Wheat stripe rust is one of the airborne fungal diseases that threaten the safety of wheat production. The emergence of new races of Puccinia striiformis f. sp. tritici (Pst) leads to the loss of the resistance of wheat cultivars, and causes disease epidemics due to its rapid accumulation and spread in oversummering variable areas of the pathogen. Qinghai Province is an important oversummering epidemic area of wheat stripe rust in China, in which the causal agent Pst can infect Berberis to complete sexual cycle. Therefore, determining the proportion of Pst infecting Berberis plants in Qinghai Province under natural conditions is very important to understand the roles of alternative host Berberis being attacking by the sexual reproduction of Pst and providing inoculum causing stripe rust on wheat. In this study, 1860 aecial samples collected from Berberis growing in main wheat-planting areas in Qinghai Province from 2022 to 2024 were used to determine Pst using combined methods of inoculation on susceptible wheat cultivar and detection with the Pst-specific molecular markers. As a result, the isolation rates of Pst from aecial samples in the three years were 2.72%, 4.10% and 2.38%, respectively, with an average of 3.07%. The detection rates based on molecular markers were 23.22%, 27.42% and 20.48%, respectively, with an average of 23.71%, with the highest isolation rate and detection rate in 2023. Therefore, in Qinghai Province Pst can infect the alternative host Berberis to complete sexual reproduction under natural con-ditions, with a high proportion. The results provide a clue for understanding the generation of new races of Pst and the origin of inoculum causing wheat stripe rust. Thus, it is necessary to strengthen effective management of sexual reproduction of Pst in the oversummering variable area in Qinghai Province for the prevention and control of wheat stripe rust in the local and national areas.

Root rot was found in main durian-planting areas in Hainan Province. The symptoms include root and root crown rot, which resulted in reduced tree vigor (leaf yellowing, leaf drop), branch wilt, even the death of entire tree. This causes serious economic losses to durian production. To identify the causal agent of this disease, diseased root samples of durian trees were collected from Sanya, Ledong, Lingshui and Baoting in Hainan Province from 2023 to 2024, and tissue isolation method was used to obtain potential pathogens. Based on morphological characteristics, phylogenetic relationship inferred from rDNA-ITS, Ypt1, β-Tubulin and EF-1α, and the result of pathogenicity test, the pathogen was identified as Phytophthora palmivora. This is the first report of durian root rot caused by P. palmivora in China.

A stem rot disease was found on Ficus virens and Ficus concinna in Hainan Province, China, in 2022. The diseased plants showed symptoms of sparse crowns with chlorotic leaves and dead branches, and even died when severely damaged. Yellow brown semi-circular basidiocarps were usually observed at the base of diseased trees in rainy and humid seasons. To identify the causal agent of the disease, conventional tissue isolation methods was adopted for pathogen isolation from diseased samples, and the representative strains HNQHHGR20221003001 and HNDXXYR2023051804 were used for pathogenicity test and morphological and molecular identification. Based on morphological characteristics, phylogenetic relationship inferred from rDNA-ITS, SSU and LSU, and the result of pathogenicity test, the pathogen was identified as Ganoderma australe. This is the first report of stem rot caused by G. australe on Ficus microcarpa in China. The results provide a basis for the control of the disease.

In the newly built apple orchard in Shilin County in central Yunnan, the incidence rate of apple root rot exceeded 20% and had been increasing by more than 10% annually, resulting in significant financial losses for fruit farmers. This study aims to clarify the pathogen and whether there are new pathogenic bacteria, so as to develop comprehensive prevention and control technologies and curb the epidemic of the disease. Samples of typical diseased plants were collected and subjected to tissue isolation methods for the isolation of pathogenic bacteria. The pathogenicity of the bacteria was confirmed through inoculation tests, and their preliminary classification was based on morphological characteristics. Furthermore, molecular biology identification was conducted using multilocus genes including internal transcribed spacer (ITS), β-tubulin (β-TUB), and histone H3 (HIS3). Through a combination of morphological and molecular biology identification methods, the pathogen responsible for apple root rot was conclusively identified as Ilyonectria vredehoekensis. This discovery represents the first report of apple root rot caused by I. vredehoekensis, laying a foundation for developing epidemic monitoring and integrated control technologies to manage this disease outbreak.

