Peach shoot blight caused by Diaporthe amygdali (anamorph Phomosis amygdali) is a significant fungal disease in major peach-producing regions of southern China, which has severely hindered the development of peach industry and resulted in substantial economic losses for peach farmers. This paper presents a comprehensive review on its historical occurrence, distribution, damage, as well as biological characteristics of the causing pathogen, pathogen detection, disease cycle, and integrated prevention and control strategies for the disease. Furthermore, potential issues are analyzed and directions for future research are proposed. The review provides a reference for further studies on peach shoot blight.

Tomato brown rugose fruit virus (ToBRFV) has been spreading rapidly in tomato-producing areas around the world in recent years, causing severe economic losses. Symptoms of suspected ToBRFV infection appeared on tomatoes in Jianshui, Yunnan Province, and caused harm to the surrounding tomato production areas. In this study, the tomato samples suspected of being infected with ToBRFV in the Yunnan Jianshui field were identified by electron microscopy and RT-PCR. RT-PCR amplified the whole genome sequence of the virus, and the phylogenetic tree was constructed to analyze the evolutionary relationship of the viruses. The results showed that the rod-shaped virions, about 18 nm × 300 nm, with the typical structural characteristics of Tobamovirus, were found in the diseased tomato fruits.The target segment of 591 bp was amplified by RT-PCR using ToBRFV-specific detection primers.The Blast result in NCBI showed that this segment shared the highest identity (more than 99.00%) with the ToBRFV. We named this ToBRFV isolate as ToBRFV-2022-JS (GenBank accession number:OR593752). Sequencing result revealed that the complete sequence of ToBRFV-2022-JS was 6 386 nt, with four ORFs encoding the 126 kDa and 183 kDa replicates, the 30 kDa movement protein (MP), and the 17.5 kDa capsid protein (CP), respectively. Phylogenetic tree analysis showed that this isolate was the closest relative to ToBRFV Yinchuan isolate (GenBank accession number: OR500698.1), with 99.73% nucleotide sequence identity. The above results indicated that tomato fruits in Jianshui, Yunnan were infected with ToBRFV. The results provide a basis for the monitoring, prevention, and control of ToBRFV in tomato production areas in Yunnan.

The effects of synergism between sweet potato chlorotic stunt virus (SPCSV) and sweet potato feathery mottle virus (SPFMV) on photosynthesis, submicroscopic leaf epidermis structure, and chloroplast ultrastructure of sweet potato were studied using sweet potato plants infected with either SPCSV, SPFMV, or a combination of the two. The results showed that the net photosynthetic rate, stomatal conductance, transpiration rate, CO₂ utilization efficiency, and chlorophyll content of sweet potato plants were significantly decreased, and the activities of antioxidant enzymes and malondialdehyde content were increased due to the co-infection of SPCSV and SPFMV. Scanning electron microscopy showed that the co-infection of SPCSV and SPFMV could induce stomatal closure, leaf surface depression, and guard cell shrinkage, whereas no significant changes occurred in the single-infected plants,compared to the healthy plants. By using a transmission electron microscope, we found that the co-infection with SPCSV and SPFMV resulted in a reduction in the number and severe distortion of chloroplasts and the presence of large numbers of cylindrical inclusions in the cytoplasm of sweet potato plants. In the single-infected sweet potato plants, the number of chloroplasts remained unchanged, while some alternations on the ultrastructure were found, including increasedswollen starch granules and some loosely arranged grana and stroma lamellae.

