 31—37 Mb interval of the short arm of chromosome 2A in Annong 1687.Experimental and bioinformatic analyses demonstrated that the TraesCS2A01G070700 gene exhibited disparity in the NBS structural domain of resistant and susceptible lines within this interval.Additionally,susceptible lines possessed three missense mutations within the NBS structural domain.It was hypothesised that TraesCS2A01G070700 represented a candidate gene for resistance to stripe rust in Annong 1687.