In 2021, a tea plant leaf spot disease was found in the Jin Xuan tea plants( Camellia sinensis cv.Jinxuan). A representative strain was isolated from the diseased leaves according to Koch’s postulates. The isolates were further identified as Cladosporium cladosporioides based on morphological characteristics and phylogenetic analysis with internal transcribed spacer region (ITS) and β-Actin gene. The results showed that the pathogen causing the disease was Cladosporium cladosporioides. This is the first report of Cladosporium cladosporioides in tea plants in China

Morus alba is an important economic tree. In 2023, a new foliar disease of mulberry tree occurred in Longchuan of Yunnan Province, China. Irregularly shaped brown spots were exhibited on the surface of infected leaves, with small black dots on the adaxial surfaces of blotches. In pathogenicity test, small brown lesions were observed surrounding the inoculation sites of wounded leaves after 5 days, resembling the symptoms that occurred in the field. The conidia of the pathogen are fusiform, erect or slight curving, with 4 septa, 1-4 hyaline apical appendages and a size of (22.11-26.58) μm×(4.62-6.31) μm long. Based on morphological characteristics and multi-locus phylogenetic analysis involving internal transcribed spacer (ITS), translation elongation factor 1 gene (tef1) and beta tubulin gene (tub2), and pathogenicity test result, the pathogen of mulberry leaf spot was identified as Pestalotiopsis camelliae. To our knowledge, this is the first report of P. camelliae causing leaf spot on mulberry tree in China.

Soft rot of konjac was found in main konjac-planting areas in Shangluo region of Shaanxi Province, China. The symptoms include petiole and corm rot, which result in leaf yellowing and wilt, even the death of entire plant. This has caused serious economic losses to konjac production. To identify the causal agent of this disease, petiole and corm samples of konjac with typical symptoms of soft rot were collected from Shanyang, Danfeng and Shangnan counties in Shangluo region from 2023 to 2024, and tissue isolation method was used to obtain potential pathogens. Based on morphological and biochemical characteristics, phylogenetic relationship inferred from full genome and the 16S rRNA sequence, and the result of pathogenicity test, the pathogen was identified as Raoultella ornithinolytica. This is the first report of konjac soft rot caused by R. ornithinolytica in the world.

Areca palm latent totivirus 1 (APLTV1) is a newly discovered virus that infects areca palms in Hainan Province. The objective of this study is to reveal the molecular evolutionary characteristics of the APLTV1 population in this province. Thirty-one randomly selected APLTV1-positive samples were subjected to genome sequence amplification, followed by sequence and phylogenetic analyses. The complete sequences of the 31 APLTV1 isolates from Hainan were all determined to be 4764 nucleotides in length, sharing a high sequence identity of 98.02% to 99.12% with the representative XS-3 isolate of APTLV1. Within the APLTV1 genome, two open reading frames (ORFs) were identified encoding the coat protein (CP) and the RNA-dependent RNA polymerase (RdRp), respectively. Negative selection was found at the majority of polymorphic sites within the RdRp and CP genes, whereas positive selection was found exclusively at polymorphic sites within the CP gene. Phylogenetic analysis revealed that all isolates of APLTV1 could be separated into two distinct clades. The results obtained from this study provide valuable insights into understanding the epidemiology and molecular variation of APLTV1.

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.

In this study, the fungal strain LD-11 was isolated from the infected plant of Lonicera caerulea (cv Lanjingling) collected in the horticulture experimental station of Northeast Agricultural University, Harbin, Heilongjiang Province. The strain was identified as Epicoccum nigrum by morphology, rDNA-ITS, LSU, TUB, RPB2 gene sequence amplification and phylogenetic tree construction. The experimental results showed that E. nigrum LD-11 could grow on PDA, OA and MEA medium. The optimal culture medium was OA, and the optimal culture conditions were growth temperature of 25 ℃, pH 6, carbon source is starch and nitrogen source is yeast extract, and full light conditions were conducive to mycelial growth. This study is the first time to isolate and identify E. nigrum, the pathogen of leaf spot disease in L. caerulea, which will provide an important source of pathogenic fungi for future research on control of plant disease.