Botrytis cinerea, a phytopathogenic fungi with a wide host range, can cause gray mold disease in many important crops. During infection of plant, B. cinerea secretes numerous cell death-inducing proteins (CDIPs) to induce host cell death, which as a result promotes its infection. In this study, we analyzed the secreted proteome during the infection stage of B. cinerea and identified a secreted protein BcXYG3, which contains GH12 and fCBD domains. Transiently expression of BcXYG3 rather than BcXYG3^Δsp (BcXYG3 without a signal peptide) in Nicotiana benthamiana leaves could induce cell death, suggesting that BcXYG3 possibly functions in plant cell apoplastic space. The expression of BcXYG3 was upregulated during the infection stage of B. cinerea. However, deletion or over-expression of BcXYG3 did not significantly affect the pathogenicity, growth rate, conidial production, and some stress tolerance of the pathogen. In addition, infiltration of purified BcXYG3 into N. benthamiana leaves could trigger plant resistance and the expression of defense-related genes. In conclusion, the secreted protein BcXYG3 of B. cinerea can trigger cell necrosis and resistance in plant, playing significant roles in the interaction between B. cinerea and host plant. The result is helpful for clarifying the mechanism underlying B. cinerea-plant interaction and provides theoretical basis and genetic resource for breeding of resistant crop varieties against gray mold disease.

Peach brown rot is one of the major diseases of peach, which causes significant losses to growers when it occurs in large scale. Currently, research on brown rot disease mainly focuses on the isolation and identification of the pathogen, fungicides resistance, and control measures. While the study on the pathogenic mechanism of the causing agent Monilinia fructicola, is relatively rare. This study is based on the previously obtained genome of M. fructicola and its early-stage transcriptome from infected fruit. Through PHI annotation analysis, it was found that the MfATG1 gene may play an important role in the infection process of M. fructicola. By using gene knockout technology, the knockdown positive transformants of MfATG1 gene were obtained, and their growth and development, virulence, and other stress-resistant phenotypes were compared with the wild-type strain to analyze the biological functions of the gene. The research results showed that the knockdown of MfATG1 gene affected the mycelial morphology and autophagy process, reduced mycelial growth rate and virulence of M. fructicola, but does not affect spore germination, indicating that MfATG1 gene is involved in the regulation of mycelial growth, virulence, and autophagy process in M. fructicola. Under NaCl stress conditions, the knockdown transformants increased the sensitivity to NaCl, indicating that the MfATG1 gene is involved in the response to salt stress. Under H₂O₂, SDS, and Congo red stress conditions, the knockdown transformants reduced the sensitivity to them, indicating that MfATG1 gene participates in the control of cell wall integrity and the oxidative stress response in M. fructicola.

The nuclear transcription factor Y (NF-Y) plays an important role in plant growth and development and in the response to abiotic stresses, but the mechanisms by which they are involved in insect and microbial interactions are less well understood. The purpose of this study was to identify the gene members of the NF-Y family of sorghum by bioinformatics, analyze their sequence characteristics, determine the spatio-temporal differences in gene expression in sorghum tissues, respond to Melanaphis sacchari and Sporisorium reilianum infection and DNA variation analysis. In the sorghum genome screened to 9 NF-YA subfamilies, 15 NF-YB subfamilies and 12 NF-YC subfamilies, is unevenly distributed on 10 chromosomes, and the gene structure of members in the same subfamily is similar, and most of the closely related members of the SbNF-Y family have similar exon-intron structures and conservative motifs. The encoded NF-Y proteins are all hydrophilic proteins, and the secondary structure is dominated by α helix and random curl; The results of protein domain analysis showed that the CBFB_NFYA was a conserved domain of the NF-YA subfamily, CBFD_NFYB_HMF a conserved domain of the NF-YB and NF-YC subfamilies. Analysis of gene promoter cis-acting elements showed that the promoter region of the NF-Y family of sorghum contained a large number of core elements, such as photoresponsive elements and a variety of elements that responded to the environment and hormones. Phylogenetic tree analysis showed that the NF-Y family was relatively conserved in the evolutionary process, and there was no obvious differentiation between monocotyledons and dicotyledons, and the relationship between sorghum NF-Y and maize was the closest; Gene expression analysis showed that there were significant differences in the expression of members of the NF-Y family of sorghum in different sorghum varieties and tissues. Expression of SbNF-YB3.2g and SbNF-YB11.7g were significantly enhanced after cane aphid infestation. Expression of SbNF-YB10.2g and SbNF-YB11.7g were significantly enhanced by head smut fungi infection. SNP/INDEL DNA variations were identified for future development of breeding selection. This study preliminarily analyzed the gene structure and expression of the NF-Y family of sorghum, aiming to provide a theoretical basis for the breeding of sorghum aphid resistance and head smut resistance.