Polygonatum kingianum Coll. et Hemsl., a perennial herbaceous plant belonging to the family Liliaceae, has special medicinal and dietary values. Rhizome rot, usually leading to the decrease of yield and quality, is a frequently occurred disease on P. kingianum in Yunnan Province. In this study, diseased P. kingianum samples with typical symptoms of rhizome rot were collected, and a representative fungal strain 19-1 was obtained by tissue isolation and single spore purification. The pathogenicity of strain 19-1 to P. kingianum was tested and confirmed by irrigating inoculation of plant seedlings with spore suspension (1×10⁶ spores·mL^-1). According to morphological characteristics and multigene-based phylogenetic analysis results, strain 19-1 was identified as Fusarium concentricum. This is the first report of F. concentricum causing rhizome rot on P. kingianum. Our results provide a theoretical basis for further investigation of the epidemiology and integrated control of the disease.

Pittosporum tobira is used as a evergreen plant in urban landscape. In recent years, a serious leaf disease was found on P. tobira in Chongqing, which seriously affected the ecological and landscape benefits. Disease incidence ranged from 20% to 50% in the affected fields. In this study, the pathogens of this disease were isolated and verified by Koch’s rule. The strain were identified as Colletotrichum fioriniae based on morphological characteristics and rDNA-internal transcribed space(ITS)、actin(ACT)、β-tubulin(TUB2) and glyceraldehyde-3-phosphate dehydrogenase(GAPDH) gene sequence analysis. The identification of the pathogen of anthracnose in P. tobira will provide theoretical basis for further study of disease monitoring and control.

Avena sativa is an important crop for food and feed in the world. During the investigation of oat diseases in Hohhot in 2022, a new disease was found which produced long spindle-shaped necrotic lesions on oat sheath with black spots in the center. More strains with the same colony morphology were generated from the diseased sheath tissues. One representative strain QSH2-3-2 was selected for pathogenicity test. The results show that strain QSH2-3-2 can cause necrotic spots on oat leaves and sheaths. It was identified as Didymella glomerata by morphological characteristics and multi-locus DNA sequence analysis. To our knowledge, this is the first report that D. glomerata was the pathogen of oat spot blight.

Grapevine (Vitis vinifera L.), is known as the first of the world’s four fruits, both fruit and medicinal value. Recently, ‘shine muscat’ and ‘Christmas Rose’ were premium varieties of grapevine. From May 2022 to May 2023, a fruit drop and rot disease was found on grapevine in Zhaoqin city, Guangdong province. To clarify the reason of this phenomenon, the pathogen was isolated and purified by tissue separation method, and its pathogenicity was confirmed based on the Koch’s postulates. According to morphological features and phylogenetic analysis of rDNA-ITS and EF-1α gene, the pathogen was identified as Aspergillus aculeatus. To our knowledge, this is the first report of A. aculeatus causing fruit rot on grapevine in China. The results will provide scientific basis for effective control of the disease on grapevine.

In 2023, a typical sample of root rot of Idesia polycarpa was collected in Zunyi city, Guizhou Pro-vince, China, and the pathogenic strain was obtained by tissue separation method. According to Koch’s rule, pathogenicity test, morphological characteristics and ITS, TEF1-α and TUB multigene phylogenetic analysis, the pathogen was identified as Fusarium solani. The results provided a theoretical basis for the field control of the root rot of Idesia polycarpa. This is the first time to report the root rot of I. polycarpa induced by F. solani in China.

Xinjiang wild apricot (Prunus armeniaca) has strong resistance to drought and cold. It is an important genetic resource for breeding. In 2021, twenty leaf samples of Xinjiang wild apricot were collected in the wild forests of Tianshan Mountain in YiLi, Xinjiang. Using high-throughput sequencing and RT-PCR, peach chlorotic leaf spot virus (PCLSV) and mume-associated luteovirus (MaLV) were identified. Whole genomes of these two viruses were obtained by RT-PCR and RACE. After removing poly (A), the genome of PCLSV from Prunus armeniaca (PCLSV-YX) contains 7 462 nucleotides (nts) with three overlapping open reading frames (ORFs). The genome of MaLV from Prunus armeniaca (MaLV-YX) contains 5 753 nts, and has six ORFs. Phylogenetic analysis showed that PCLSV-YX was closely related to isolates of ‘PR19-2’ and ‘TaTao’. MaLV-YX was closely related to cherry-associated luteovirus (ChALV), prunus mahaleb-associated luteovirus (PmALV), peach-associated luteovirus (PaLV) and peach-associated luteovirus 2 (PaLV2).

Morinda officinalis is a Chinese traditional herbal medicine in the family Rubiaceae. From April to June 2023, the southern blight disease occurred seriously on M. officinalis in Zhangzhou City, Fujian Province, China. The white mycelia and sclerotia of the pathogen were initially observed at the stem-soil interface of diseased seedlings, and gradually spread to neighboring plants, which resulted in the death of patches of plants. Fungal strains with same morphological characteristics were obtained from the diseased samples by using the tissue isolation method. Based on morphological characteristics, ribosomal large subunit (LSU) sequences and pathogenicity test, the representative fungal strains were identified as Sclerotium rolfsii Sacc. To our knowledge, this is the first report of S. rolfsii causing southern blight on M. officinalis, which provides important information on the pathogen for disease management.

Anthracnose is one of the most important fungal diseases that pose significant threat to the production of Yunnan red pear cultivar ‘Caiyunhong’. The disease mainly causes fruit rot, resulting in a disease incidence of more than 35% in normal conditions. The causal agent was identified as Colletotrichum fructicola based on the morphological characteristics, phylogenetic relationship inferred from ITS, ACT, TUB and CHS sequences, and the result of pathogenicity test. This is the first report of C. Fructicola causing anthracnose on ‘Caiyunhong’ fruit in China, which provides a theoretical basis for effective prevention and control of the disease.

A leaf spot of Polygonatum kingianum was found in Jianxing Town, Xinping County, Yunnan Province. Leaf infections first appeared as small, pale brown spots with a yellow haloes. The spots extended or coalesced into larger lesions, causing the entire leaf to be necrotic. The pathogen causing this disease was isolated, and its pathogenicity was tested according to the Koch' s postulates. Based on morphological characteristics and phylogenetic analysis of combined the rDNA 18S and ITS regions as well as beta-tubulin (TUB) gene sequences, the isolate DYB-2 was identified as Neopestalotiopsis acrostichi. To our knowledge, this is the first report of N. acrostichi causing the leaf spot on Polygonatum kingianum in the world.

To clarify the species and biological characteristics of the pathogenic fungi that cause root rot of Ficus virens in Hainan Province, pathogenic fungi were isolated from diseased tissue and basidiocarps collected from the root of the diseased tree of Ficus virens in March 2022 by tissue separation method. The pathogenic bacteria causing the root rot disease were identified through pathogenicity determination, combing with morphology identification and molecular identification. The effects of pH, temperature, medium and light on mycelium growth under different treatments were measured by cross crossing method. The results showed that the isolated pathogenic ganoderma strain was the pathogen causing the root rot of Ficus virens. After morphological characterization and jointly phylogenetic tree construction based on rDNA-ITS, rDNA-LSU and rDNA-SSU, the pathogen strain was identified as Ganoderma tropicum. The biological characteristics showed that the optimal medium was PDA medium, the optimal pH was 7.0, the optimal light condition was total darkness, and the optimal growth temperature was 32 ℃.It will provide scientific theoretical basis for the diagnosis and control of this disease.

In recent years, the planting area of Prunus serrulata in Henan Province has been increasing, and the disease problem is becoming more and more serious. A canker disease that infects the branches of P. serrulata has been observed in many areas; it causes brown canker tissue on the shoots, twigs and kills the branches. To clarify the pathogen causing shoot canker of P. serrulata in Henan Province, isolates were obtained from diseased shoots and identified based on the morphological and molecular biological methods. In this study, a total of 21 strains with the same morphological characteristics were obtained and Koch’s postulates was verified. According to its morphological and molecular biological characteristics, the pathogen causing shoot canker of P. serrulata in Henan Province was finally identified as Diaporthe eres. This is the first report of D. eres responsible for P. serrulata shoot canker. The optimum growth temperature of D. eres was 25 ℃, and the optimum pH was 6, the optimum carbon source was sucrose, the optimum nitrogen source was yeast powder.

From 2020 to 2022, a new disease, basal stem rot of Achyranthes bidentata was prevalent in the field in Wuzhi county, Jiaozuo city, Henan province. The incidence of severe disease plot was over 90%, that seriously affected the yield and quality of A. bidentata. Tissue isolation and culture method was used to isolate and purify the pathogen from disease samples of A. bidentata with the typical symptoms of stem rot. Based on the morphological identification, sequence analysis of ITS and TEF-1α, and pathogenicity assays, the pathogen were identified as Rhizoctonia solani, and belonged to anastomosis subgroup (AG)-4-HGI. This is the first report of R. solani AG-4-HGI causing basal stem rot on A. bidentata in China, the results of this study could provide useful guidance for the effective prevention and control of A. bidentatae basal stem rot.