Melampsora larici-populina can cause poplar leaf rust which is a widely distributed and severely harmful poplar foliar disease. Simple sequence repeats (SSRs) are widely distributed in genomes and serve not only as genetic markers for population genetics analysis but also play an important role in the evolution of genes and genomes. In this study, a total of 10 628 SSR loci were identified at the whole-genome level of M. larici-populina, the proportion of mono-nucleotide repeat is the highest, accounting for 53.2%, and the A/T repeat is the most abundant base type. The frequency and distribution types of the SSR loci have their own characteristics in different regions of the M. larici-populina genome. The highest SSR frequency was observed in the 3' untranslated region (3'UTR), one SSR locus is distributed per 2.16 kb, and the tri-nucleotide repeat is the predominant type in coding regions. The enrichment analyses revealed a higher likelihood of SSRs in genes related to signal transduction and cell cycle. Based on the genome-wide InDel information of M. larici-populina, 3 126 potential polymorphic SSR loci were predicted, then 10 randomly selected loci were used to design primers for polymorphism verification, and finally, seven SSR markers with high polymorphic information content and three SSR markers with moderate polymorphic information content were found. The results help us to understand the SSR characteristics of M. larici-populina at the whole genome level, and provide novel and efficient SSR markers for subsequent population genetic studies of this pathogen.

Stripe rust and powdery mildew are two important diseases on wheat worldwide, breeding and gro-wing resistant cultivars is the most economical and effective method to control these diseases. To determine the level of resistance and distribution of resistance genes in commercial wheat cultivars and regional trial lines to stripe rust and powdery mildew in stripe rust and powdery mildew main epidemic areas Shaanxi, Gansu, Sichuan, and Qinghai in China, 194 wheat cultivars (lines) were inoculated with the Chinese prevalent Puccinia striiformis f.sp. tritici (Pst) and Blumeria graminis f. sp. tritici (Bgt) races in both seedling and adult-plant stages, respectively. The results showed that 81 (41.80%) and 33 (17.00%) wheat entries were resistant to the mixture of Pst and Bgt races at the seedling stage, respectively; and 137 (70.60%) and 111 (57.20%) entries showed resistance to Pst and Bgt at the adult-plant stage, respectively. Also, the stripe rust and powdery mildew resistance genes were detected using Genotyping by Targeted Sequencing (GBTS) technology. The results indicated that 16, 9, 68, 62, 31, 88, 3, 5, 16, 9 and 1 entries were postulated to carry the Yr17, Yr26, Yr29, Yr30, Yr75, Yr78, Yr80, Yr82, YrAK58, YrSP and Pm21 genes, respectively; and 85, 30, 145, 47, 8, 78, and 89 entries may carry QYrsn.nwafu-1BL, QYrsn.nwafu-2AS, QYrqin.nwafu-2AL, QYrhm.nwafu-2BC, QYrsn.nwafu-3DL, QYr.nwafu-4BL, QYrsn.nwafu-6BS stripe rust QTL loci, respectively. No entries were detected to carry Yr18, Pm2a, Pm5e, and PmV resistance genes. This study provides a theoretical basis for breeding wheat with disease-resistant genes and distributing them rationally.

Pepper anthracnose, one of the main diseases in pepper production, seriously affects yield and fruit quality of pepper plants. To clarify the sensitivity of Colletotrichum scovillei to some commonly used fungicides in controlling pepper anthracnose in Shanxi Province, and also the resistance risk of C. scovillei to tebuconazole, the sensitivity of 93 C. scovillei strains from different pepper-producing areas in Shanxi Province to the 4 fungicides was determined by using the mycelial growth rate method. Ten tebuconazole-resistant C. scovillei isolates were generated by fungicide adaptation, and the fitness of these resistant isolates was investigated. The results showed that the average EC₅₀ values of tebuconazole, difenoconazole and prochloraz against C. scovillei were 0.364 1 ± 0.019 2, 3.126 7 ± 1.221 2 and 0.817 1 ± 0.328 3 μg·mL^-1, respectively; the sensitivity frequency of the C. scovillei isolates to these 3 fungicides was all distributed as a continuous unimodal curve (an approximately normal distribution), and no population with reduced sensitivity was observed. The average EC₅₀ value of pyraclostrobin to C. scovillei was 0.123 6 ± 0.190 8 μg·mL^-1, with a 2 930.98-fold difference between the maximum and minimum values; the sensitivity frequency of the C. scovillei isolates to pyraclostrobin was distributed as a left-skewed curve, and population with reduced sensitivity appeared. Among the 10 tebuconazole-resistant C. scovillei isolates, including 6 lowly resistant and 4 moderately resistant isolates, the resistance of 6 isolates could be stably inherited. Compared with the tebuconazole-susceptible parent C. scovillei strains, the mycelial growth rate, sporulation and pathogenicity of the tebuconazole-resistant strains were decreased. Further investigation showed that cross-resistance existed between tebuconazole and difenoconazole in C. scovillei, while no cross-resistance existed between tebuconazole and prochloraz or pyraclostrobin. The results provide a basis for the prevention and control of pepper anthracnose in Shanxi Province.

To clarify the population composition of pathogens causing citrus brown spot in China and their sensitivity to succinate dehydrogenase inhibitors (SDHIs), 135 diseased samples from 7 major citrus-producing regions were collected and pathogen isolation and identification was conducted in this study. Meanwhile, fungicide sensitivity test of the dominant pathogen species was carried out. Among 155 Alternaria strains isolated, the number of A. gaisen has surpassed that of A. alternata, becoming the new dominant pathogenic population. The sensitivity of 100 A. gaisen strains to boscalid and fluopyram was determined using the mycelial growth rate method. The results showed that the EC₅₀ values for boscalid ranged from 0.4129 to 4.7137 mg·L^-1, with an average value of 1.9257 mg·L^-1; for fluopyram, the EC₅₀ values ranged from 0.1272 to 3.3648 mg·L^-1, with an average value of 1.1149 mg·L^-1. The sensitivity curves of the A. gaisen population to these two fungicides were continuous and unimodal, conforming to a normal distribution according to the Kolmogorov-Smirnov test (K-S test), and no strains showed resistance. Therefore, 1.9257 mg·L^-1 and 1.1149 mg·L^-1 were established as the sensitivity baselines for A. gaisen to boscalid and fluopyram, respectively. Moreover, there were no significant differences (P＞0.05) in sensitivity of A. gaisen from different regions to these two fungicides, with all strains showing generally higher sensitivity to fluopyram than to boscalid. This study provides important data support and technical basis for the utilization of boscalid and fluopyram in the control of citrus brown spot disease.

Wheat Fusarium crown rot (FCR) is a soil-borne disease caused by F. pseudograminearum. The pathogen can produce various mycotoxins and cause wheat plants with white head, which poses a serious threat to wheat yield and food security. In order to clarify the inhibitory effects of tebuconazole on different growth stages of F. pseudograminearum and the efficacy of tebuconazole in controlling FCR, the effects of tebuconazole on mycelial growth, conidial germination, germ tube elongation and sporulation of F. pseudograminearum were studied, and the field control efficacy test was carried out. The results showed that the EC₅₀ value of tebuconazole on mycelial growth of F. pseudograminearum was (0.056 0±0.032 1) μg·mL^-1, and the EC₅₀ value on conidial germination was > 50 μg·mL^-1. By comparing the activity of tebuconazole on three F. pseudograminearum strains at mycelial growth, sporulation, conidial germination and germ tube elongation stagey, it was found that the EC₅₀ value of conidial germination was the highest (> 8 μg·mL^-1) while EC₅₀ values of germ tube elongation and sporulation were the lowest (< 0.01 μg·mL^-1). The teratogenic effect was increased as the concentration of tebuconazole higher. The results of field control efficacy of 430 g·L^-1 tebuconazole FS on FCR at different growth stages of wheat showed that the relative control effects at jointing stage of wheat were 67.38 % and 71.85 % for Yichuan experimental field and Xin 'an experimental field, respectively. At the late filling stage, the relative control effect for Yichuan experimental field was 37.19 %, and for Xin 'an experimental field it was 36.89 %. At the milky stage, the white head ratio of wheat in Yichuan experimental field was 6.30 %, and that was 7.21 % in Xin'an experimental field. There was no significant difference in the control efficacy between 430 g·L^-1 tebuconazole FS and the control fungicide 25 g·L^-1 fludioxonil FS. There was also no significant change in 1000-grain weight after treatment with the two fungicides compared with the control, indicating that wheat seeds dressed with tebuconazole FS did not affect the quality of wheat grains in the coming year. The results showed that tebuconazole had a strong inhibitory efficacy on mycelial growth, sporulation and germ tube elongation of F. pseudograminearum, and field experiments showed that tebuconazole seed dressing could effectively control FCR.