Mycoleptodiscus terrestris is a pathogen on many legumes, but there are very few reports about it occurring on peas. In May 1989, the pathogenic fungus producing black microsclerotia was isolated from diseased roots of pea in Dingxi city, Gansu province. Due to limited knowledge and the lack of important literature at that time, the fungus was named as Burgoa pisi in 1998. In May 2018, several fungal strains with the same morphological characteristics as B. pisi were isolated from diseased pea roots and hypocotyls in Huining county, Gansu province. The optimum mycelial growth temperature of tested strains was 25-30 ℃. When cultured on PCA medium at 30 ℃ for 14 d, the strains produced abundant of microsclerotia, the microsclerotia were nearly spherical to irregular, (104.5-567.2) μm × (95.5-343.3) μm, and there were 0 to dozens of setae on the sclerotial surface, the setae were multicellular and columnar, the basal cells were colorless or pale, and the terminal cell was black thick-walled (sheath-like), straight, slightly curved or short forked. However, when on PDA and PCA media at 25-30℃ for 21 days, no conidia produce, and they also failed to induce conidia by soybean leaves inoculation in vivo. BLASTn analysis showed that the sequences of strain TCD-11 (GenBank accession No. ITS: OL981504; LSU: OL981961) and TCD-28 (GenBank accession No. ITS: OL981505) had a 99.45% similarity in the ITS region and 100% identity in the LSU region with M. terrestris ex-type strain CBS 231.53 (GenBank accession No. ITS: MK487754.1; LSU: MK487730.1). In the combined phylogenetic tree of rDNA-ITS and LSU sequences, tested strains TCD-11 and TCD-28 were clustered with M. terrestris strains in same group. Pathogenicity test showed that the tested strains had aggressive pathogenicity to the root and epicotyl of pea (Pisum sativum) (included edible pod pea and edible seed pea), the infected roots and hypocotyls showed extensive brown to dark brown spots; they had weak pathogenicity to broad bean (Vicia faba) of Fabaceae, only small restricted black necrotic spots were formed at the inoculation site. The pathogen was reisolated from all infected pea and broad bean plants and had the same morphology as isolates TCD-11 and TCD-28, fulfilling Koch’s postulates. According to morphological and molecular biological characters, tested strains are identified as M. terrestris, and B. pisi in essence is a synonym of M. terrestris.

Paris polyphylla var. yunnanensis (Franch) Hand.-Mazz is an important cash crop in Yunnan ethnic minority areas. In 2022, we discovered a new type of leaf spot disease in the Lijiang planting area, which can damage the entire growth period of the crop. The typical symptoms in the field were spots(diameter 2.4-6.7 mm) on the surface of the disease leaves, the leave become brown and necrosis in later stage thus resulting in serious economic losses. We isolated pathogenic bacteria by monosporophyte isolation,and identified by morphological observation and polygenic phylogenetic analysis, and its pathogenicity was verified using Koch’s rule.The final identification results showed that the pathogen was a new species of Cercospora and was named Cercospora polyphylla x.he & P. W. Yang, sp.11 according to the binomial nomenclature.This is the first report of Paris polyphylla var. yunnanensis (Franch) Hand.-Mazz leaf disease caused by C. polyphylla in China, and this study will provide a theoretical basis for the epidemic and comprehensive prevention and control of the disease.

Verticillium wilt of Chinese cabbage is an emerging disease in Qinghai Province. The symptoms of verticillium wilt is discoloration of the vascular bundle of roots, blackening and discoloration of stems or leaf veins which may extend to the whole leaves and death in severe case. This study isolated and cultured 24 strains from 10 Chinese cabbage samples in Qinghai Province and detected the strains with morphological observation, DNA sequence analysis, and pathogenicity test to determine the pathogen. Morphological observation showed that the strain QH-87 grew very slowly on potato dextrose agar medium with a large number of black microsclerotia( (5.8-27.8) μm × (35.3-356.8) μm), and the length to width ratio was 2.3-25.6. Conidia were transparent and cylindrical and its size was (2.1-5.4) μm × (4.5-11.9) μm. Chlamydospores and dormant hyphae were not observed. The fungus was verified as Verticillium longisporum lineage A1/D1 according to the results of ITS, ACT and EF sequencing. The pathogenicity test showed that strain QH-87 could infect Chinese cabbage and caused discoloration and wilt. In a word, the pathogen was identified as V. longesporum lineage A1/D1. It is the first report of verticillium wilt of Chinese cabbage in Qinghai province, and V. longisporum lineage A1/D1 is first reported on Chinese cabbage in China.

In the autumn of 2019, a new leaf spot disease was discovered on Zizania latifolia plants in two locations, Langya in Jinhua, and Daji in Lishui, Zhejiang Province. We isolated the pathogen using tissue separation method, and identified it as Epicoccum sorghinum through multiple methods, including morphological observation, biological identification and pathogenicity test. Besides, to prevent the effect of E. sorghinum on the yield and quality of Z. latifolia, 12 chemical fungicides were screened. Among these, prochloraz showed the best inhibitory effect on the pathogen. Additionally it had the least side effect on the growth of Ustilago esculenta, another mutually beneficial organism associated with Z. latifolia. So prochloraz can be used as an effective fungicide for the disease management. This study provides a scientific basis for the identification and understanding the leaf spot disease in Z. latifolia. It offers insights into the selection of chemical fungicides for its control, which is valuable for agricultural and disease management.

In recent years, apple diaporthe neck and root rot has become one of the most important limiting factors for the development of apple production in Yunnan Province. In this study, the typical disease samples were collected and the fungal isolate M2g7-1 was obtained by tissue separation approach. The purified culture M2g7-1 was preliminary determined belonging to Diaporthe spp. based on the morphological features of colony, pycnidia, cirrus, two forms of conidia. The pathogenicity of M2g7-1 was further validated on apple young branches to fulfill the Koch's law. The taxonomic of pathogen M2g7-1 has been further determined with combining molecular phylogenetics. The phylogenetic tree was created with the data set of sequences from the internal transcribed spacer (ITS) of ribosomal DNA, the histone H3 (HIS) gene, the translation elongation factor 1-alpha (TEF) gene, and the beta-tubulin (TUB) gene. Based on morphological and molecular biology analysis, the pathogen M2g7-1 was finally identified as Diaporthe eres. This is the first report of D. eres as the pathogen of apple diaporthe neck and root rot. The research results provide a theoretical basis for the epidemic research and comprehensive control of this disease.

Bletilla striata is one of the genuine medicinal materials in Guizhou, and its planting area ranks first in China. In 2022, the leaf blight of Bletilla striata occurred in Guizhou Academy of Agricultural Sciences with a large area and was serious. In this study, the pathogenic fungus was isolated from the leaves with obvious symptoms, which was identified to be Rhizoctonia solani AG1-IB based on the results of morphological identification, ITS sequence analysis, and hyphal anastomosis. To our knowledge, there have been no reports on the isolation of R.solani AG1-IB from Bletilla striata in China as so far. This is the first report and the results will provide theoretical reference for effective control and further research of leaf blight on Bletilla striata.

Citrus is one of the most important fruits in China and is cultivated extensively in southern China. Fusarium fujikuroi has been reported to cause diseases on various plants excluding citrus worldwide. In this study, by using tissue separation method, 23 Fusarium-like isolates were isolated from diseased citrus leaves from eight different citrus planting areas in Hubei province. STJ-4 was selected as a representative isolate for further analysis, which included analyses of morphological characteristics, partial sequences of ITS, EF-1α, and RPB1 genes, phylogenetic trees based on the three genes and pathogenicity. Results showed that the STJ-4 isolate was identified as F. fujikuroi, which is the first report of F. fujikuroi causing leaf rot disease on citrus. Our study is important for developing the prevention strategies against F. fujikuroi in the future.

Brown rot symptoms on fruit of Lucuma nervosa were observed in Guangxi South Subtropical Agricultural Science Research Institute. The samples were collected from the field, the pathogen was isolated by tissue isolation, and its pathogenicity was verified by the Koch′s rule. The pathogen was identified as Lasiodiplodia pseudotheobromae by combining morphological characteristics and ITS-TUB-RPB2-TEF1 sequence analysis. This is the first report of Lasiodiplodia pseudotheobromae causing brown rot on Lucuma nervosa fruit in the world.