To determine the biocontrol effect of volatile organic compounds (VOCs) produced by Bacillus velezensis C11 strain against Botrytis cinerea, the pathogen causing tomato gray mold, a double petri dish assay was performed to evaluate the effect of B. velezensis C11 VOCs on mycelial growth, micromorphology, sporulation and cell membrane permeability of B. cinerea, on the occurrence and severity of gray tomato through detached leaf inoculation test, and on the activity of defense-related enzymes including POD and CAT in tomato leaves. The results showed that VOCs produced by B. velezensis C11 significantly inhibited mycelial growth of B. cinerea, with an inhibition rate of 78.35%; led to significant decrease in sporulation, cell membrane damage, and change in mycelial micromorphology; had a control effect of 76.9% on tomato gray mold. SPME-GC-MS assay was further employed to analyze the active components of B. velezensis C11 VOCs, and 27 substances were identified, 8 of which accounted for a relatively high proportion (5.43%). All these 8 compounds showed significantly inhibitory effect against B. cinerea at a concentration of 0.5 nmol·mL^-1. In conclusion, B. velezensis C11 strain can inhibit B. cinerea by producing VOCs. This study provides a theoretical basis for further investigation of the antagonistic mechanism of B. velezensis C11 strain.

Hulless barley (Hordeum vulgare L. var. nudum), known as Qingke, is the only cereal staple food crop widely planted on the Tibet Plateau (TP). Ear rot is an important new disease of Qingke occurring throughout the TP in recent years. The causal agent Dactylobotrys graminicola is a critical source of food for grass mite (Siteroptes spp.), and grass mite in turn serves as a vector for spreading the fungus. As a result, mutualistic symbiosis relationship is established between them. However, no effective method is available for controlling the disease. It is important to investigate the diversity of symbiotic bacteria of grass mite and find out the predominant bacteria, which is helpful for exploring regulation mechanisms in maintaining the stability of grass mite-D. graminicola system. This study sheds light on the development of new green control method of Qingke ear rot. In this study, adult grass mites were collected from diseased Qingke ears and the surface soil of Qingke-planting fields where ear rot occurred. The symbiotic bacteria (both on the surface and inside of mite body) or those (only inside of mite body) were isolated from living mites or their ground tissues, respectively. Bacterial isolates were sequenced with specific primers of 16S rDNA and the resulting data were statistically analyzed. For the grass mites collected from surface soil, symbiotic bacteria of 23 genera were detected from both surface and inside of mite body, and 16 genera were found only inside of mite body, of which 9 were confirmed to distribute both on surface and inside of mite body; Microbacterium, Rhodococcus and Streptomyces of the phylum Actinomycetota were the predominant bacteria among the symbiotic bacteria (both on the surface and inside of mite body), followed by Pseudomonas and Stenotrophomonas; The percentages of Microbacterium (52.1%) and Pseudomonas (22.1%) inside of mite body were significantly higher than those from both surface and inside of mite body (33.7% and 6.8%), and Streptomyces was merely detected on mite body surface. For the grass mites collected from diseased Qingke eras, symbiotic bacteria from both surface and inside of mite body were identified as 16 genera , and those inside of mite body were classified into 18 genera, of which 14 were detected from both surface and inside of mite body; Three genera Stenotrophomonas, Pseudomonas and Alcaligenes of the phylum Pseudomonadota were the predominant symbiotic bacteria of grass mites on diseased ears, with a higher percentage than that of mites in surface soil, followed by Microbacterium and Rhodococcu of phylum Actinomycetota, with remarkably lower percentages than that of soil mites. The number of Actinomycetota isolates from grass mites in epidemic field soil was 2.1 to 2.8 times of the one of Pseudomonadota isolates, whereas the number of Pseudomonadota isolates from grass mites on diseased ears was 1.9 to 2.4 times of the one of Actinomycetota isolates. So, significant differences existed in symbiotic bacterial community detected on grass mites from surface soil and from diseased Qingke ears. Among all the detected bacteria, Microbacterium, Rhodococcus, Streptomyce, Pseudomonas and Stenotrophomonas were the most dominant bacteria, which may play critical roles in facilitation of infection of younger Qingke ears by D. graminicola and fungal reproduction, providing indispensable nutrient source for grass mites.

In order to study the control effect of photosynthetic bacteria isolated from kiwi rhizosphere soil samples of Yuxi City, Yunnan province on tobacco mosaic virus (TMV) , we measured the yield of the secondary metabolite 5-aminolevulinic acid (5-ALA) from the isolated photosynthetic bacteria, and screened out a strain YN-1 with the highest yield of 5-ALA. Subsequently, the control effect of YN-1 and its secondary metabolite 5-ALA on TMV was tested, and the mechanism was investigated. The strain was identified as Rhodopseudomonas palustris by morphological identification, gram staining, physiological and biochemical tests of carbon and nitrogen sources and 16S rDNA sequence analysis. The 5-ALA yield of this strain is as high as 4.37 mol·L^-1. The incidence of TMV was decreased by spraying YN-1 fermentation liquid and secondary metabolite 5-ALA respectively. The results showed that the incidence of TMV on plants treated with YN-1fermentation liquid was 69.88% and 24.24% lower than those with water and 5% amino oligosaccharide 300 times treatments, respectively. The incidence of TMV on plants treated with 40 mg/L 5-ALA decreased by 74.70% and 36.37% compared with those with water and 5% amino oligosaccharide treatments, respectively. Through the analysis of plant resistance genes, it was found that the resistance genes in SA pathway were significantly upregulated compared with the control. The results showed that YN-1 fermentation liquid and 40 mg·L^-1 5-ALA could effectively reduce the infection degree of TMV.

In order to clarify the occurrence of root rot disease in Yunnan apple producing areas, the types of pathogens and the existence of new pathogens, this study aims to investigate the presence of root rot pathogens in Yunnan apple orchards and identify any potential new pathogens. Disease samples were collected from apple producing areas in Yunnan. The pathogens were obtained by tissue isolation, and the pathogenicity was verified by Koch's rule. The identification of pathogen was preliminarily determined by combining morphology. Furthermore, molecular biology identification was carried out based on the method of internal transcribed spacer and large subunit multi-locus gene joint construction. Phytopythium was isolated from Jian chuan County, Dali City, and Ning lang County, Lijiang City. It was confirmed through pathogenicity determination so that it could cause apple root rot. Through morphology combined with molecular biology characters. It was identified as Phytopythium litorale and P. cucurbitacearum. This study represents the first report of apple root rot caused by the pathogens P. litorale and P. cucurbitacearum in China. The results provide a theoretical basis for the development of monitoring disease occurrence and comprehensive control technology.

Broomcorn millet (Panicum miliaceum L.), one of the world's oldest cultivated crops, has excellent water use efficiency and is mainly used for dryland farming. In 2021, a new foliar disease of broomcorn millet occurred in Longdong of Gansu Province, China. The diseased leaves showed variably-sized, nearly circular brown blotches with dark brown margins, and the adaxial surfaces of blotches had small black dots. Based on morphological characteristics and multi-locus phylogenetic analysis involving ITS, LSU and RPB2, and the pathogenicity test, the pathogen of broomcorn millet causing leaf spot was identified as Boeremia exigua. To our knowledge, this is the first report of B. exigua causing leaf spot on broomcorn millet in China.