As an important ornamental plant, hollyhock (Alcea rosea L.) plays an important role in landscape architecture. In May 2023, a new rust disease on A. rosea was observed in Guiyang, Guizhou Province. Rust infected various parts of A. rosea and seriously reduced the ornamental value. In this study, the teliospores were collected from the diseased leaves of A. rosea. Based on the morphological characteristics and phylogenetic analyses of internal transcribed spacer (ITS) and large subunit (LSU) sequences, the rust pathogen was identified as Puccinia modiolae. This is the first report of P. modiolae causing rust disease on A. rosea in China. These findings will promote further research on rust disease on A. rosea and provide a scientific basis for its control.

As a famous fruits of the tropics and subtropics,the overall growth of Hylocereus polyrhizus have been seriously affect by a mature stem blight disease found in the regions of H. polyrhizus plantations in Danzhou city,Hainan province of China in 2022. It caused extensively grayish-white blight of the diseased stems. The pathogen isolated from the diseased plants was identified as Diaporthe passiflorae,based on pathogenicity test,morphological traits and phylogenetic analyses of multi-loci (ITS,TUB2,CAL,TEF1-α and HIS3). The results provide a theoretical basis for the field control of stem blight of H. polyrhizus.

Cherry tomato (Solanum lycopersicum var. cerasiforme) is an important crop in Hainan Province, and its production is seriously damaged by viral diseases. To identify the viruses infecting cherry tomato, LncRNA sequencing was performed using leaf samples from diverse geographical locations with typical viral symptoms. The virome of cherry tomato comprises eight viruses─ageratum yellow vein virus (AYVV), cucumber mosaic virus (CMV), southern tomato virus (STV), tobacco mosaic virus (TMV), tomato chlorosis virus (ToCV), tomato mosaic virus (ToMV), tomato mottle mosaic virus (ToMMV) and tomato yellow leaf curl virus (TYLCV). The PCR detection results of 234 cherry tomato leaf samples from nine cities and counties indicated that the dominant viruses are TYLCV (69.23%), ToCV (49.57%) and ToMMV (35.47%), followed by STV (23.50%), ToMV (17.52%), CMV (17.52%), AYVV (16.24%) and TMV (10.68%). The ratio of mixed virus infection was 81.62%. Complete genomes of two AYVV isolates (AYVV-tomato-LS1 and AYVV-tomato-LS2) and one TYLCV isolate (TYLCV-tomato-LS) in the genus Begomovirus were obtained using PCR with back-to-back primers. The pairwise comparison of genomes of AYVV-tomato-LS1 and AYVV-tomato-LS2 were 98.98% nucleotide identical to each other, sharing their maximum nucleotide identities at 92.71% and 92.81% with AYVV-SY08 (GenBank accession no.: KC810890), and were phylogenetically closely related to the AYVV isolates from diverse hosts from Hainan. TYLCV-tomato-LSs shared their maximum nucleotide identities at 96.52% with TYLCV-HNLS (GenBank accession no.: MK908814), and were phylogenetically closely related to the TYLCV isolates from diverse hosts from Hainan, followed by Capsicum annuum isolates from Spain (GenBank accession no.: AJ489258). Our findings provide support for sustainable control strategies for cherry tomato virus disease in Hainan, China.

White root rot is one of the most important root diseases of grape. From 2021 to 2022, the symptoms of white mycelium on the surface of grape roots were observed in several grapevines in Shanxi Province, China, with the incidence of 26.74%. Symptomatic root samples were collected and taken back to the laboratory to isolate the fungi. In this study, twenty strains were obtained by single hyphal purification. Based on the morphological characteristics and multi-gene (ITS, LSU and TUB2) phylogenetic analysis, these strains were identified as Rosellinia necatrix. To confirm the pathogenicity, the inoculation was performed by adding wheat seeds colonized by R. necatrix in the soil. The results showed that R. necatrix was pathogenic to the grape. To our knowledge, this is the first report of R. necatrix causing white root in Shanxi province, China.

Gummy stem blight, usually seen on the stems, leaves and fruits, is one of the most serious threats to production of pumpkin (Cucurbita moschata Duch.) in Hebei with reduction of the quality and heavy losses in yield. The pathogenic organisms of the disease were still obscure because several fungal species with most similar morphology were reported to be the causative agents. A fungal pathogen NG2023021301-4 was isolated from the diseased tissue and purified by single-spore isolation. According to morphological characteristics and combinatory phylogenetic analysis of ITS region, TUB gene sequences, the pathogen was identified as Stagonosporopsis caricae. To our knowledge, this is the first report of S. caricae causing verticillium wilt of pumpkin fruits.