Prunus tomentosa is a deciduous shrub native to China that has been widely cultivated for an extended period throughout Eastern Asia for its flowers and fruit. Between 2021 and 2023, fruit anthracnose was observed in the Beijing and Shandong provinces of China. Symptoms initially presented as yellow, caviar-like patches on the fruit surface, which gradually enlarged into sunken brown spots, ultimately leading to fruit rot. To identify the causal agent, fungal isolate MYT24 as a representative strain was obtained from symptomatic fruits and identified as Colletotrichum fioriniae based on morphological characteristics and molecular phylogenetic analysis. The C. fioriniae was re-isolated from the disease fruit and the morphology was consistent with the original, fulfilling Koch’s postulates, which was confirmed as the causal agent of this disease. To our knowledge, this is the first report of C. fioriniae causing fruit anthracnose in P. tomentosa in China.

Hydrangea macrophylla, as one of the three major garden plants worldwide, has high ornamental and economic value. In March 2023, severe leaf spots were observed on H. macrophylla in the greenhouse in Xiqing District, Tianjin. Tissue separation was carried on to gain a pure strain that caused brown leaf spot on H. macrophylla, and its pathogenicity was confirmed based on Koch's postulates. According to morphological features and phylogenetic analyses of rDNA-ITS, GAPDH, and Alt a1 gene, the pathogen was identified as Alternaria alternata. This is the first report of A. alternata causing leaf spot on H. macrophylla in China, which is going to pave the road for disease diagnosis and effective control strategies.

Cigar is an important economic crop in Yunnan province. Recently, the wilt disease occurred seriously on cigar in Lincang city, Yunnan province, China. To explore the main pathogenic fungi of cigar wilt, pure strains were obtained from the disease samples by using the tissue isolation method. Twenty-one representative isolates were subsequently obtained and exhibited identical morphological characteristics. All isolates produced large conidia with sickle shap, small conidia with kidney shape, chlamydospores with round or oval shape; A representative isolate (YX39-1) was selected for molecular identification and the rDNA-ITS (GenBank accession No. ON918599), EF-1α (OR808022), β-tubulin (OP053690) and RPB2 (OP369287) gene sequences were 99.25%, 99.86%, 98.42% and 98.17% similar to those of Fusarium solani isolates (MT896771, ON843639, ON366357 and XM_046273849, respectively). Thus, the fungus represented by isolate YX39-1 was identified as F. solani based on cultural and morphological features. Pathogenic test showed that all inoculated plants exhibited symptoms similar to those observed in the field and YX39-1 was a strong pathogenic strain. The morphological and molecular identification of the fungal reisolated from inoculated plants confirmed its identity as F. solani, fulfilling Koch’s postulates. This is the first report of cigar wilt disease caused by F. solani causing in Lincang, Yunnan Province, China, which provides important information on the pathogen for disease management.

Maize yellow mosaic virus (MaYMV) as a newly identified Polerovirus causes leaf reddening in maize and yellow dwarf in wheat, leading to severe economic loss. In this study, the CP gene was amplified by RT-PCR from MaYMV-infected maize leaves, cloned into a prokaryotic expression vector pET28a (+) and transformed into the Escherichia coli strain BL21. The recombinant CP protein was expressed after induction with IPTG and used to prepare the antiserum by injection into New Zealand white rabbits. In-ELISA results showed that the titer of the antiserum was 1.024 × 10⁶. Dot-ELISA and Western blot analysis confirmed that the sensitivity of the antiserum to the MaYMV leaf sap was 1: 500, and the antiserum reacted specifically with MaYMV CP. These results indicate that the antiserum of MaYMV CP could be used for rapid detection of MaYMV. This study will provide an important basis for the monitoring and prediction of MaYMV.